JP2007251398A - Image data reception processing device and transmission processing device and image data processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a processing load of decoding and display in the reception side video display, and to reproduce a moving video smoothly. <P>SOLUTION: An image data processor comprises a section for acquiring the difference image data between the frames of image data, an optimization section for reducing the amount of the difference image data, a section for generating attribute information of the difference image data, and a section for transmitting the attribute information and the optimized difference image data on the transmission side. On the reception side, an analysis section analyzes the attribute information taken out from the received signal, a decoding section restores moving video data when the received image data is the difference image data and develops it into a storage section, and pixel conversion of the image data read out from the storage section is performed before it is outputted as a display signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image data reception processing device, a transmission processing device, and an image data processing method. For example, the present invention is an effective device and method for transmitting and projecting image data processed by a personal computer to an electronic projector.

In the presentation, image data processed by a personal computer is transmitted to an electronic projector. In a system for transferring and displaying image data displayed on a personal computer via a network to a video display device such as a projector, the video display device on the receiving side needs to decode and display the received image data.
JP 2000-66799 A JP 2000-209560 A

  In recent years, the performance of CPUs used in personal computers has increased, and the opportunities for playing moving image content on personal computers have increased. However, built-in devices such as projectors are often inferior in processing speed to personal computers in which the processing performance of the CPU is significantly improved. For this reason, due to the difference in CPU processing speed between the transmitting side and the receiving side, there is a processing delay on the receiving side, and it is difficult to display a moving image smoothly especially during moving image reproduction.

  Therefore, the present invention optimizes the image to be transmitted on the high-performance personal computer side, thereby reducing the processing load of decoding and display in the video display device on the receiving side, and enabling smooth playback of moving images. It is an object of the present invention to provide a data reception processing device, a transmission processing device, and an image data processing method.

  To achieve the above object, according to one aspect of the present invention, on the transmission side, an image data memory, a difference image data acquisition unit that extracts image data from the image data memory and acquires difference image data between frames, and An optimization unit that reduces the amount of difference image data; an attribute information generation unit that generates attribute information of the difference image data; and a transmission unit that transmits the attribute information and the optimized difference image data. On the other hand, on the receiving side, a receiving unit, a determining unit that determines attribute information from the received signal and image data accompanied by the attribute information, and analyzing the attribute information, the image data is difference image data. An analysis unit for determining whether or not the image data is differential image data; when the image data is differential image data, the differential image data decoding unit that restores moving image data using the differential image data and develops the data in the storage unit; A pixel conversion unit that performs pixel conversion of the image data read from the storage unit and outputs the pixel data as a display signal.

  By the above means, when the transfer rate of the network is low, even if the transfer rate is not sufficient in the surrounding environment in the case of a wireless network, the transmission interval of the differential image data can be maintained without being influenced so much, and the display on the receiving side The apparatus also reduces the processing load required for display processing.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the appearance of a color projector 11 used in this embodiment. The color projector 11 has a cabinet 12 formed in a substantially thin box shape.

  In the cabinet 12, a projection lens 13 for enlarging and projecting an image on a screen (to be described later) serving as an image projection surface and a distance measuring unit 14 are disposed close to the front panel 12 a.

  The distance measuring unit 14 measures the distance from the projection lens 13 to the screen, and automatically measures the distance to two different positions in the horizontal direction on the screen without moving the cabinet 12. have.

  FIG. 2 schematically shows the color projector 11 connected to the personal computer 20 via, for example, a wireless LAN.

  FIG. 3 shows functional blocks inside the personal computer 20 and the projector 11. The personal computer 20 includes an image memory 201 such as a hard disk, an image data processing unit 202, a transmission / reception unit 203, and a system control unit 204. When transmitting image data to the projector 11, the image data processing unit 202 takes in the image data from the image data memory 201 and generates data to be transmitted. The system control unit 204 controls the image data memory 201, the image data processing unit 202, and the transmission / reception unit 203 in an integrated manner.

  Here, the image data processing unit 202 includes an image data acquisition unit 02a, a difference image data acquisition unit 02b, an attribute information generation unit 02c, a difference image data optimization unit 02d, and a transmission data generation unit 02e. A still image data processing unit 02f and a reduction processing unit 02g are also included. The reduction processing unit 02g operates together with the difference image data optimization unit 02d and can perform reduction processing of the difference image data. Therefore, the reduction processing unit 02g may be included in the difference image data optimization unit 02d.

  An image displayed on a personal computer is often a character or a figure, and in a general application, there are few situations in which the entire screen changes, and there are many cases where only a partial screen change occurs. Therefore, the difference image obtained by cutting out only the changed part on the screen of the personal computer 20 is compressed and transmitted on the personal computer side, and the data received on the projector 11 side is expanded and displayed on the screen.

