CN116681605A - Image tone mapping method, device, electronic device and storage medium - Google Patents

Abstract

The application provides an image tone mapping method, an image tone mapping device, electronic equipment and a storage medium, and relates to the technical field of image processing. When the method maps the HDR picture to the LDR picture, the tone mapping curve corresponding to the target picture style is called to carry out tone mapping according to the target picture style of the LDR picture to be mapped to the HDR picture, so that the display effect of the LDR picture obtained after mapping is better. Aiming at different picture style processing requirements of users, tone mapping processing can be performed by adopting tone mapping curves matched with picture styles, and the problem that the tone mapping curves are relatively poor in effect of LDR pictures obtained after tone mapping caused by single fixation because the tone mapping curves correspond to the same tone mapping curves in different picture styles is avoided. In addition, the scheme establishes the mapping relation between the picture style and the tone mapping curve based on the objective standard, and avoids the problem that the effect of the processing result caused by processing by depending on subjective consciousness is not measurable.

Description

Image tone mapping method, device, electronic device and storage medium

Technical Field

The present application relates to the field of image processing technology, and in particular to an image tone mapping method, device, electronic device and storage medium.

Background Art

Currently, most game scenes are HDR (high dynamic range) pictures. The brightness value of the picture rendered by HDR will exceed the maximum value that the monitor LDR (low dynamic range) can display, resulting in image quality problems such as overexposure and loss of bright details on the display. Therefore, it is necessary to convert the HDR picture into an LDR picture that the monitor can display normally to ensure the integrity of the displayed picture.

In the prior art, a fixed tone mapping curve built into the game engine is used to convert the HDR picture to the LDR picture. However, it cannot meet the conversion requirements of various style effects of the game picture, resulting in poor picture conversion effect in some scenes.

Summary of the invention

The present application provides an image tone mapping method, device, electronic device and storage medium to improve the tone mapping effect of pictures of different styles.

The technical solutions adopted in the embodiments of this application are as follows:

In a first aspect, an embodiment of the present application provides an image tone mapping method, comprising:

Acquire color information of a first picture to be processed, where the first picture is a high dynamic range picture;

Determining a target picture style of a second picture to be mapped from the first picture, and a target tone mapping curve corresponding to the target picture style; the second picture is a low dynamic range picture;

Performing tone mapping processing on the color information of the first picture by using the target tone mapping curve to obtain color information of a second picture corresponding to the first picture;

The second picture is generated according to the color information of the second picture, and the picture style of the second picture is the target picture style.

In a second aspect, an embodiment of the present application further provides an image tone mapping device, including: an acquisition module, a determination module, a processing module, and a generation module;

The acquisition module is used to acquire color information of a first picture to be processed, where the first picture is a high dynamic range picture;

The determination module is used to determine a target picture style of a second picture to be mapped from the first picture, and a target tone mapping curve corresponding to the target picture style; the second picture is a low dynamic range picture;

The processing module is used to perform tone mapping processing on the color information of the first picture by using the target tone mapping curve to obtain color information of the second picture corresponding to the first picture;

The generating module is used to generate the second picture according to the color information of the second picture, and the picture style of the second picture is the target picture style.

In a third aspect, an embodiment of the present application provides an electronic device, comprising: a processor, a storage medium and a bus, wherein the storage medium stores machine-readable instructions executable by the processor. When the electronic device is running, the processor and the storage medium communicate through the bus, and the processor executes the machine-readable instructions to perform the image tone mapping method provided in the first aspect.

In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the image tone mapping method provided in the first aspect is executed.

The beneficial effects of this application are:

The present application provides an image tone mapping method, device, electronic device and storage medium. When converting an HDR picture to an LDR picture, the tone mapping curve corresponding to the target picture style is called to perform tone mapping according to the target picture style of the LDR picture to which the HDR picture is to be mapped, so that the display effect of the LDR picture obtained after mapping is better. According to the different picture style processing requirements of users, the tone mapping process can be performed using a tone mapping curve that matches the picture style, avoiding the problem that different picture styles correspond to the same tone mapping curve, and the LDR picture effect obtained after tone mapping is poor due to the single and fixed tone mapping curve. And compared with the method of manually adjusting the tone mapping curve based on experience and visual observation, this scheme establishes a mapping relationship between the picture style and the tone mapping curve based on objective standards, so that the processing result obtained after the tone mapping process using the tone mapping curve corresponding to the picture style is more convincing, and the quality of the processing result has a measurement standard, avoiding the problem that the quality of the processing result cannot be measured due to relying on subjective consciousness.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of a flow chart of an image tone mapping method provided in an embodiment of the present application;

FIG2 is a schematic diagram of a flow chart of another image tone mapping method provided in an embodiment of the present application;

FIG3 is a schematic diagram of a tone mapping curve provided in an embodiment of the present application;

FIG4 is a schematic diagram of another tone mapping curve provided in an embodiment of the present application;

FIG5 is a schematic diagram of a flow chart of another image tone mapping method provided in an embodiment of the present application;

FIG6 is a schematic diagram of an image tone mapping device provided in an embodiment of the present application;

FIG. 7 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

DETAILED DESCRIPTION

To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

In addition, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

First, some terms that may be involved in the embodiments of the present application are explained:

Tone mapping: Tone mapping is a computer graphics technique that approximates the display of high dynamic range images on limited dynamic range media.

HDR (high dynamic range): high dynamic range.

LDR (low dynamic range): low dynamic range.

RGB: three primary colors: red, green and blue.

HSV: H (Hue) stands for hue, S (Saturation) stands for saturation, and V (Value) in HSV is the value, which indicates the brightness of the color.

AECS (Academy Color Encoding System): The Academy Color Encoding System is the industry standard for managing color throughout the life cycle of film or television production. It is a free, open, device-independent color management and image exchange system.

Hue: Hue refers to the relative lightness or darkness of an image, and is represented as color in color images.

Hue: Hue is color. Adjusting hue is adjusting the color of the image.

Saturation: Saturation refers to the intensity of the image colors.

Value: Value refers to the lightness or darkness of a color.

Contrast: Contrast refers to the difference between different colors.

Brightness: Brightness is also called light brightness, which indicates the brightness of the light source or the surface of the illuminated object.

Next, the relevant background of this plan is explained:

At present, most game scenes are HDR pictures. The brightness value of the picture rendered by HDR will exceed the maximum value that the monitor (LDR) can display, which makes the HDR picture overexposed when displayed on the LDR monitor, and the details of the picture cannot be seen. In order to ensure the display effect of the HDR picture, we need to convert the lighting result from HDR to LDR that the monitor can display normally. We usually call this process Tone mapping. After compression with Tonemapping, the HDR image we get can be displayed well on the monitor, and the hue, saturation, brightness, and contrast of the picture will change during the transformation. At present, most game engines have built-in adjusted Tone mapping, which can be applied directly if there is no special picture effect requirement.

