TWI887598B - Projecting correction method and projecting correction system - Google Patents

Abstract

A projecting correction method and a projecting correction system are provided. In the method, a captured image is obtained, where the image content of the captured image includes a projected image; first position information of the projected image is obtained from the captured image; the captured image is loaded into an user interface (UI), where the UI shows an auxiliary area based on the first position information; a definition operation corresponding to second position information of a target area on the UI is used for adjusting the auxiliary area to the target area; an image adjustment command is generated according to the position difference between the first position information and the second position information, where the image adjustment command is used for correcting the projected image. Accordingly, the efficiency and accuracy of projecting correction could be improved.

Description

Projection correction method and projection correction system

The present invention relates to a projection technology, and in particular to a projection correction method and a projection correction system.

When setting up a projector, it is inevitable to adjust the projected image such as scaling, focusing, projection tilt, horizontal/vertical keystone, etc. according to the environment and space. Although current technology can automatically calibrate the projected image, the automatic calibration results in some application scenarios do not meet the user's expectations. In addition, the user cannot modify the parameters required for calibration during the automatic calibration process, and the projector cannot evaluate the calibration results. It is even necessary to wait for the automatic calibration to be completed before manually fine-tuning the projected image.

For example, FIG. 1A and FIG. 1B are schematic diagrams of known projection automatic correction. Referring to FIG. 1A , the shape of the projection image PI on the projection screen PP is a trapezoid. Referring to FIG. 1B , the automatic correction technology can correct the projection image PI from a trapezoid to a rectangle. However, the user hopes that the expected range EP of the projection image PI is in the middle of the projection screen PP. Therefore, the user needs to manually adjust the projection settings of the projector via a remote control or on-board buttons to shift the projection image PI upward.

On the other hand, the wall where the projected image is located is not necessarily an ideal plane. When projecting on a non-planar wall, the result of automatic correction is usually difficult to meet expectations. For example, Figures 2A and 2B are schematic diagrams of projection on different walls. Please refer to Figure 2A. If the projection is on a flat wall, the automatic correction technology can correct the shape of the projected image PI of the projector P to a rectangle. However, please refer to Figure 2B. If the projection is on a corner of the wall, manual correction can correct the projected image PI of the projector P to the expected shape.

Furthermore, in order to achieve the desired projection image, the user usually has to manually test the final parameters. When the projector is used next time, the previous parameters are not retained and the projection image still needs to be recalibrated, which is inconvenient for the user.

The "prior art" section is only used to help understand the content of the present invention. Therefore, the content disclosed in the "prior art" section may contain some content that does not constitute the common knowledge of the person skilled in the art. The content disclosed in the "prior art" section does not mean that the content or the problem to be solved by one or more embodiments of the present invention has been known or recognized by the person skilled in the art before the application of the present invention.

The embodiments of the present invention provide a projection correction method and a projection correction system, which can provide correction auxiliary information on a user interface to improve the correction convenience and accuracy of the projection image.

Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

To achieve one or part or all of the above-mentioned purposes or other purposes, a projection correction method proposed in an embodiment of the present invention includes: obtaining a captured image, wherein the image content of the captured image includes a projection image; obtaining first position information of the projection image from the captured image; loading the captured image into a user interface, wherein an auxiliary range based on the first position information is presented through the user interface; receiving a definition operation of second position information corresponding to a target range on the user interface, wherein the definition operation is used to adjust the auxiliary range to the target range; generating an image adjustment instruction based on the position difference between the first position information and the second position information, wherein the image adjustment instruction is used to change the projection image.

In one embodiment of the present invention, the step of obtaining the first position information of the projection image from the captured image includes: determining at least one contour position of the projection image contour in the captured image; using the contour position as the first position information, wherein an auxiliary range is generated based on the contour position.

In an embodiment of the present invention, before the step of obtaining the first position information of the projection image from the captured image, the method further includes: performing at least one of the following image processing on the captured image: perspective transformation; grayscale processing; noise reduction processing.

In one embodiment of the present invention, the step of loading the captured image into the user interface includes: using the captured image as a first layer; using the user interface to use the auxiliary range as a second layer and overlaying it on the first layer having the captured image. The projection correction method further includes: in response to receiving the definition operation, overlaying the target range on the second layer through the user interface.

In one embodiment of the present invention, the outline of the projection image is a polygon, and the projection correction method further includes: determining the geometric characteristics of the polygon, wherein the user interface further presents the geometric characteristics of the projection image, and the geometric characteristics include at least one of length, angle and area.