  In the personal computer 20, the changing location is acquired as differential data by dividing the time at regular intervals to capture changes in the screen data, or by acquiring a change event using a virtual graphic driver. At this time, it is determined that the area where the change event has occurred is based on the moving image content under the following conditions that are the characteristics of the moving image.

(1) The result of detecting the screen change portion shows almost the same area, and this is repeatedly detected.
(2) In almost the same region, the change is repeated at short intervals.
(3) The window position of the moving image playback application registered in advance overlaps the screen change portion.

  The transmission source first detects the screen data according to the flowchart described later, and determines whether or not it is a moving image part based on the determination criteria in the previous section. Information obtained by this determination is attached to the image data as attribute information (transmission data generation) and transmitted to the projector 11. At this time, the image of the moving image portion is encoded as difference image data. However, as the optimization of the difference image data on the transmission side, the difference image data is encoded by reducing the size or encoding the color data to reduce the data amount. Reduce the amount of data.

  Data transmitted from the personal computer 20 is transferred from the transmission / reception unit 203 to the projector 11 which is a video display device via a network such as Ethernet (registered trademark). The projector 11 receives data transmitted from the personal computer 20 by the transmission / reception unit 120. In addition to the transmission / reception unit 210, the projector 11 includes a determination unit 121, an image data processing unit 122, a storage unit 123, a CPU 124, pixel conversion units 125 and 126, a synthesis circuit 127, and a projection unit 128. The CPU 124 controls the transmission / reception unit 120, the determination unit 121, the image data processing unit 122, the storage unit 123, the pixel conversion units 125 and 126, and the like.

  The received data captured from the transmission / reception unit 120 is subjected to separation of attribute information and image information by the determination unit 121, and the separated attribute information and image data are input to the image data processing unit 122. The attribute information identifies whether the transmitted image data is normal update data or moving image data.

  The image data processing unit 122 includes an attribute information analysis unit 22a. The attribute information analysis unit 22a analyzes the attribute information. The update flag of the image data sent, the identification information of the still image / moving image, and the sent image data. Get coordinate information to be displayed. The coordinate information is information for setting the output timing of the image.

  Further, if the transmitted image data is difference image data, the difference image data is encoded, and thus has a difference image data decoding unit 22b for decoding the original difference image data. Further, since the difference image data decoding unit 22b has a frame of the moving image data before the update in the frame memory, the updated moving image data is converted using the newly received difference image data and the moving image data before the update. Reproduce.

  As described above, the projector 11 checks the coordinates and attribute information associated with the image data when the data is received according to the flowchart described later. At this time, when it is determined from the attribute information that the image data is of the moving image part, the restoration process is performed in the reverse order of the method performed at the time of optimization. For example, when the size is reduced, the original size is restored and expanded in the storage unit 123. Otherwise, proceed as usual.

  The image data expanded in the storage unit 123 is subjected to enlargement processing by hardware in the pixel conversion units 125 and 126, and is input to the projection unit 128 via the synthesis circuit 127. The projection unit 128 images input image data with a spatial modulation element (for example, a liquid crystal element), and optically enlarges and projects the input image data.

  Here, two systems of pixel conversion units 125 and 126 are provided, but basically only one of them may be provided.

  By providing two systems of pixel conversion units 125 and 126, the following functions can be obtained. The images of the moving image portion and the non-moving image portion described above are expanded to different display memories (for example, a plurality of frame memories are prepared in the storage portion 123), and the two systems of pixel converting portions 125 and 126 are used. The method of inputting to each may be sufficient. Then, the input to each of the pixel conversion units 125 and 126 can handle different refresh rates, and the non-moving image portion and the moving image portion output two separate signals in accordance with the respective update speeds and resolutions, and the synthesis circuit The screen of the transmission source can be restored by fitting the video of the video part into the video of the non-video part. With regard to moving image processing, update speed is emphasized, and still image processing can be performed with emphasis on image quality even if the speed is low.

  An example of image processing on the personal computer 20 side will be described with reference to FIG. Image data is acquired from the image data memory 201 (step SA1). The previous image data and the current image data are compared to determine whether or not there has been a change (step SA2). That is, the difference between frames is taken. The portion without change is a still image, and the portion that has been converted (the portion in which the difference is generated) is a moving image. If there is a change, a change (that is, difference image data) is acquired (step SA3). Further, it is determined whether the position (coordinate position) where the difference image data is acquired and the size of the area are the same position and size for several times (step SA4).