However, although most game engines have built-in adjusted Tone mapping, the set Tonemapping is relatively simple and fixed, and cannot meet the various style effect requirements of the game screen, so stylized adjustments are needed.

The traditional way is to observe the changes in the displayed image by adjusting the Tone mapping algorithm. Since there is no picture measurement standard in this regard, adjustments can only be made based on personal experience and level, and most of them are judged by the human eye. Everyone's visual perception and standards are different, and it cannot be used as a universal standard. Therefore, it is necessary to find an objective standard to measure the processing picture styles applicable to different Tone mapping algorithms. In order to meet the processing requirements of different picture styles, the corresponding Tone mapping algorithm can be used for tone mapping, so that the LDR picture effect obtained after tone mapping of the HDR picture is better.

FIG1 is a flow chart of an image tone mapping method provided by an embodiment of the present application; the execution subject of the method may be a computer device. As shown in FIG1 , the method may include:

S101. Obtain color information of a first picture to be processed, where the first picture is a high dynamic range picture.

The first picture to be processed may refer to an HDR picture to be processed, that is, a high dynamic range picture.

S102, determining a target picture style of a second picture to be mapped from the first picture, and a target tone mapping curve corresponding to the target picture style; the second picture is a low dynamic range picture.

The target picture style refers to the picture style of the second picture to which the HDR picture to be processed is to be mapped. The target picture style can be customized according to user needs, or it can be pre-configured, with different HDR pictures to be mapped to the target picture style of the second picture.

The second picture here refers to the LDR picture, that is, through tone mapping processing, the color information of the HDR picture to be processed is processed to obtain the color information of the LDR picture corresponding to the HDR picture.

In this embodiment, a mapping relationship between different picture styles and different tone mapping curves can be established in advance, and the mapping relationship can be stored in the server background. After the target picture style is determined, the mapping relationship between the picture style and the tone mapping curve can be called to determine the target tone mapping curve corresponding to the target picture style.

Since different picture styles are matched with corresponding tone mapping curves, a matching tone mapping curve can be used for tone mapping according to different picture style processing requirements, thereby realizing personalized processing of different picture styles.

It should be noted that there are many algorithms for converting HDR images to LDR images, and using a tone mapping curve is one of the possible ways to achieve this. The principle of a tone mapping curve is to transform the color values of an image from one range distribution to another range distribution. Specifically, the color values are mapped from a large range to a smaller range, so that the mapped colors can be displayed on a display with a low dynamic range.

S103 . Perform tone mapping processing on the color information of the first picture using the target tone mapping curve to obtain color information of the second picture corresponding to the first picture.

Based on the determined target tone mapping curve, the target tone mapping curve may be used to perform tone mapping processing on the color information of the first picture to be processed, thereby obtaining color information of the second picture corresponding to the first picture.

S104: Generate a second picture according to the color information of the second picture, and the picture style of the second picture is the target picture style.

Optionally, an LDR picture can be generated based on the color information of the LDR picture, thereby converting the HDR picture to be processed into an LDR picture and displaying it on the display. Due to the tone mapping processing, the color of the part of the HDR picture that originally could not be displayed on the display is mapped to a smaller range, so that the color range of the second picture obtained after processing is smaller and can be displayed normally on the display.

In summary, the image tone mapping method provided in this embodiment, when converting an HDR picture to an LDR picture, will call the tone mapping curve corresponding to the target picture style to perform tone mapping processing according to the target picture style of the LDR picture to which the HDR picture is to be mapped, so that the display effect of the LDR picture obtained after mapping is better. In view of the different picture style processing requirements of users, a tone mapping curve matching the picture style can be used to perform tone mapping processing, avoiding the problem that different picture styles correspond to the same tone mapping curve, and the LDR picture effect obtained after tone mapping is poor due to the single and fixed tone mapping curve. And compared with the method of manually adjusting the tone mapping curve based on experience and visual observation, this scheme establishes a mapping relationship between the picture style and the tone mapping curve based on objective standards, so that the processing result obtained after tone mapping processing using the tone mapping curve corresponding to the picture style is more convincing, and the quality of the processing result has a measurement standard, avoiding the problem that the quality of the processing result cannot be measured due to relying on subjective consciousness.

FIG. 2 is a flow chart of another image tone mapping method provided by an embodiment of the present application; in step S102, before determining a target tone mapping curve corresponding to a target picture style, the method may further include:

S201. Acquire multiple test pictures, where the test pictures are high dynamic range pictures.

This embodiment collects a test picture, and performs tone mapping processing on the test picture using pre-created tone mapping curves to be tested, and tests the processing picture style corresponding to each tone mapping curve to be tested according to the processing result, that is, determines the processing picture style to which each tone mapping curve to be tested is applicable. In other words, it measures which picture style each tone mapping curve to be tested is suitable for mapping processing.

First, a standard test environment can be built, which may include: standard test charts, test material balls, and test lights. The test material balls are illuminated by test lights, and the changes in the grayscale brightness of the test material balls after illumination are observed. When the grayscale display shows an exposed state, the illumination is stopped, and a test screen is generated according to the current illumination state of the test material balls.

It is worth noting that multiple test pictures can be collected, and the test pictures are also HDR pictures, and there is a need to perform tone mapping processing.

S202 : Using the tone mapping curve to be tested to perform tone mapping processing on the test pictures respectively, to generate processed pictures corresponding to the tone mapping curve to be tested.

There may be multiple tone mapping curves to be tested, and each tone mapping curve to be tested is pre-made, but it is not known which style of picture each tone mapping curve to be tested is suitable for tone mapping processing. This embodiment constructs a mapping relationship between each tone mapping curve to be tested and each picture style through testing.

Optionally, for any tone mapping curve to be tested, the tone mapping curve to be tested may be used to perform tone mapping processing on the test picture, so as to generate a processed picture corresponding to the tone mapping curve to be tested.

In order to improve the accuracy of the test results, the test screen may include multiple test pictures. Then, for a tone mapping curve to be tested, the number of corresponding processed pictures generated corresponds to the number of test pictures. For example, when the test screen includes 3, the processed pictures corresponding to the tone mapping curve to be tested also include 3.

S203: Determine color information of the processed picture corresponding to the tone mapping curve to be tested.

According to the processed picture corresponding to the tone mapping curve to be tested, the color information of the processed picture corresponding to the tone mapping curve to be tested can be obtained respectively.