In one embodiment of the present invention, the step of loading the captured image into the user interface includes: defining a critical range according to an adjustment parameter, wherein the adjustment parameter is a critical setting corresponding to at least one of a shape distortion correction range value and a screen displacement range value of a projection device; presenting the critical range on the user interface; and limiting the target range to be less than or equal to the critical range.

In one embodiment of the present invention, the step of loading the captured image into the user interface includes: defining a layer structure of the user interface, wherein the layer structure is, from low to high, captured image, auxiliary range, geometric characteristics of the projected image, critical range, and target range.

In one embodiment of the present invention, the first position information includes at least one auxiliary vertex position of the auxiliary range, the second position information includes at least one target vertex position of the target range, and the step of generating an image adjustment instruction based on the position difference between the first position information and the second position information includes: determining the displacement from the auxiliary vertex position to the corresponding target vertex position, wherein the image adjustment instruction includes the displacement.

In one embodiment of the present invention, the step of loading the captured image into the user interface includes: displaying a plurality of grids in an auxiliary range, wherein the shapes of those grids correspond to the outline of the projected image.

In one embodiment of the present invention, the step of generating an image adjustment instruction based on the position difference between the first position information and the second position information includes: determining the displacement of the nodes corresponding to the contour in the grid according to the target range, wherein the image adjustment instruction includes the displacement.

To achieve one or part or all of the above purposes or other purposes, a projection correction system proposed in an embodiment of the present invention includes: a computing device and a projection device. The projection device is communicatively connected to the computing device and is used to project a projection image. The computing device includes: a display, an input device and a processor. The display is used to display a user interface. The input device is used to receive user operations. The processor is coupled to the display and the input device, and is configured to: obtain a captured image, wherein the image content of the captured image includes a projection image; obtain first position information of the projection image from the captured image; load the captured image into a user interface, wherein an auxiliary range based on the first position information is presented through the user interface; receive a definition operation of second position information corresponding to a target range on the user interface through the input device, wherein the definition operation is used to adjust the auxiliary range to the target range; generate an image adjustment instruction based on a position difference between the first position information and the second position information, wherein the image adjustment instruction is used to change the projection image.

In one embodiment of the present invention, the projection correction system further includes an image capture device. The image capture device is communicatively connected to the computing device and is used to generate a captured image.

Based on the above, the embodiment of the present invention has at least one of the following advantages or effects: wherein the user interface presents an auxiliary range based on the captured image and receives a definition operation of the target range. In addition, the projected image is adjusted according to the position difference between the auxiliary range and the target range. In this way, a convenient adjustment operation interface and calibration reference can be provided to the user, thereby improving the convenience of the construction process of the projection device and the calibration accuracy, and also improving the adjustment efficiency of the user.

In order to make the above features and advantages of the present invention more clearly understood, embodiments are specifically cited below and described in detail with reference to the accompanying drawings.

The above-mentioned and other technical contents, features and effects of the present invention will be clearly presented in the detailed description of a preferred embodiment in conjunction with the reference drawings below. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and are not used to limit the present invention. In addition, the word "coupling" mentioned in the following embodiments may refer to any direct or indirect connection means. In addition, the word "signal" may refer to at least one current, voltage, charge, temperature, data, electromagnetic wave or any other one or more signals.

FIG3 is a block diagram of a projection correction system 1 according to an embodiment of the present invention. Referring to FIG3 , the projection correction system 1 includes a computing device 10 , an image capturing device 30 , and a projection device 50 .

The computing device 10 may be a smart phone, a tablet computer, a computer, a server, a wearable device, a smart assistant device, a smart home appliance, or other electronic devices with computing functions.

The computing device 10 includes a display 11 , an input device 12 , a communication transceiver 13 , a memory 14 , and a processor 15 .

The display 11 may be a liquid crystal display (LCD), a light emitting diode (LED) display or an organic light emitting diode (OLED) display. In one embodiment, the display 11 is used to display images. For example, the display 11 displays images of a user interface.

The input device 12 may be a mouse, a keyboard, a touch panel or a button. In one embodiment, the input device 12 is used to receive an input operation of a user (hereinafter referred to as a user operation), such as a press, click or slide operation.

The communication transceiver 13 may be a transceiver circuit supporting mobile network, Bluetooth, Wi-Fi or other communication technologies, or may be a transmission interface supporting USB, UART, or other buses. In one embodiment, the communication transceiver 13 is used to transmit or receive data with an external device (e.g., the image capture device 30 and the projection device 50). In another embodiment, the communication transceiver 13 is used to directly connect the image capture device 30 and the projection device 50.

