WO2004111991A1 - High-speed image frame plotting method - Google Patents

Abstract

An image plotting device includes a display for displaying an image frame on a screen, an image memory having a plurality of frame memories for storing image frames, a synthesizing section for synthesizing the image frames read out from the frame memory selected from the image memory, and a display section for outputting the synthesized image frame output from the synthesizing section to the display so as to be displayed on the display screen and simultaneously outputting the synthesized image frame to the frame memory selected from the image memory.

Description

 Specification

 High-speed image frame drawing method

 The present invention relates to an image drawing device and an image drawing method of a display controller for displaying an image frame. Background art

 -In general, portable information terminals such as PDAs (Personal Digital Assistants) and car navigation systems (Car Na viati on Syst ems) use LCDs (Liquid Crystal Display). It has a display controller for drawing image frames on the screen of the display at high speed.

 The display controller reads the image frames from the frame memories stored in the different memory spaces, performs a combining process such as a transmission process and a blending process, and displays them as one image frame on the display screen. These functions are called superimposed display.

 In the superimposed display by the conventional display controller, the data of the synthesized image frame is output to the display and displayed on the display screen. In order to further superimpose a new image frame on the displayed composite image frame (here, such a process is called infinite superimposition display), it is necessary to read data from the display and store it in the frame memory .

 When infinitely superimposed display is performed using the conventional method, there is a problem that the speed of drawing processing on the display screen is reduced by the amount of reading image frame data from the display and storing it in the frame memory.

As prior art documents related to the present invention, Japanese Patent Application Laid-Open No. Hei 9-134428 discloses a display method of compressed image data using a DRAM, and Japanese Patent Application Laid-Open No. 2000-193888 discloses a plurality of captured partial images. An image forming apparatus that generates a synthesized image by synthesizing the images. Disclosure of the invention

 The present invention has been made in view of the above problems, and provides an image drawing apparatus and an image drawing method that enable high-speed infinite superimposed display by a display controller without reading display image data from a display. It is intended to

 In order to achieve the above object, an image drawing device of the present invention includes a display for displaying an image frame on a screen, an image memory including a plurality of frame memories for storing the image frame, and a selected one of the image memories. A synthesizing unit for synthesizing each image frame read from the frame memory, and outputting the synthesized image frame output from the synthesizing unit to the display for displaying on a screen of the display; A display unit that simultaneously outputs the image data to the selected frame memory of the image memory.

 According to another aspect of the present invention, there is provided a portable information terminal comprising: a display for displaying an image frame on a screen; and an image memory including a plurality of frame memories for storing the image frame. An image drawing method for superimposing and displaying image frames, comprising: a synthesis procedure for synthesizing each image frame read from a frame memory selected from the image memory; and a synthesized image output by the synthesis procedure. A display step of outputting a frame to the display for display on the screen of the display and simultaneously outputting the frame to a selected frame memory of the image memory.

 In the image drawing apparatus and the image drawing method of the present invention, when an image frame is read out from each frame memory, a synthesizing process is performed, and when the synthesized image frame is output to a display screen, the image is simultaneously stored in the frame memory. Output a frame. This eliminates the need to read image frames from the display, and enables high-speed infinite superimposed display. BRIEF DESCRIPTION OF THE FIGURES

Other objects, features and points of the present invention will be described with reference to the accompanying drawings. Clarification will be made by referring to the detailed description of.

 FIG. 1 is a block diagram showing a system configuration of a portable information terminal to which an image drawing device according to one embodiment of the present invention is applied.

 FIG. 2 is a block diagram showing a display controller in the portable information terminal of FIG.

 FIG. 3 is a diagram for explaining a conventional infinite superimposed display method.

 FIG. 4 is a diagram for explaining an embodiment of an image drawing method for performing infinitely superimposed display according to the present invention.

 FIG. 5 is a diagram for explaining another embodiment of the image drawing method for performing infinitely superimposed display according to the present invention.

 FIG. 6 is a diagram for explaining still another embodiment of the image drawing method for performing infinite superimposed display according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

 Embodiments of the present invention will be described with reference to the accompanying drawings.

 FIG. 1 shows a system configuration of a portable information terminal to which an image drawing device according to one embodiment of the present invention is applied. This portable information terminal is more specifically a PDA or a car navigation system.