S204: Determine the processed picture style corresponding to the tone mapping curve to be tested according to the color information of the processed picture corresponding to the tone mapping curve to be tested and the standard test chart, and establish a mapping relationship between the tone mapping curve to be tested and the corresponding processed picture style.

Optionally, based on the color information of the processed picture corresponding to the tone mapping curve to be tested and the standard test chart, the color difference information between the color information of the processed picture corresponding to the tone mapping curve to be tested and the standard test chart can be statistically analyzed, so as to determine the processed picture style corresponding to the tone mapping curve to be tested based on the color difference information. The processed picture style corresponding to the tone mapping curve to be tested may also refer to the picture style that the tone mapping curve to be tested is suitable for processing.

Based on the above analysis, different tone mapping curves to be tested and their corresponding processed picture styles can be determined, so that mapping relationships between different tone mapping curves to be tested and different processed picture styles can be constructed and recorded.

In this embodiment, the color information of the processed picture after tone mapping processing of the test picture by different tone mapping curves to be tested is compared and analyzed with the color information of the standard test chart to obtain the data analysis result, and the mapping processing effects of different tone mapping curves to be tested are measured from the perspective of data quantification, so that the measurement result is more objective and convincing.

Optionally, different tone mapping curves to be tested have different mapping thresholds.

In the present embodiment, a plurality of tone mapping curves to be tested are pre-produced, and each tone mapping curve to be tested has a different mapping threshold, so that each tone mapping curve to be tested has a different picture style for the LDR picture obtained after mapping the same HDR picture, thereby realizing the testing of the mapping effects of more different tone mapping curves to be tested.

FIG3 is a schematic diagram of a tone mapping curve provided in an embodiment of the present application. The mapping threshold of the tone mapping curve shown in FIG3 is 1.25, wherein the horizontal axis of the tone mapping curve represents the color value (RGB value) of the HDR picture, ranging from 0 to infinity, and the vertical axis represents the color value (RGB value) of the LDR picture, ranging from 0 to 1, and the mapping threshold represents the value when the curve is infinitely close to or exceeds the vertical axis 1. The tone mapping curve represents the mapping relationship between the RGB color value of the HDR picture and the RGB color value of the LDR picture.

In step S202, tone mapping processing is performed on the test picture using the tone mapping curve to be tested to generate a processed picture corresponding to the tone mapping curve to be tested, which may include: if the current color information to be processed in the test picture is less than the mapping threshold of the tone mapping curve to be tested, the current color information to be processed is processed according to the tone mapping curve to be tested to generate a processed picture corresponding to the tone mapping curve to be tested.

This embodiment describes the principle of using a tone mapping curve to perform tone mapping processing. For the test picture, which is an HDR picture, there may be colors in the test picture whose brightness exceeds the display range of the LDR display, but there may also be some colors that can be displayed normally.

By setting the mapping threshold of the tone mapping curve, the colors in the test screen whose brightness exceeds the display range and the colors that do not exceed the display range can be divided into two ways for tone mapping. The ultimate goal is to map the color values whose brightness exceeds the display range to the color range of the LDR screen, and the color values whose brightness does not exceed the display range are mapped one by one. Finally, all color values in the mapped screen are within the color range that can be displayed by the LDR screen, so that they can be displayed on the LDR display.

In one embodiment, when the current color information to be processed in the test HDR picture is less than the mapping threshold of the tone mapping curve to be tested, since the RGB color value of the LDR picture corresponding to the test HDR picture does not exceed 1, that is, it is within the color range that the LDR picture can display normally, at this time, according to the tone mapping curve, it can be seen that when the color value of the HDR picture does not exceed the mapping threshold, the color value of the HDR picture corresponds one-to-one to the color value of the LDR picture, then the processed picture corresponding to the tone mapping curve to be tested can be generated according to the tone mapping curve and the current color information to be processed in the test HDR picture.

In this implementation, it is assumed that the tone mapping curve to be tested is a tone mapping curve with a mapping threshold of 1.25, and the functional relationship of the curve is: Then, when the current color information to be processed in the test screen is less than 1.25, the current color information to be processed can be substituted into the function relationship as the value of x, and the calculated y value is the color information in the processed screen corresponding to the color information to be processed in the test screen. The color information calculated here is RGB information, and its value is between 0-1, which does not exceed the display range of the LDR screen, so that the processed screen can be displayed on the monitor.

Optionally, in step S202, tone mapping processing is performed on the test picture using the tone mapping curve to be tested to generate a processed picture corresponding to the tone mapping curve to be tested, which may include: if the current color information to be processed in the test picture is greater than or equal to the mapping threshold of the tone mapping curve to be tested, then the current color information to be processed is processed according to a preset color threshold to generate a processed picture corresponding to the tone mapping curve to be tested.

Continuing with the tone mapping curve to be tested with a mapping threshold of 1.25 as an example, when the current to-be-processed color information in the test screen is greater than or equal to the mapping threshold of 1.25, the to-be-processed color information will be pulled back to the preset color threshold of 1, that is, all to-be-processed color information greater than or equal to the mapping threshold of 1.25 will be processed as 1, so as to remap the color information to between 0-1, and avoid the color information exceeding 1. When it exceeds 1, it exceeds the display range of the LDR screen and cannot be displayed.

The above is only an example of the tone mapping curve to be tested with a mapping threshold of 1.25. For any other tone mapping curve to be tested, the processing method is the same. For any tone mapping curve to be tested, when the current color information to be processed in the test screen is less than the mapping threshold, the curve function relationship corresponding to each tone mapping curve to be tested is used for color mapping. When the current color information to be processed is greater than or equal to the mapping threshold, the color information to be processed is mapped to 1.

In some embodiments, the tone mapping curve to be tested may have a mapping threshold of 1.25, a mapping threshold of 3, or a mapping threshold of 10, as long as the mapped image can be displayed on the LDR display without causing exposure. The size of the mapping threshold depends on the maximum brightness value of the tested HDR image, and can be controlled within a reasonable threshold range.

FIG4 is a schematic diagram of another tone mapping curve provided in an embodiment of the present application; the mapping threshold of the tone mapping curve shown in FIG4 is 3. Through the above method, assuming that the current color information to be processed in the test picture is 2, which exceeds 1, that is, exceeds the color display range of the LDR picture, and the color information to be processed is mapped using the tested tone mapping curve with a mapping threshold of 3 shown in FIG4, since the color information to be processed 2 does not exceed the mapping threshold 3, it can be determined according to the functional relationship of the mapping curve that when the color value of the HDR picture is 2, the corresponding color value of the LDR picture is 0.895, and 0.895 is between 0-1, which is within the color display range of the LDR picture, so that the processed picture can be displayed normally on the LDR display.