The memory 14 can be any type of fixed or removable random access memory (RAM), read only memory (ROM), flash memory, traditional hard disk drive (HDD), solid-state drive (SSD) or similar components. In one embodiment, the memory 14 is used to store program code, software modules (e.g., control module 141, image processing module 142 and/or user interface 143), data (e.g., images, location information, auxiliary information, instructions or geometric characteristics) or files, and its details will be described in detail in subsequent embodiments.

The processor 15 is coupled to the display 11, the input device 12, the communication transceiver 13 and the memory 14. The processor 15 can be a central processing unit (CPU), or other programmable general-purpose or special-purpose microprocessor (Microprocessor), digital signal processor (Digital Signal Processor, DSP), programmable controller, application-specific integrated circuit (Application-Specific Integrated Circuit, ASIC) or other similar components or combinations of the above components. In one embodiment, the processor 15 is used to execute all or part of the operations of the computing device 10. In one embodiment, the processor 15 can load and execute the program code, software module, file and/or data stored in the memory 14 to implement the method flow of the embodiment of the present invention.

The image capture device 30 can be a camera, a video camera or a device with an image capture function. The image capture device 30 is communicatively connected to the computing device 10. In one embodiment, the image capture device 30 is used to generate a captured image.

The projection device 50 can be a device of digital light processing (DLP), liquid crystal display (LCD), light emitting diode (LED) or other projection imaging technology. The projection device 50 can be an independent projector, or a projection optical device built into any electronic device. Among them, the projection device 50 can be implemented by any hardware that is well known to those of ordinary skill in the art and can perform image projection operations, without fixed restrictions. The projection device 50 is communicatively connected to the computing device 10. In one embodiment, the projection device 50 is used to project a projection image.

In one embodiment, at least two of the computing device 10, the image capture device 30, and the projection device 50 may be integrated into an independent device. In another embodiment, part or all of the functions of the computing device 10 may also be implemented in the image capture device 30 and/or the projection device 50.

Hereinafter, the method described in the embodiment of the present invention will be described with reference to various devices, components, and modules in the projection correction system 1. The various processes of the method can be adjusted according to the implementation situation, and are not limited thereto.

FIG4 is a flow chart of a projection correction method according to an embodiment of the present invention. Referring to FIG4 , the image processing module 142 obtains a captured image (step S410). Specifically, the processor 15 of the computing device 10 executes the image processing module 142 stored in the memory 14. The projection device 50 projects a projection image. This projection image can be a test image. For example, a monochrome image, a screen image, or a photo, but not limited to this. The image capture device 30 shoots the projection image projected by the projection device 50 and generates a captured image accordingly. The image processing module 142 of the computing device 10 obtains the captured image from the image capture device 30 through the communication transceiver 13. The captured content of the captured image at least includes the projection image, and may further include the projection environment (eg, a wall, a curtain or a ceiling).

For example, Fig. 5 is a schematic diagram of a captured image according to an embodiment of the present invention. Referring to Fig. 5, the captured content of the captured image includes the wall W and the projection image PI2.

Please refer to FIG. 4 , the image processing module 142 obtains the first position information of the projection image from the captured image (step S420). Specifically, the projection image is projected onto one or more objects (walls, curtains or ceilings) in a space (projection environment) to form an image, and the projection image occupies a certain range in the space. This first position information is related to the position of the projection image in the space where the image is captured. In addition, this first position information reflects the geometric structure of the object onto which the projection image is projected. For example, a plane or a polyhedron.

The extent of the projected image in the space of the captured image can be defined by the outline of the projected image. In one embodiment, the image processing module 142 can determine one or more outline positions of the outline of the projected image in the captured image. For example, contour recognition can be performed and the position of the identified contour can be determined through an inference model trained by a machine learning algorithm (e.g., YOLO (You only look once), Region Based Convolutional Neural Networks (R-CNN), or Fast R-CNN) or an algorithm based on feature matching (e.g., feature matching of Histogram of Oriented Gradient (HOG), Scale-Invariant Feature Transform (SIFT), Harr, or Speeded Up Robust Features (SURF)). The image processing module 142 can use one or more contour positions as the first position information. That is, the first position information includes the contour position. The context position information can be defined by image coordinates, spatial coordinates, or relative positions.