 In the portable information terminal shown in FIG. 1, CPU 1 is a processor that controls the entire system, and reads a program stored in an external memory 4 via a memory controller 3 to operate. In the mobile information terminal shown in Fig. 1, CPU 1, VR

The AM 2, the memory controller 3, and the display controller 5 are connected to each other by a bus 9.

 VRAM 2 is an image memory (memory buffer) for storing image frames, and is configured to include a plurality of N frame memories (frame memory 1, frame memory 2,..., Frame memory N). . Each frame memory has a storage capacity for storing a data amount of an image frame corresponding to one screen of the display 6.

Memory controller 3 controlled by CPU 1 provides external memory to CPU 1. It has an interface function with the CPU 4 and performs data transfer between the CPU 1 and the external memory 4. Instructed to read data from CPU1: ^, memory controller 3 reads the designated data from external memory 4 and transfers it to CPU1. When data writing is instructed by the CPU 1, the memory controller 3 transfers data from the CPU 1 to the external memory 4 in order to write the specified data to the external memory 4.

 The display controller 5 controlled by the CPU 1 reads image frames from the respective frame memories of the VRAM 2 and performs superimposing processing such as # 1 processing and blend processing. Is output to VRAM2 and display 6 at the same time. By outputting the data of the image frame after the synthesizing process to the display 6, superimposed display is performed on the screen of the display 6.

 FIG. 2 shows a configuration of the display controller 5 in the portable information terminal of FIG.

 In the display controller 5 of FIG. 2, the synthesizing unit 7 reads an image frame from a specified frame memory in the VRAM 2 and performs a synthesizing process such as a transmission process and a blending process. The display unit 8 outputs the data of the synthesized image frame obtained as a result of the synthesis processing by the synthesis unit 7 to the display 6 and the selected frame memory in the VRAM 2 at the same time.

 Similarly to the conventional display controller, a signal line for data transfer from the output of the display unit 8 to the input of the display 6 is formed in the display controller 5 of this embodiment. In addition to this signal line, the display controller 5 of the present embodiment is provided with a signal line for data transfer from the output of the display unit 8 to the bus 9 connecting the VRAM 2 and the display controller 5 (indicated by a black arrow in FIG. 2). Are additionally formed.

The output destination of the composite image frame on the display unit 8 is designated by the CPU 1 as needed. That is, the CPU 1 outputs an instruction for specifying the output destination of the display unit 8 to the display controller 5 at an arbitrary time. Based on the instruction to specify the output destination from CPU 1, the output destination of the composite image frame from display unit 8 is (a) display 6 It is possible to specify either (b) the display 6 and the selected frame memory in the VRAM 2 and (c) only the selected frame memory in the VRAM 2.

 Next, in order to clarify the features of the infinite superimposed display system according to the present invention, a conventional non-superimposed superimposed display system will be described. FIG. 3 is a diagram for explaining a conventional infinite superimposed display method.

 In the conventional method of FIG. 3, in step 1, each image frame is written to the frame memory 11 and the frame memory 12.

 In step 2, the image frames read from the frame memories 11 and 12 are combined by the display controller, and the combined image frame obtained as a result of the combining process is displayed on the display screen. In step 3, a display image frame is read from the display and the display image frame is written to the frame memory 1 in order to further synthesize a new image frame with the displayed image frame.

 In step 4, a new image frame is written to frame memory 12.

 Finally, in step 5, each image frame force S read from the frame memory 1 and the frame memory 2 is combined by the display controller, and the combined image frame obtained as a result of the combining process is displayed on the display screen. Is displayed.

 In the conventional method, infinitely superimposed display is realized by repeating each of the steps 3 to 5 described above. As described above, when the conventional method is used, every time a new image frame is further combined with a display image frame, the data of the display image frame is read out from the display and transferred to the frame memory 1 or the frame memory_2. Since it needs to be stored, there is a problem that the drawing speed on the display screen becomes slow.

 FIG. 4 is a diagram for explaining an embodiment of an image drawing method for performing infinitely superimposed display according to the present invention.

The image drawing method of this embodiment uses the disk shown in FIG. 2 to solve the problem of the conventional method. This is executed by the spray controller 5. In the embodiment of FIG. 4, based on the designation from the CPU 1 to the display controller 5, the output destination of the composite image frame on the display unit 8 is the display frame (b) described above and the selected frame image in the VRAM 2. Mori is specified in advance.

 As shown in FIG. 4, in step 1, each image frame is written to the frame memory 1 and the frame memory 12.