Optionally, in step S203, determining the color information of the processed image corresponding to the tone mapping curve to be tested may include: using a color extraction tool to extract the color information of each pixel in the processed image corresponding to the tone mapping curve to be tested, and obtaining the color information of the processed image corresponding to the tone mapping curve to be tested, the color information including: hue, saturation and brightness.

In some embodiments, the processed image corresponding to the tone mapping curve to be tested can be input into the color extraction tool to extract the color information of each pixel in the processed image. It is worth noting that the color information extracted here refers to HSV color information. When the tone mapping processing is performed above, it is all for RGB color processing. When the tone mapping curve to be tested is subsequently tested and analyzed, it is necessary to analyze it according to the HSV color information. In the range of 0-1, RGB information and HSV information have a one-to-one correspondence, so the corresponding HSV color information can be determined according to the calculated RGB information. For example: RBG color values are R: 0.895, G: 0.895, B: 0.895, and the corresponding HSV color values are H: 0, S: 0, V: 89.

FIG5 is a flow chart of another image tone mapping method provided in an embodiment of the present application; optionally, the standard test chart may include: a preset color chart and a preset grayscale chart.

In this embodiment, the standard test chart used may include: a preset color chart and a preset grayscale chart. Among them, the preset color chart may be an 18-color chart, and the preset grayscale chart may be a 33-grayscale chart. In actual applications, the preset color chart may also be a 19-color chart or a 20-color chart, etc., and the color classification in the color chart may be adaptively increased, and the preset grayscale chart may also be a 36-grayscale chart, etc. However, the 33-grayscale chart is a grayscale range that can be distinguished by the human eye. Beyond this range, the human eye cannot accurately distinguish and cannot perform effective testing, so the 33-grayscale chart is used in this embodiment.

The preset color card is used to illustrate the influence of the tone mapping curve to be tested on the color by comparing the offset ranges of hue, saturation and brightness.

The preset grayscale card is used to determine the change in picture contrast by measuring the offset range of brightness and contrast, checking the loss of details in bright and dark areas, and determining the degree of loss of picture details.

The 18-color card includes 18 base colors, and each base color is also marked with the corresponding H, S, and V values. The 33-grayscale card contains 33 grayscale colors, and each grayscale color is marked with the lightness V value.

In addition, in some embodiments, the standard test chart may also include a red, green, blue, white, gray and black chart, which is used to illustrate the influence of the tone mapping curve to be tested on the three primary colors and black, white and gray by measuring the offset range of hue, saturation and brightness.

In step S204, determining the style of the processed picture corresponding to the tone mapping curve to be tested according to the color information of the processed picture corresponding to the tone mapping curve to be tested and the standard test chart may include:

S501, determining the hue offset range, saturation offset range, and brightness offset range corresponding to the tone mapping curve to be tested, respectively, according to the hue value, saturation value, and brightness value of each pixel in the processed image corresponding to the tone mapping curve to be tested, and the hue value, saturation value, and brightness value of each reference color identified by a preset color card.

Optionally, the hue value, saturation value, and brightness value of each pixel in the processed image corresponding to the acquired tone mapping curve to be tested can be compared and analyzed with the hue value, saturation value, and brightness value of the reference color corresponding to each pixel in the 18-color card, so as to statistically analyze the hue offset range, saturation offset range, and brightness offset range of the processed image compared to the 18 color cards.

S502: Determine the hue, saturation and brightness analysis results of the tone mapping curve to be tested according to the hue offset range, the saturation offset range and the brightness offset range.

The hue analysis result of the tone mapping curve to be tested can be determined according to the hue offset range, the saturation analysis result of the tone mapping curve to be tested can be determined according to the saturation offset range, and the brightness analysis result of the tone mapping curve to be tested can be determined according to the brightness offset range.

S503: Determine the tone difference value corresponding to the tone mapping curve to be tested according to the brightness value of each pixel in the processed picture corresponding to the tone mapping curve to be tested and the brightness value of each grayscale color level identified by the preset grayscale card.

Similarly, the brightness value of each pixel in the processed image is compared with the brightness value of the grayscale color corresponding to each pixel in the 33 grayscale card, and the brightness difference is calculated to obtain the hue difference.

S504: Determine a contrast analysis result of the tone mapping curve to be tested according to the tone difference.

According to the tone difference, the contrast analysis result of the tone mapping curve to be tested can be obtained.

S505 , determining a processing picture style corresponding to the tone mapping curve to be tested according to the hue, saturation, brightness analysis results and the contrast analysis results.

By combining the hue analysis results, saturation analysis results, brightness analysis results and contrast analysis results, the processing picture style corresponding to the tested tone mapping curve can be determined. That is, the tone mapping picture style to which the tested tone mapping curve is applicable is comprehensively analyzed from the four aspects of hue, saturation, brightness and contrast of the processed picture obtained after the tested tone mapping curve performs tone mapping processing.

Optionally, in step S505, determining the processing picture style corresponding to the tone mapping curve to be tested according to the hue, saturation and brightness analysis results and the contrast analysis results may include: matching the hue, saturation and brightness analysis results and the contrast analysis results with each preset picture style according to the hue, saturation and brightness analysis results, the contrast analysis results and color attribute information of each preset picture style, and determining that the preset picture style that matches the hue, saturation and brightness analysis results and the contrast analysis results is the processing picture style corresponding to the tone mapping curve to be tested.

Usually, different picture styles correspond to different color attributes, that is, the style of the picture is determined by the color attributes of the picture, and the color attributes here can include but are not limited to the color hue, saturation, brightness, contrast, tone, etc., and the picture styles produced by different color attributes are also different. For example: the movie style is generally moderate in color, low in saturation, low in brightness, and low in contrast. The realistic style is generally small in color, moderate in saturation, moderate in brightness, and moderate in contrast. The cartoon style is generally high in color, high in saturation, high in brightness, and high in contrast.

Based on this, the hue, saturation, brightness analysis results, and contrast analysis results corresponding to the tone mapping curve to be tested obtained above can be matched with the color attribute information of each preset picture style, and the preset picture style corresponding to the matched tone mapping curve to be tested can be determined as the processed picture style corresponding to the tone mapping curve to be tested.

The following is an explanation of the hue, saturation, brightness analysis results and contrast analysis results using some data examples:

The following Table 1 is a data comparison result of analyzing hue, saturation and brightness using 18 color cards, wherein the tone mapping curves to be tested include: a first tone mapping curve (mapping threshold is 5), a second tone mapping curve (mapping threshold is 3) and a third tone mapping curve (mapping threshold is 1.25). In practical applications, all the tone mapping curves to be tested are analyzed in the following manner.