Next, the image processing module 142 may generate an auxiliary range based on one or more contour positions, and may present the auxiliary range based on the first position information through the user interface 143, and the display 11 displays the user interface 143. The contour position is located on the boundary of the auxiliary range. In other words, the boundary of the auxiliary range is the contour of the projected image. The image processing module 142 may connect these contour positions according to the relative position relationship and construct the auxiliary range accordingly.

In another embodiment, the image processing module 142 may use the position of any point or area in the range occupied by the projection image as the first position information.

In one embodiment, before the step of obtaining the first position information of the projection image from the captured image, the image processing module 142 may also perform one or more of the following operations. FIG. 6 is a flow chart of image analysis according to an embodiment of the present invention. Referring to FIG. 6 , the image processing module 142 may perform at least one of the following image processing on the captured image: perspective transformation, grayscale processing, and noise reduction processing (step S610). Perspective transformation is to project the image onto another viewing plane. In some application scenarios, the plane where the projection image is located is not necessarily facing the lens of the image capture device 30, and the perspective transformation can convert the projection image to face the lens of the image capture device 30. Grayscale processing converts color captured images into grayscale images, which may help with subsequent contour recognition. One of the purposes of noise reduction processing is to remove noise from captured images, thereby retaining important details in the captured images, which in turn helps with subsequent object recognition.

In one embodiment, the outline of the projected image is a polygon. For example, a quadrilateral is formed on the wall surface (plane) as shown in FIG. 2A or a hexagon is formed on the wall corner (non-plane) as shown in FIG. 2B. The image processing module 142 can determine these outline positions of the projected image in the captured image (step S620). These outline positions can be the positions of the vertices of the polygon, that is, the auxiliary vertex positions of the vertices of the auxiliary range. In general, if the auxiliary vertex positions and the relative position relationship are known, the appearance of the polygon (that is, the auxiliary range) can be inferred. The image processing module 142 can use these auxiliary vertex positions as the first position information of the projected image, so that the first position information includes one or more auxiliary vertex positions of the auxiliary range.

The image processing module 142 can determine the geometric characteristics of the outline of the projection image in the captured image (step S630). If the outline of the projection image is a polygon, for example, the geometric characteristics include at least one of length, angle, and area. Taking a quadrilateral as an example, FIG. 7 is a schematic diagram of geometric characteristics according to an embodiment of the present invention. Referring to FIG. 7, the outline of the projection image PI2 is a trapezoid, and its geometric characteristics are the length L of the side, the angle D of the four corners, and the area of the trapezoid.

The image processing module 142 may perform coordinate system or unit conversion (step S640). For example, the coordinates may be converted from the image coordinate system to the coordinate system of the real world, or from the coordinate system of the image capture device 30 to the coordinate system of the projection device 50. For another example, the length unit may be converted from the number of pixels to centimeters, meters or other length measurement units.

Referring to FIG. 4 , the processor 15 loads the captured image into the user interface 143 (step S430 ). That is, the user interface 143 presents the captured image. The display 11 displays the user interface 143 for the user to view and perform subsequent interface operations.

In addition, the processor 15 also presents an auxiliary range based on the first position information through the user interface 143. As described above, the boundary of the auxiliary range is the outline of the projected image. The processor 15 can highlight the auxiliary range on the user interface 143. For example, a thick line, bright color and/or flashing.

The processor 15 of the computing device 10 receives a definition operation corresponding to the second position information of the target range on the user interface 143 through the input device 12 (step S440). Specifically, the target range is related to the outline and position of the projection image desired by the user. The definition operation is used to adjust the auxiliary range to the target range. The second position information includes the position on the boundary of the target range. For example, the trajectory corresponding to the user's sliding operation forms the target range. For another example, the destination position corresponding to the user's dragging operation forms the boundary of the target range. For another example, the new line corresponding to the user's adding operation forms the edge of the target range. In other words, the definition operation is to draw or construct the outline of the target range on the user interface 143. Since the user interface 143 also presents the auxiliary range, the definition operation also defines the position of the target range relative to the auxiliary range (or the projected image in the captured image).

In addition, since the user interface 143 also presents the captured image, it can assist the user in confirming whether the target range is defined at an unexpected location in the real space (projected environment), such as outside the screen, at a corner, or on a curved surface.

In one embodiment, the processor 15 uses the captured image as the first layer and the auxiliary range as the second layer through the user interface 143 and overlaps the first layer with the captured image. In other words, the first layer is located at the bottom layer and the second layer is overlapped on the first layer; the captured image is located at the bottom layer and the auxiliary range is overlapped on the captured image. In this way, the viewer can understand the outline of the projected image.