 In step 2, each image frame read from the frame memory 11 and the frame memory 12 is synthesized by the display controller 5, and the synthesized image frame obtained as a result of the synthesis processing is simultaneously sent to the display 6 and the frame memory 11. Is output. By outputting the combined image frame to the display 6, the combined image is displayed on the screen of the display 6.

 In step 3, a new image frame to be synthesized is written to frame memory_2.

 Finally, in step 4, each image frame read from the frame memories 11 and 2 is synthesized by the display controller 5, and the synthesized image frame obtained as a result of the synthesizing process is displayed on the display 6 with the frame memory. Output to 1 at the same time. By outputting the composite image frame to the display 6, the composite image is displayed on the screen of the display 6.

 In the image drawing method of the above embodiment, infinite superimposed display is realized by repeating each procedure of Step 3 and Step 4. The combined image frame data is output to the display 6 by the display controller 5 and written to the selected frame memory in the VRAM 2 at the same time, so there is no need to read the display image data from the display 6. Accordingly, high-speed infinite superimposed display can be performed on the screen of the display 6.

 FIG. 5 is a diagram for explaining another embodiment of the image drawing method for performing infinitely superimposed display according to the present invention.

The image drawing method of this embodiment is executed by the display controller 5 of FIG. 2 in order to solve the problem of the conventional method. In the embodiment of FIG. 5, based on the designation from the CPU 1 to the display controller 5, the composite image frame of the display unit 8 is As the output destination, only the selected frame memory in the VRAM 2 of (c) in step 2 is specified, and the display 6 and the selected frame memory in VRAM 2 of (b) in step 4 are specified.

 As shown in FIG. 5, in step 1, an image frame is written to the frame memory 11 and the frame memory 2.

 In step 2, each image frame read from the frame memory 1 and the frame memory 12 is synthesized by the display controller 5, and the synthesized image frame obtained as a result of the synthesis processing is output only to the frame memory 1. You. At this time, the composite image frame is not output to the display 6. Therefore, the composite image is not displayed on the screen of the display 6 at this time.

Next, in step 3, a new image frame to be cane synthesis is written into the frame memory _ _2.

 Finally, in step 4, each image frame read from the frame memory 1 and the frame memory 12 is synthesized by the display controller 5, and the synthesized image frame obtained as a result of the synthesis processing is displayed on the display 6 and the frame memory. Output to Molly 1 at the same time. By outputting the composite image frame to the display 6, the composite image is displayed on the screen of the display 6.

 In the embodiment shown in FIG. 5, by combining the images without outputting them to the display 6 and writing them to the frame memory, the intermediate image frames in the middle of the infinite superimposed display are displayed on the screen of the display 6 without being displayed. Only the image frame after the completion of the synthesizing process can be displayed. Therefore, higher-speed infinite superimposed display on the screen of the display 6 is possible.

 FIG. 6 is a diagram for explaining still another embodiment of the image drawing method for performing infinite superimposed display according to the present invention.

The image drawing method of this embodiment is executed by the display controller 5 of FIG. 2 in order to solve the problem of the conventional method. In the embodiment of FIG. 6, based on the designation from the CPU 1 to the display controller 5, the output destination of the composite image frame on the display unit 8 is determined in steps 2 and 4 in the display 6 and the VRAM 2 in (b) above. The selected frame memory is designated, and in steps 5 and 6, (a) Only display 6 is specified.

 As shown in FIG. 6, in step 1, each image frame is written to the frame memory 1 and the frame memory 12.

 In step 2, each image frame read from the frame memory 1 and the frame memory 2 is synthesized by the display controller 5, and the synthesized image frame obtained as a result of the synthesis processing is simultaneously output to the display 6 and the frame memory 3. . By outputting the combined image frame to the display 6, the combined image is displayed on the screen of the display 6. At this time, the data of the synthesized image frame obtained as a result of the first synthesis processing is stored in the frame memory 13 in the VRAM 2.

 In step 3, a new image frame to be synthesized is written to frame memory 12.

 In step 4, each image frame read from the frame memories 2 and 3 is synthesized by the display controller 5, and the synthesized image frame obtained as a result of the synthesizing process is simultaneously output to the display 6 and the frame memory 14. Is done. By outputting the combined image frame to the display 6, the combined image is displayed on the screen of the display 6. At this time, the data of the synthesized image frame obtained as a result of the second synthesis processing is stored in the frame memory 4 in the VRAM 2.