Table 1

Table 2 below shows the data comparison results of color tone analysis using a 33-grayscale card:

Table 2

Therefore, through the above analysis, it can be concluded that the first tone mapping curve is suitable for processing pictures with medium color cast, low saturation, low brightness and low contrast styles; the second tone mapping curve is suitable for processing pictures with low color cast, medium saturation, medium brightness and medium contrast styles; the third tone mapping curve is suitable for processing pictures with high color cast, high saturation, high brightness and high contrast styles.

Assume that the preset picture styles include: movie style, realistic style and cartoon style. Movie style generally has moderate color, low saturation, low brightness and low contrast; realistic style generally has small color, moderate saturation, moderate brightness and moderate contrast; cartoon style generally has high color, high saturation, high brightness and high contrast.

Then, through matching, it can be determined that the processed image of the first tone mapping curve presents a medium color cast, low saturation, low brightness, and low contrast image effect, and the corresponding processed image style can be a movie style. The processed image of the second tone mapping curve presents a low color cast, medium saturation, medium brightness, and medium contrast image effect, which is closer to the true color restoration, and the corresponding processed image style can be a realistic style. The processed image of the third tone mapping curve presents a high color cast, high saturation, high brightness, and high contrast image effect, and there is a certain loss of details in the bright part, and the corresponding processed image style can be a cartoon style.

Of course, this embodiment only lists three tone mapping curves and three preset picture styles. In actual applications, all tone mapping curves to be tested can be tested using this method, and the preset picture styles are not limited to those listed in this solution, so that the processing picture style corresponding to any tone mapping curve to be tested can be determined.

Optionally, in step S103, tone mapping is performed on the color information of the first picture using a target tone mapping curve to obtain color information of the second picture corresponding to the first picture, which may include: using the target tone mapping curve to perform tone mapping on the color information of each pixel in the first picture to obtain color information of each pixel in the second picture corresponding to the first picture to be processed.

Optionally, using a tone mapping curve to perform tone mapping processing on the first picture to be processed can be to map the color information of each pixel in the first picture using the tone mapping curve to obtain the color information of each pixel after mapping, and the mapped color information can be the color information of the second picture to be converted from the first picture, so that the second picture can be generated according to the color information of each pixel after mapping, that is, the HDR picture to be processed is converted into an LDR picture, and the LDR picture is displayed on the display.

In summary, the image tone mapping method provided in this embodiment, when converting an HDR picture to an LDR picture, will call the tone mapping curve corresponding to the target picture style according to the target picture style to which the HDR picture is to be mapped, and perform tone mapping processing, so that the display effect of the LDR picture obtained after mapping is better. In view of the different picture style processing requirements of users, a tone mapping curve matching the picture style can be used to perform tone mapping processing, avoiding the problem that different picture styles correspond to the same tone mapping curve, and the LDR picture effect obtained after tone mapping is poor due to the single and fixed tone mapping curve. And compared with the method of manually adjusting the tone mapping curve based on experience and visual observation, this scheme establishes a mapping relationship between the picture style and the tone mapping curve based on objective standards, so that the processing result obtained after tone mapping processing using the tone mapping curve corresponding to the picture style is more convincing, and the quality of the processing result has a measurement standard, avoiding the problem that the quality of the processing result cannot be measured due to relying on subjective consciousness.

The following describes the apparatus, device, storage medium, etc. used to execute the image tone mapping method provided in this application. The specific implementation process and technical effects are described above and will not be repeated below.

FIG6 is a schematic diagram of an image tone mapping device provided in an embodiment of the present application. The functions implemented by the image tone mapping device correspond to the steps performed by the above method. The device can be understood as the above processing device. As shown in FIG6, the device may include: an acquisition module 610, a determination module 620, a processing module 630, and a generation module 640;

An acquisition module 610 is used to acquire color information of a first picture to be processed, where the first picture is a high dynamic range picture;

A determination module 620 is used to determine a target picture style of a second picture to be mapped from the first picture, and a target tone mapping curve corresponding to the target picture style; the second picture is a low dynamic range picture;

A processing module 630 is used to perform tone mapping processing on the color information of the first picture using a target tone mapping curve to obtain color information of the second picture corresponding to the first picture;

The generating module 640 is used to generate a second picture according to the color information of the second picture, and the picture style of the second picture is the target picture style.

Optionally, the acquisition module 610 is further used to acquire a plurality of test pictures, where the test pictures are high dynamic range pictures;

The generating module 640 is further used to perform tone mapping processing on the test pictures respectively using the tone mapping curve to be tested, and generate a processed picture corresponding to the tone mapping curve to be tested;

The determination module 620 is further used to determine the color information of the processed picture corresponding to the tone mapping curve to be tested;

The determination module 620 is also used to determine the processed picture style corresponding to the tone mapping curve to be tested according to the color information of the processed picture corresponding to the tone mapping curve to be tested and the standard test chart, and establish a mapping relationship between the tone mapping curve to be tested and the corresponding processed picture style.

Optionally, the mapping thresholds of different tone mapping curves to be tested are different; a generation module 640 is specifically used to process the current color information to be processed according to the tone mapping curve to be tested if the current color information to be processed in the test picture is less than the mapping threshold of the tone mapping curve to be tested, and generate a processed picture corresponding to the tone mapping curve to be tested.

Optionally, the mapping thresholds of different tone mapping curves to be tested are different; a generation module 640 is specifically used to process the current color information to be processed according to a preset color threshold if the current color information to be processed in the test picture is greater than or equal to the mapping threshold of the tone mapping curve to be tested, and generate a processed picture corresponding to the tone mapping curve to be tested.

Optionally, the determination module 620 is specifically used to use a color extraction tool to extract the color information of each pixel in the processed picture corresponding to the tone mapping curve to be tested, and obtain the color information of the processed picture corresponding to the tone mapping curve to be tested, and the color information includes: hue, saturation and brightness.

Optionally, the standard test chart includes: a preset color chart and a preset grayscale chart; a determination module 620, specifically used to determine the hue offset range, saturation offset range and brightness offset range corresponding to the tone mapping curve to be tested, according to the hue value, saturation value and brightness value of each pixel point in the processed picture corresponding to the tone mapping curve to be tested and the hue value, saturation value and brightness value of each reference color identified by the preset color chart;

Determine the hue, saturation and brightness analysis results of the tone mapping curve to be tested according to the hue offset range, the saturation offset range and the brightness offset range;

Determine the tone difference value corresponding to the tone mapping curve to be tested according to the brightness value of each pixel in the processed picture corresponding to the tone mapping curve to be tested and the brightness value of each grayscale color level marked by the preset grayscale card;

Determine the contrast analysis result of the tone mapping curve to be tested according to the tone difference value;

According to the hue, saturation, brightness analysis results and contrast analysis results, the processing picture style corresponding to the tone mapping curve to be tested is determined.