In addition, in response to the input device 12 receiving the definition operation of the target range, the processor 15 can overlay the target range on the second layer through the user interface 143. That is, the user displays (e.g., slides) the target range through the user interface 143, and the processor 15 presents the target range on the third layer or a higher layer, and the third layer is overlaid on the second layer. In addition, the processor 15 can highlight the target range in a different way from presenting the auxiliary range, so that the viewer can distinguish between the auxiliary range and the target range.

In one embodiment, the processor 15 may define a critical range based on an adjustment parameter. This adjustment parameter is a critical setting corresponding to at least one of a shape distortion correction range value and a picture displacement range value of the projection device 50. If the projection device 50 supports a keystone correction function, the processor 15 may obtain a parameter value that can form a maximum polygon from a plurality of keystone correction parameter values (i.e., a critical setting of a shape distortion correction range value). If the projection device 50 supports a lens shift function, the processor 15 may obtain a parameter value that can form a maximum polygon from a plurality of lens shift parameter values (i.e., a critical setting of a picture displacement range value). The processor 15 may determine a critical range based on the parameter value that forms the maximum range supported by the projection device 50. In other words, the critical range is the maximum range that the projection device 50 can form when projecting an image onto an object based on its internal mechanism and optical design.

The processor 15 may present the critical range on the user interface 143. In one embodiment, the processor 15 may overlay the critical range on the third layer through the user interface 143. That is, the critical range is located on the fourth layer, and the fourth layer is overlaid on the third layer. In addition, the processor 15 may highlight the critical range in a manner different from presenting the auxiliary range and the target range, so that the viewer can easily distinguish between the auxiliary range, the target range and the critical range.

The processor 15 can also limit the target range to be smaller than or equal to the critical range, so that the boundary of the target range is located within or above the boundary of the critical range. Taking a rectangle as an example, the length and width need to be located within or above the boundary of the critical range. The limiting method is, for example, if the target range is larger than the critical range, the processor 15 prompts a warning message through the display 11. For another example, if the position of the definition operation on the user interface 143 exceeds the critical range, the processor 15 hides the track that exceeds the critical range through the display 11. In this way, the user can be prompted to redefine the target range.

In one embodiment, the processor 15 may define a layer structure of the user interface 143. The layer structure is an overlapping relationship of different layers in the user interface 143. For example, FIG8 is a schematic diagram of the layer structure of the user interface 143 according to an embodiment of the present invention. Referring to FIG8, the layer structure is sequentially from low (i.e., bottom layer) to high (i.e., top layer) as captured image CI, auxiliary range AR, geometric characteristics of projected image GC, critical range LR, and target range TR. That is, the captured image CI is located in the first layer L1 (i.e., the bottom layer), the auxiliary range AR (which may be accompanied by coordinate coefficients) is located in the second layer L2, the geometric characteristics of the projected image GC are located in the third layer L3, the critical range LR (which may be accompanied by auxiliary markings and drawing tools) is located in the fourth layer L4, and the target range TR is located in the fifth layer L5 (i.e., the top layer).

FIG9 is a schematic diagram of a user interface UI1 according to an embodiment of the present invention. Referring to FIG9 , the user interface UI1 presents overlapping results of different layers. In addition to presenting the captured image, the user interface UI1 also presents the auxiliary range AR, the critical range LR, the target range TR, and the geometric characteristics GC of the outline of the projected image. In addition, tool options TB such as drawing tools (used to provide users with the ability to draw the target range TR through the user interface UI1), parameter data (used to switch or enable or disable the presentation of the geometric characteristics GC), and control (used to trigger image control) buttons may be located in the same or different layers as the target range TR.

It should be noted that in other implementations, the layer structure may have other changes. For example, the geometric characteristic GC and the critical range LR of the projected image are located in the same layer. For another example, the layer of the geometric characteristic GC is cancelled.

Referring to FIG. 4 , the control module 141 generates an image adjustment instruction according to the position difference between the first position information and the second position information (step S450). Specifically, the processor 15 of the computing device 10 executes the control module 141 stored in the memory 14. The image adjustment instruction is transmitted to the projection device 50 through the control module 141, so that the projection device 50 changes the outline and/or position of the projection image according to the image adjustment instruction, and it is expected that the outline of the projection image is aligned with the boundary of the target range. The position difference is the position difference between the boundary of the target range and the boundary of the auxiliary range.