 In step 5, in order to return the screen display of the display 6 to the previous screen, the composite image frame read from the frame memory 3 is output only to the display 6 by the display controller 5. Therefore, the first combined image (the previously displayed combined image) is displayed on the screen of the display 6.

 In step 6, the composite image frame read from the frame memory_4 is output only to the display 6 by the display controller 5 in order to advance the screen display of the display 6 to the next screen. Therefore, the second composite image (the composite image displayed this time) is displayed on the screen of the display 6.

In the embodiment of FIG. 6, when the display unit 8 of the display controller 5 outputs the synthesized image frame from the synthesis unit 7 to the selected frame memory of the VRAM 2, The output destination of the composite image frame is cyclically selected. The previously displayed composite image frame (for example, the composite image displayed in step 2 of FIG. 6) is stored in the frame memory in VRAM 2 (for example, the frame memory 13 in step 2 of FIG. 6). The composite image frame displayed this time (for example, the composite image displayed in step 4 in FIG. 6) is held in the frame memory in VRAM 2 (for example, the frame memory 4 in step 4 in FIG. 6). Then, by selectively outputting any one of the composite image frames to the display 6, either the composite image displayed last time or the composite image displayed this time can be instantly displayed on the screen of the display 6. Has been established.

 In the embodiment of FIG. 6, by controlling to write the synthesized image frame cyclically to the frame memory in VRAM 2, switching between the previous screen and the next screen can be easily realized, and high-speed drawing is possible. Become.

 As described above, in the image drawing apparatus and the image drawing method of the present invention, when an image frame is read out from each frame memory and combined, and the combined image frame is output to a screen such as a display, Outputting the image frames to the frame memory also eliminates the need to read the image frames from the display, enabling high-speed infinite superimposed display.

 As described above, the present invention has been described based on some embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made within the scope described in the following claims.

Claims

The scope of the claims 1. A display that displays the image frame on the screen,  An image memory including a plurality of frame memories for storing image frames; and a synthesizing unit that performs a synthesizing process on each image frame read from the selected frame memory of the image memory.  a display unit that outputs a composite image frame output from the tfif self-synthesis unit to the display for display on the screen of the display, and simultaneously outputs the frame to a selected frame memory of the image memory.  An image insertion device comprising: 2. The output destination of the composite image frame from the display unit is specified to one of the display only, the selected frame memory of the display and the image memory, and only the selected frame memory of the image memory. 2. The image drawing apparatus according to claim 1, further comprising a control unit. (3) When outputting the synthesized image frame from the synthesizing unit to the selected frame memory of the image memory, the display unit cyclically selects an output destination of the synthesized image frame, thereby displaying the previously displayed image. A composite image frame is stored in the image memory, and the composite image frame displayed last time is instantaneously displayed on the screen of the display by outputting the composite image frame to the display. The image drawing device according to claim 1. 4. The display unit outputs the composite image frame to the display by the control unit designating the output destination of the composite image frame from the display unit to only the selected frame memory of the image memory. 3. The image drawing apparatus according to claim 2, wherein the image is output only to the image memory without performing the processing. 5. A display for displaying the image frame on the screen, and a display for storing the image frame. A portable information terminal having an image memory including a plurality of frame memories, the image drawing method performing superimposed display of image frames,  a synthesizing procedure for synthesizing each image frame read from the selected frame memory of the it's own image memory;  A display step of outputting the synthesized image frame output by the synthesizing procedure to ffff's own display for displaying on the screen of the display, and simultaneously outputting to the selected frame memory of the image memory.  An image drawing method, comprising: 6. In the image drawing method, the output destination of the composite image frame from the knitting display unit is: the display only, the display and the selected frame memory of the image memory, and the selected frame memory of the image memory. 6. The image drawing method according to claim 5, further comprising a designation procedure for designating any one of the following. 7. In the ttflB display procedure, when the composite image frame output by the composite procedure is output to the selected frame memory of the image memory, the output destination of the composite image frame is cyclically selected. Holding the displayed combined image frame in the image memory, and outputting the combined image frame to the display so that the previously displayed combined image frame can be instantaneously displayed on the screen of the display. 6. The image drawing method according to claim 5, wherein: 8. In the specifying step, the output destination of the composite image frame in the display step is specified only to the selected frame memory of the image memory, so that the composite image frame is output to the display in the display step. 7. The image drawing method according to claim 6, wherein the image is output only to the image memory without any processing.