Optionally, the determination module 620 is specifically used to match the hue, saturation and brightness analysis results, and the contrast analysis results with each preset picture style based on the hue, saturation and brightness analysis results, the contrast analysis results, and the color attribute information of each preset picture style, and determine that the preset picture style that matches the hue, saturation and brightness analysis results, and the contrast analysis results is the processed picture style corresponding to the tone mapping curve to be tested.

Optionally, the processing module 630 is specifically configured to perform tone mapping processing on color information of each pixel in the first picture by using a target tone mapping curve, so as to obtain color information of each pixel in the second picture corresponding to the first picture to be processed.

The above modules may be one or more integrated circuits configured to implement the above methods, such as one or more application specific integrated circuits (ASIC), or one or more digital singnal processors (DSP), or one or more field programmable gate arrays (FPGA). For another example, when a module is implemented in the form of a processing element scheduling program code, the processing element may be a general-purpose processor, such as a central processing unit (CPU) or other processors that can call program code. For another example, these modules may be integrated together and implemented in the form of a system-on-a-chip (SOC).

The above modules can be connected or communicated with each other via a wired connection or a wireless connection. The wired connection may include a metal cable, an optical cable, a hybrid cable, etc., or any combination thereof. The wireless connection may include a connection in the form of a LAN, a WAN, Bluetooth, a ZigBee, or NFC, or any combination thereof. Two or more modules may be combined into a single module, and any one module may be divided into two or more units. Those skilled in the art will clearly understand that for the convenience and brevity of description, the specific working process of the system and device described above can refer to the corresponding process in the method embodiment, and will not be repeated in this application.

FIG7 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application, including: a processor 801, a storage medium 802 and a bus 803, wherein the storage medium 802 stores machine-readable instructions executable by the processor 801. When the electronic device runs an image tone mapping method in the embodiment, the processor 801 communicates with the storage medium 802 via the bus 803, and the processor 801 executes the machine-readable instructions to perform the following steps:

Acquire color information of a first picture to be processed, where the first picture is a high dynamic range picture;

Determining a target picture style of a second picture to be mapped from the first picture, and a target tone mapping curve corresponding to the target picture style; the second picture is a low dynamic range picture;

Performing tone mapping processing on the color information of the first picture using the target tone mapping curve to obtain color information of the second picture corresponding to the first picture;

A second picture is generated according to the color information of the second picture, and the picture style of the second picture is the target picture style.

In a feasible implementation manner, before determining the target tone mapping curve corresponding to the target picture style, the processor 801 is further configured to: acquire a plurality of test pictures, where the test pictures are high dynamic range pictures;

Using the tone mapping curve to be tested to perform tone mapping processing on the test pictures respectively, and generate processed pictures corresponding to the tone mapping curve to be tested;

Determine the color information of the processed picture corresponding to the tone mapping curve to be tested;

According to the color information of the processed picture corresponding to the tested tone mapping curve and the standard test chart, the processed picture style corresponding to the tested tone mapping curve is determined, and a mapping relationship between the tested tone mapping curve and the corresponding processed picture style is established.

In a feasible implementation scheme, different mapping thresholds of tone mapping curves to be tested are different; when the processor 801 executes tone mapping processing on the test picture using the tone mapping curve to be tested to generate a processed picture corresponding to the tone mapping curve to be tested, it is specifically used for: if the current color information to be processed in the test picture is less than the mapping threshold of the tone mapping curve to be tested, the current color information to be processed is processed according to the tone mapping curve to be tested to generate a processed picture corresponding to the tone mapping curve to be tested.

In a feasible implementation scheme, different mapping thresholds of tone mapping curves to be tested are different; when the processor 801 executes tone mapping processing on the test picture using the tone mapping curve to be tested to generate a processed picture corresponding to the tone mapping curve to be tested, it is specifically used for: if the current color information to be processed in the test picture is greater than or equal to the mapping threshold of the tone mapping curve to be tested, the current color information to be processed is processed according to a preset color threshold to generate a processed picture corresponding to the tone mapping curve to be tested.

In a feasible implementation scheme, when the processor 801 determines the color information of the processed image corresponding to the tone mapping curve to be tested, it is specifically used to: use a color extraction tool to extract the color information of each pixel in the processed image corresponding to the tone mapping curve to be tested, and obtain the color information of the processed image corresponding to the tone mapping curve to be tested, and the color information includes: hue, saturation and brightness.

In a feasible implementation manner, the standard test chart includes: a preset color chart and a preset grayscale chart; when the processor 801 determines the processed picture style corresponding to the tone mapping curve to be tested according to the color information of the processed picture corresponding to the tone mapping curve to be tested and the standard test chart, it is specifically used to:

According to the hue value, saturation value, brightness value of each pixel in the processed picture corresponding to the tone mapping curve to be tested and the hue value, saturation value and brightness value of each reference color identified by the preset color card, respectively determine the hue offset range, saturation offset range and brightness offset range corresponding to the tone mapping curve to be tested;

Determine the hue, saturation and brightness analysis results of the tone mapping curve to be tested according to the hue offset range, the saturation offset range and the brightness offset range;

Determine the tone difference value corresponding to the tone mapping curve to be tested according to the brightness value of each pixel in the processed picture corresponding to the tone mapping curve to be tested and the brightness value of each grayscale color level marked by the preset grayscale card;

Determine the contrast analysis result of the tone mapping curve to be tested according to the tone difference value;

According to the hue, saturation, brightness analysis results and contrast analysis results, the processing picture style corresponding to the tone mapping curve to be tested is determined.

In a feasible implementation scheme, when the processor 801 determines the processing picture style corresponding to the tone mapping curve to be tested according to the hue, saturation and brightness analysis results and the contrast analysis results, it is specifically used to: match the hue, saturation and brightness analysis results, the contrast analysis results with each preset picture style according to the hue, saturation and brightness analysis results, the contrast analysis results and the color attribute information of each preset picture style, and determine that the preset picture style that matches the hue, saturation and brightness analysis results, and the contrast analysis results is the processing picture style corresponding to the tone mapping curve to be tested.

In a feasible implementation scheme, when the processor 801 executes tone mapping processing on the color information of the first picture using the target tone mapping curve to obtain the color information of the second picture corresponding to the first picture, it is specifically used to use the target tone mapping curve to perform tone mapping processing on the color information of each pixel in the first picture to obtain the color information of each pixel in the second picture corresponding to the first picture to be processed.