In one embodiment, the first position information includes one or more auxiliary vertex positions of the auxiliary range (i.e., positions of the vertices of the auxiliary range), and the second position information includes one or more target vertex positions of the target range (i.e., positions of the vertices of the target range). The control module 141 may determine a displacement from the auxiliary vertex position to the corresponding target vertex position, and the image adjustment instruction includes the displacement.

Taking FIG. 9 as an example, the control module 141 can generate an image adjustment instruction according to the displacement TP1 from the auxiliary vertex position TAP of the auxiliary range AR to the corresponding target vertex position AAP of the target range TR. The control module 141 transmits the image adjustment instruction to the projection device 50 through the communication transceiver 13 of the computing device 10. The projection device 50 can move the vertex corresponding to the auxiliary vertex position TAP to the vertex corresponding to the target vertex position AAP according to the image adjustment instruction. The displacement of the remaining vertices can refer to the above description and will not be repeated here.

In another embodiment, the control module 141 may generate an image adjustment instruction according to the displacement from an edge of the auxiliary range to an edge corresponding to the target range, so that the projection device 50 may move the edge of the projected image to the position of the corresponding edge of the target range according to the image adjustment instruction.

In one embodiment, the processor 15 may also display multiple grids in the auxiliary range. The shapes of these grids correspond to the outline of the projection image. In some application scenarios, the environment in which the projection image is projected may be a polyhedron, so that the shape of the projection image is deformed to have more sides. For example, FIG. 10 is a schematic diagram of a non-planar projection according to an embodiment of the present invention. Referring to FIG. 10, the object in the space (projection environment) into which the projection image is projected is, for example, a corner of a wall. When the projection image of the projection device 50 is projected onto the corner of the wall, the projection image appears on the wall surfaces W2 on both sides of the corner, so that the auxiliary range AR2 corresponding to the outline of the projection image in the captured image has six sides. Based on the principle that the optical path distance is proportional to the image size, the projected image on the left and right sides is larger than the center wall corner, resulting in image distortion.

In this application scenario, if the projection device 50 supports the geometric correction function, the projection image can be deformed. FIG. 11 is a schematic diagram of a user interface UI2 according to another embodiment of the present invention. Referring to FIG. 11 , the user interface UI2 not only presents the captured image, but also presents the auxiliary range AR2, the target range TR2, the geometric characteristics GC, the tool options TB and the grid GR located in the auxiliary range AR2. The projection image projected by the projection device 50 is an image having multiple grids GR.

The processor 15 may receive a second definition operation of the third position information of the target range TR2 through the input device 12, wherein the user draws the target range TR2 through the user interface UI2, and the processor 15 overlays the target range TR2 on the layer with the auxiliary range AR2, wherein the second position information includes the position on the boundary of the target range TR2. The third position information may be the position of the nodes (i.e., the intersection points of the line segments) and/or the line segments of the grid GR. The above-mentioned second definition operation is used to adjust the auxiliary range AR2 to the target range TR2, that is, to change the position of the nodes and/or line segments (of the outermost layer or other layers) of the grid GR. For example, the user draws the target range TR2 corresponding to the wall W2 through a drag operation.

The control module 141 of the computing device 10 can control the projection device 50 to enter the grid adjustment mode through the communication transceiver 13. After receiving the second definition operation, the control module 141 can determine the displacement of the nodes and/or line segments of the grid GR in the projected image (it can also evenly distribute the position of the grid GR), and generate an image adjustment instruction based on the displacement, so that the image adjustment instruction includes the displacement. The projection device 50 can change the node position of the grid GR according to the image adjustment instruction, so that the projected calibrated projection image is consistent with the target range TR2, thereby eliminating image deformation.

In summary, in the projection correction method and projection correction system of the embodiment of the present invention, the position and geometric characteristics of the projection image in the captured image are analyzed, and an auxiliary range corresponding to the outline of the projection image is presented on the user interface. In addition, according to the definition operation of the target range received by the user interface, the projection image projected by the projection device is adjusted to the position corresponding to the target range. In addition, the user interface can also present the critical range of the maximum range supported by the projection device and the grid applicable to the multi-plane environment.

Thus, the present invention can achieve (but is not limited to) the following features:

Provides a simple operation interface and calibration reference to avoid traditional remote control and button operation.

Assists projection devices without automatic calibration function to perform calibration.

Compared with the current automatic calibration technology, it can better meet the user's expected results.

Applicable to projection image correction in single plane and non-planar (multi-plane) environments.