Through the above method, when the computer device obtains the target picture style of the HDR picture to be processed and the LDR picture to which the HDR picture is to be mapped, it will call the tone mapping curve corresponding to the target picture style to perform tone mapping according to the target picture style to which the HDR picture is to be mapped, so that the display effect of the LDR picture obtained after mapping is better. According to the different picture style processing requirements of users, the tone mapping process can be performed using a tone mapping curve that matches the picture style, avoiding the problem that different picture styles correspond to the same tone mapping curve, and the LDR picture effect obtained after tone mapping is poor due to the single and fixed tone mapping curve. And compared with the method of manually adjusting the tone mapping curve based on experience and visual observation, this scheme establishes a mapping relationship between the picture style and the tone mapping curve based on objective standards, so that the processing result obtained after the tone mapping process using the tone mapping curve corresponding to the picture style is more convincing, and the quality of the processing result has a measurement standard, avoiding the problem that the quality of the processing result cannot be measured due to relying on subjective consciousness.

Among them, the storage medium 802 stores program code, and when the program code is executed by the processor 801, the processor 801 executes various steps in the image tone mapping method according to various exemplary embodiments of the present application described in the above "Exemplary Method" section of this specification.

Processor 801 can be a general-purpose processor, such as a central processing unit (CPU), a digital signal processor (DigitalSignal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, and can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as a hardware processor to be executed, or a combination of hardware and software modules in the processor can be executed.

Storage medium 802, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer executable programs and modules. The memory may include at least one type of storage medium, such as flash memory, hard disk, multimedia card, card-type memory, random access memory (Random Access Memory, RAM), static random access memory (Static Random Access Memory, SRAM), programmable read-only memory (Programmable Read Only Memory, PROM), read-only memory (Read Only Memory, ROM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, EEPROM), magnetic memory, disk, optical disk, etc. The memory is any other medium that can be used to carry or store a desired program code in the form of an instruction or data structure and can be accessed by a computer, but is not limited thereto. The storage medium 802 in the embodiment of the present application can also be a circuit or any other device that can realize a storage function, for storing program instructions and/or data.

Optionally, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the processor performs the following steps:

Acquire color information of a first picture to be processed, where the first picture is a high dynamic range picture;

Determining a target picture style of a second picture to be mapped from the first picture, and a target tone mapping curve corresponding to the target picture style; the second picture is a low dynamic range picture;

Performing tone mapping processing on the color information of the first picture using the target tone mapping curve to obtain color information of the second picture corresponding to the first picture;

A second picture is generated according to the color information of the second picture, and the picture style of the second picture is the target picture style.

In a feasible implementation manner, before determining the target tone mapping curve corresponding to the target picture style, the processor 801 is further configured to: acquire a plurality of test pictures, where the test pictures are high dynamic range pictures;

Using the tone mapping curve to be tested to perform tone mapping processing on the test pictures respectively, and generate processed pictures corresponding to the tone mapping curve to be tested;

Determine the color information of the processed picture corresponding to the tone mapping curve to be tested;

According to the color information of the processed picture corresponding to the tested tone mapping curve and the standard test chart, the processed picture style corresponding to the tested tone mapping curve is determined, and a mapping relationship between the tested tone mapping curve and the corresponding processed picture style is established.

In a feasible implementation scheme, different mapping thresholds of tone mapping curves to be tested are different; when the processor 801 executes tone mapping processing on the test picture using the tone mapping curve to be tested to generate a processed picture corresponding to the tone mapping curve to be tested, it is specifically used for: if the current color information to be processed in the test picture is less than the mapping threshold of the tone mapping curve to be tested, the current color information to be processed is processed according to the tone mapping curve to be tested to generate a processed picture corresponding to the tone mapping curve to be tested.

In a feasible implementation scheme, different mapping thresholds of tone mapping curves to be tested are different; when the processor 801 executes tone mapping processing on the test picture using the tone mapping curve to be tested to generate a processed picture corresponding to the tone mapping curve to be tested, it is specifically used for: if the current color information to be processed in the test picture is greater than or equal to the mapping threshold of the tone mapping curve to be tested, the current color information to be processed is processed according to a preset color threshold to generate a processed picture corresponding to the tone mapping curve to be tested.

In a feasible implementation scheme, when the processor 801 determines the color information of the processed image corresponding to the tone mapping curve to be tested, it is specifically used to: use a color extraction tool to extract the color information of each pixel in the processed image corresponding to the tone mapping curve to be tested, and obtain the color information of the processed image corresponding to the tone mapping curve to be tested, and the color information includes: hue, saturation and brightness.

In a feasible implementation manner, the standard test chart includes: a preset color chart and a preset grayscale chart; when the processor 801 determines the processed picture style corresponding to the tone mapping curve to be tested according to the color information of the processed picture corresponding to the tone mapping curve to be tested and the standard test chart, it is specifically used to:

According to the hue value, saturation value, brightness value of each pixel in the processed picture corresponding to the tone mapping curve to be tested and the hue value, saturation value and brightness value of each reference color identified by the preset color card, respectively determine the hue offset range, saturation offset range and brightness offset range corresponding to the tone mapping curve to be tested;

Determine the hue, saturation and brightness analysis results of the tone mapping curve to be tested according to the hue offset range, the saturation offset range and the brightness offset range;

Determine the tone difference value corresponding to the tone mapping curve to be tested according to the brightness value of each pixel in the processed picture corresponding to the tone mapping curve to be tested and the brightness value of each grayscale color level marked by the preset grayscale card;

Determine the contrast analysis result of the tone mapping curve to be tested according to the tone difference value;

According to the hue, saturation, brightness analysis results and contrast analysis results, the processing picture style corresponding to the tone mapping curve to be tested is determined.

In a feasible implementation scheme, when the processor 801 determines the processing picture style corresponding to the tone mapping curve to be tested according to the hue, saturation and brightness analysis results and the contrast analysis results, it is specifically used to: match the hue, saturation and brightness analysis results and the contrast analysis results with each preset picture style according to the hue, saturation and brightness analysis results, the contrast analysis results and the color attribute information of each preset picture style, and determine that the preset picture style that matches the hue, saturation and brightness analysis results and the contrast analysis results is the processing picture style corresponding to the tone mapping curve to be tested.

In a feasible implementation scheme, when the processor 801 executes tone mapping processing on the color information of the first picture using the target tone mapping curve to obtain the color information of the second picture corresponding to the first picture, it is specifically used to use the target tone mapping curve to perform tone mapping processing on the color information of each pixel in the first picture to obtain the color information of each pixel in the second picture corresponding to the first picture to be processed.

Through the above method, when the computer device obtains the target picture style of the HDR picture to be processed and the LDR picture to be converted to by the HDR picture, it will call the tone mapping curve corresponding to the target picture style to perform tone mapping according to the target picture style to be mapped to the HDR picture, so that the display effect of the LDR picture obtained after mapping is better. According to the different picture style processing requirements of users, the tone mapping process can be performed using a tone mapping curve that matches the picture style, avoiding the problem that different picture styles correspond to the same tone mapping curve, and the LDR picture effect obtained after tone mapping is poor due to the single and fixed tone mapping curve. And compared with the method of manually adjusting the tone mapping curve based on experience and visual observation, this scheme establishes a mapping relationship between the picture style and the tone mapping curve based on objective standards, so that the processing result obtained after the tone mapping process using the tone mapping curve corresponding to the picture style is more convincing, and the quality of the processing result has a measurement standard, avoiding the problem that the quality of the processing result cannot be measured due to relying on subjective consciousness.

In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (English: processor) to perform some steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (English: Read-Only Memory, abbreviated: ROM), random access memory (English: Random Access Memory, abbreviated: RAM), disk or optical disk and other media that can store program codes.

Claims (11)

1. A method of tone mapping an image, comprising:

acquiring color information of a first picture to be processed, wherein the first picture is a high dynamic range picture;

determining a target picture style of a second picture to be mapped of the first picture and a target tone mapping curve corresponding to the target picture style; the second picture is a low dynamic range picture;

performing tone mapping processing on the color information of the first picture by adopting the target tone mapping curve to obtain the color information of a second picture corresponding to the first picture;

And generating the second picture according to the color information of the second picture, wherein the picture style of the second picture is the target picture style.

2. The method of claim 1, wherein prior to determining the target tone mapping curve corresponding to the target picture style, the method further comprises:

acquiring a plurality of test pictures, wherein the test pictures are high dynamic range pictures;

respectively carrying out tone mapping treatment on the test pictures by adopting tone mapping curves to be detected, and generating treated pictures corresponding to the tone mapping curves to be detected;

determining color information of a processed picture corresponding to a tone mapping curve to be detected;

and determining the processing picture style corresponding to the tone mapping curve to be detected according to the color information of the processed picture corresponding to the tone mapping curve to be detected and the standard test chart, and establishing a mapping relation between the tone mapping curve to be detected and the corresponding processing picture style.

3. The method according to claim 2, wherein the mapping thresholds of different tone mapping curves to be measured are different; the tone mapping process is performed on the test picture by using the tone mapping curve to be tested, and a processed picture corresponding to the tone mapping curve to be tested is generated, which comprises the following steps:

And if the current color information to be processed in the test picture is smaller than the mapping threshold value of the tone mapping curve to be detected, processing the current color information to be processed according to the tone mapping curve to be detected, and generating a processed picture corresponding to the tone mapping curve to be detected.

4. The method according to claim 2, wherein the mapping thresholds of different tone mapping curves to be measured are different; the tone mapping process is performed on the test picture by using the tone mapping curve to be tested, and a processed picture corresponding to the tone mapping curve to be tested is generated, which comprises the following steps:

and if the current color information to be processed in the test picture is greater than or equal to the mapping threshold value of the tone mapping curve to be detected, processing the current color information to be processed according to a preset color threshold value to generate a processed picture corresponding to the tone mapping curve to be detected.

5. The method according to claim 2, wherein determining color information of the processed picture corresponding to the tone mapping curve to be measured comprises:

extracting color information of each pixel point in the processed picture corresponding to the tone mapping curve to be detected by adopting a color extraction tool to obtain the color information of the processed picture corresponding to the tone mapping curve to be detected, wherein the color information comprises: hue, saturation, and brightness.

6. The method of claim 2, wherein the standard test card comprises: presetting a color card and a gray-scale card; the determining the style of the processed picture corresponding to the tone mapping curve to be detected according to the color information of the processed picture corresponding to the tone mapping curve to be detected and the standard test chart card comprises the following steps:

respectively determining a hue shift range, a saturation shift range and a brightness shift range corresponding to the tone mapping curve to be detected according to the hue value, the saturation value and the brightness value of each pixel point in the processed picture corresponding to the tone mapping curve to be detected and the hue value, the saturation value and the brightness value of each reference color marked by the preset color card;

determining the hue, saturation and brightness analysis results of the tone mapping curve to be measured according to the hue shift range, the saturation shift range and the brightness shift range;

determining a tone difference value corresponding to a tone mapping curve to be detected according to the brightness value of each pixel point in the processed picture corresponding to the tone mapping curve to be detected and the brightness value of each gray level color marked by the preset gray level card;

determining a contrast analysis result of the tone mapping curve to be detected according to the tone difference value;

And determining the processing picture style corresponding to the tone mapping curve to be detected according to the hue, the saturation, the brightness analysis result and the contrast analysis result.

7. The method of claim 6, wherein determining a processing picture style corresponding to the tone mapping curve to be measured based on the hue, saturation, and brightness analysis results and the contrast analysis results comprises:

and matching the hue, the saturation and the brightness analysis result with each preset picture style according to the hue, the saturation and the brightness analysis result, the contrast analysis result and the color attribute information of each preset picture style, and determining that the preset picture style matched with the hue, the saturation and the brightness analysis result and the contrast analysis result is the processing picture style corresponding to the tone mapping curve to be detected.

8. The method of claim 1, wherein performing tone mapping processing on the color information of the first picture using the target tone mapping curve to obtain color information of a second picture corresponding to the first picture, comprises:

And performing tone mapping processing on the color information of each pixel in the first picture by adopting the target tone mapping curve to obtain the color information of each pixel in a second picture corresponding to the first picture to be processed.

9. An image tone mapping apparatus, comprising: the device comprises an acquisition module, a determination module, a processing module and a generation module;

the acquisition module is used for acquiring color information of a first picture to be processed, wherein the first picture is a high dynamic range picture;

the determining module is configured to determine a target picture style of the second picture to be mapped by the first picture, and a target tone mapping curve corresponding to the target picture style; the second picture is a low dynamic range picture;

the processing module is used for performing tone mapping processing on the color information of the first picture by adopting the target tone mapping curve to obtain the color information of a second picture corresponding to the first picture;

the generating module is configured to generate the second picture according to color information of the second picture, where a picture style of the second picture is the target picture style.

10. An electronic device, comprising: a processor, a storage medium and a bus, the storage medium storing program instructions executable by the processor, the processor and the storage medium communicating over the bus when the electronic device is running, the processor executing the program instructions to perform the image tone mapping method of any one of claims 1 to 8.

11. A computer readable storage medium, characterized in that the storage medium has stored thereon a computer program which, when executed by a processor, performs the image tone mapping method according to any of claims 1 to 8.