However, the above is only the preferred embodiment of the present invention, and it cannot be used to limit the scope of the implementation of the present invention. That is, all simple equivalent changes and modifications made according to the scope of the patent application and the content of the invention description are still within the scope of the present invention. In addition, any embodiment or patent application of the present invention does not need to achieve all the purposes, advantages or features disclosed by the present invention. In addition, the abstract and title are only used to assist in searching for patent documents, and are not used to limit the scope of rights of the present invention. In addition, the terms "first", "second", etc. mentioned in the patent application are only used to name the element or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

PI, PI2: Projected image PP: Projection screen EP: Expected range P: Projector 1: Image correction system 10: Calculation device 11: Display 12: Input device 13: Communication transceiver 14: Memory 141: Control module 142: Image processing module 143, UI1, UI2: User interface 15: Processor 30: Image capture device 50: Projection device S410~S450, S610~S640: Steps W, W2: Wall L: Length D: Angle CI: Captured image AR, AR2: Auxiliary range LR: Critical range TR, TR2: Target range L1: First layer L2: Second layer L3: Third layer L4: Fourth layer L5: Fifth layer TAP: Auxiliary vertex position AAP: Target vertex position TP1: Displacement TB: Tool options GC: Geometric properties GR: Grid

Fig. 1A and Fig. 1B are schematic diagrams of known automatic correction of projection. Fig. 2A and Fig. 2B are schematic diagrams of projection on different walls. Fig. 3 is a block diagram of components of a projection correction system according to an embodiment of the present invention. Fig. 4 is a flow chart of a projection correction method according to an embodiment of the present invention. Fig. 5 is a schematic diagram of image capture according to an embodiment of the present invention. Fig. 6 is a flow chart of image analysis according to an embodiment of the present invention. Fig. 7 is a schematic diagram of geometric characteristics according to an embodiment of the present invention. Fig. 8 is a schematic diagram of a layer structure of a user interface according to an embodiment of the present invention. Fig. 9 is a schematic diagram of a user interface according to an embodiment of the present invention. Fig. 10 is a schematic diagram of projection on a non-planar surface according to an embodiment of the present invention. Figure 11 is a schematic diagram of a user interface according to another embodiment of the present invention.

S410~S450: Steps

Claims (22)

A projection calibration method includes: obtaining a captured image, wherein the image content of the captured image includes a projection image; obtaining first position information of the projection image from the captured image; loading the captured image into a user interface, wherein an auxiliary range based on the first position information is presented through the user interface; receiving a defined operation corresponding to a second position information of a target range on the user interface, wherein the defined operation The auxiliary range is adjusted to the target range, wherein the auxiliary range and a critical range are displayed in the user interface by a display, wherein the target range is less than or equal to the critical range, and the critical range is a maximum range of the projected image; and an image adjustment instruction is generated according to a position difference between the first position information and the second position information, wherein the image adjustment instruction is used to change the range of the projected image. In the projection correction method as described in claim 1, the step of obtaining the first position information of the projection image from the captured image includes: determining at least one contour position of the contour of the projection image in the captured image; and using the at least one contour position as the first position information, wherein the auxiliary range is generated based on the at least one contour position. As described in claim 1, the projection correction method further includes: performing at least one of the following image processing on the captured image before the step of obtaining the first position information of the projection image from the captured image: perspective transformation; grayscale processing; and noise reduction processing. The projection correction method as described in claim 1, wherein the step of loading the captured image into the user interface includes: using the captured image as a first layer; using the user interface to use the auxiliary range as a second layer and overlaying it on the first layer having the captured image, and the projection correction method further includes: in response to receiving the definition operation, overlaying the target range on the second layer through the user interface. The projection correction method as described in claim 1, wherein the outline of the projection image is a polygon, and the projection correction method further comprises: determining a geometric property of the polygon, wherein the user interface further presents the geometric property of the projection image, and the geometric property comprises at least one of length, angle and area. In the projection correction method as described in claim 1, the step of loading the captured image into the user interface includes: defining the critical range according to an adjustment parameter, wherein the adjustment parameter is a critical setting of at least one of a shape distortion correction range value and a screen displacement range value corresponding to a projection device. As described in claim 1, the step of loading the captured image into the user interface includes: defining a layer structure of the user interface, wherein the layer structure is, from low to high, the captured image, the auxiliary range, a geometric characteristic of the projection image, a critical range, and the target range. The projection correction method as described in claim 1, wherein the first position information includes at least one auxiliary vertex position of the auxiliary range, the second position information includes at least one target vertex position of the target range, and the step of generating the image adjustment instruction according to the position difference between the first position information and the second position information includes: determining a displacement from the auxiliary vertex position to a corresponding target vertex position, wherein the image adjustment instruction includes the displacement. In the projection correction method as described in claim 1, the step of loading the captured image into the user interface includes: displaying a plurality of grids in the auxiliary range, wherein the shapes of the grids correspond to the outline of the projection image. The projection correction method as described in claim 9, wherein the step of generating the image adjustment instruction based on the position difference between the first position information and the second position information includes: determining a displacement of the nodes corresponding to the contour in the grids based on the target range, wherein the image adjustment instruction includes the displacement. A projection correction system includes: a computing device and a projection device; the projection device is communicatively connected to the computing device and is used to project a projection image; the computing device includes: a display, an input device and a processor; wherein the display is used to display a user interface; the input device is used to receive an operation; and the processor is coupled to the display and the input device and is configured to: obtain a captured image, wherein the image content of the captured image includes the projection image; obtain a first position information of the projection surface from the captured image; load the captured image into the user interface, wherein the user interface presents a first position information based on the first position information; An auxiliary range of a position information; a definition operation of receiving a second position information corresponding to a target range on the user interface through the input device, wherein the definition operation is used to adjust the auxiliary range to the target range; and an image adjustment instruction is generated according to a position difference between the first position information and the second position information, wherein the image adjustment instruction is transmitted to the projection device to change the range of the projected image, wherein the display is used to display the auxiliary range and a critical range in the user interface, wherein the target range is less than or equal to the critical range, and the critical range is a maximum range of the projected image. The projection correction system as described in claim 11, wherein the processor is further used to: determine at least one contour position of the contour of the projection image in the captured image; and use the at least one contour position as the first position information, wherein the auxiliary range is generated based on the at least one contour position. A projection correction system as described in claim 11, wherein the processor is further used to: perform at least one of the following image processing on the captured image: perspective transformation; grayscale processing; and noise reduction processing. The projection correction system as described in claim 11, wherein the processor is further used to: use the captured image as a first layer; use the auxiliary range as a second layer and overlay it on the first layer having the captured image through the user interface; and in response to receiving the definition operation, overlay the target range on the second layer through the user interface. A projection correction system as described in claim 11, wherein the outline of the projection image projected by the projection device is a polygon, and the processor is further used to: determine a geometric property of the polygon, wherein the user interface further presents the geometric property of the projection image, and the geometric property includes at least one of length, angle and area. The projection correction system as described in claim 11, wherein the processor is further used to: receive an adjustment parameter from the projection device; define the critical range according to the adjustment parameter, wherein the adjustment parameter is a critical setting of at least one of a shape distortion correction range value and a screen displacement range value of the projection device. The projection correction system as described in claim 11, wherein the processor is further used to: define a layer structure of the user interface, wherein the layer structure is, from low to high, the captured image, the auxiliary range, a geometric characteristic of the projected image, a critical range, and the target range. A projection correction system as described in claim 11, wherein the first position information includes at least one auxiliary vertex position of the auxiliary range, the second position information includes at least one target vertex position of the target range, and the processor is further used to: determine a displacement from the auxiliary vertex position to a corresponding target vertex position, wherein the image adjustment instruction includes the displacement. A projection correction system as described in claim 11, wherein the processor is further used to: display multiple grids in the auxiliary range through the user interface, wherein the shapes of the grids correspond to the outline of the projection image. A projection correction system as described in claim 19, wherein the processor is further used to: determine a displacement of the nodes corresponding to the contour in the grids according to the target range, wherein the image adjustment instruction includes the displacement. The projection correction system as described in claim 11 further includes: an image capture device, which is communicatively connected to the computing device and is used to generate the captured image. A non-transient processor-readable storage memory stores at least one software module, and a processor executes the at least one software module to implement a projection correction method: obtaining a captured image, wherein the image content of the captured image includes a projection image; obtaining a first position information of the projection image from the captured image; loading the captured image into a user interface, wherein an auxiliary range based on the first position information is presented through the user interface; receiving a corresponding target range on the user interface A definition operation of a second position information, wherein the definition operation is used to adjust the auxiliary range to the target range, wherein the auxiliary range and a critical range are displayed in the user interface by a display, wherein the target range is less than or equal to the critical range, and the critical range is a maximum range of the projected image; and an image adjustment instruction is generated according to a position difference between the first position information and the second position information, wherein the image adjustment instruction is used to change the range of the projected image.

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