When the difference image data is acquired (coordinate position) and the size of the area is the same position several times, for example, a moving image is inserted as a picture-in-picture in a still image. When the area from which the difference image data is acquired is determined to be a moving image area, the coordinate information of this area is registered in the attribute information (step SA5). Then, the optimization process of the difference image data is performed (step SA6). As described above, the optimization processing is to reduce the data amount of the difference image data by performing reduction or encoding by reducing the color data in order to reduce the data amount. The optimized difference image data is generated as transmission data (step SA7).
If the area from which the difference image data has been acquired is not determined to be a moving image area in step SA4, the area is simply determined as an updated area, and the process proceeds to transmission data generation (step SA7). When transmission data is generated, data transmission is performed (step SA7), and when the data transmission is completed (step SA9), the processing is terminated.

  Therefore, according to the above processing, the image data of the moving image area is converted into differential image data in the first stage to reduce the data amount, and further optimized by the next second stage to further increase the data amount. Is reduced.

  This means that the follow-up performance of moving images is good on the transmission side and the reception side even in the case of a line with a reduced data amount and a small capacity. As described above, since this apparatus can specify a moving image area, it can also specify a still image area. The still image area may be updated. In such a case, the change of the still image area does not need to be immediately reflected in the receiving projector. Therefore, the transmission of still image data is a method of transmitting first as low-resolution image data, then dividing the screen into regions, for example, and transmitting high-resolution image data in multiple times for each region. Also good.

  FIG. 5 shows an operation flow on the projector 11 side. When data is received (step SB1), attribute information is first acquired (step SB2). Then, decoding and analysis are performed (step SB3). If the attribute information includes a flag indicating that it is a moving image, an image restoration process is performed on the transmitted image data (step SB4). This restoration process is a process in which the reverse procedure is performed on the transmission side. When the moving image data is restored, it is copied to the storage unit 123 for display. At this time, the address to be stored is determined based on the coordinate information.

  If there is no flag indicating that it is a moving image in step SB4, the image data is updated image data, and is copied to the storage unit 123 for display in step SB6. Then, the image data in the storage unit 123 is read out and displayed as an image (step SB7). When the display is completed, the operation is completed (step SB8).

  The present invention is not limited to the above embodiment. Although the projector 11 has been described as a representative, a display device such as a plasma display may be used. Furthermore, the one-to-one relationship between the personal computer and the projector has been described. However, the present invention is also effective in an environment where a plurality of display devices are connected to the personal computer via a network.

  FIG. 6 shows an environment in which an image is transmitted from the personal computer 20 to a projector 11A-11C installed in a plurality of event venues or classrooms via a wireless LAN. In such a case, the moving image information transmission method described above is effective in order to avoid congestion of the communication line. In this case, some projectors may have different image data processing capabilities depending on the model and manufacturer. In such a case, the maximum resolution when the personal computer 20 transmits still image data and the transmission speed when transmitting still image data and moving image data (difference image data) may be switched.

  FIG. 7 is an operation explanatory diagram when the personal computer 20 inquires of each projector 11A-11C about the processing capability at the time of activation. The personal computer 20 determines the resolution / transmission speed common to each projector when there is a response of the capability information of resolution / transmission speed from each projector 11A-11C. Then, after the resolution / transmission speed information is transmitted to each projector, image data processing is started. When the resolution / transmission speed information is sent from the personal computer 20, each projector 11A-11C sets the processing speed and sets the resolution. Also, aspect ratio information may be processed along with the resolution.

  By using the image data processing apparatus and the image data display processing method described above, if the transfer rate of the network is low, even if the transfer rate is not sufficient in the surrounding environment if it is a wireless network, the difference image data is not significantly affected. Transmission intervals can be maintained, and the display device on the receiving side can also reduce the processing load required for display processing.

  Although the transmission source is a computer equipped with a CPU having a high processing capability, a product such as a video display device generally has a high-performance CPU such as a personal computer. Therefore, a process for restoring the optimization process performed at the transmission source may be a load. For example, processing such as enlargement / reduction may not be common due to the load imposed by software, but in this apparatus, the reduced image is handled as it is, and finally a pixel conversion circuit or a synthesis circuit (commonly referred to as picture-in-picture) is used. Function) is handled by hardware. By utilizing this, it is possible to achieve both high-speed display and restoration of the transmission source image.

  The display size of an image of a personal computer is variably changed in a rectangular area called a window. Therefore, in a personal computer, the moving image portion can be easily enlarged / reduced by a user operation. However, when the display device follows this enlargement / reduction, only the moving image is processed by a separate system (such as a dedicated pixel conversion unit). Can follow. Furthermore, the transmission side can also reduce and transmit still image data, and the reception side can enlarge the received still image data with a dedicated pixel conversion unit.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

It is a general-view figure of a color projector. FIG. 2 is a schematic view showing a usage state of the present invention applied to a personal computer and a projector. It is a figure which shows the example of the functional block in a personal computer and a projector. 5 is a flowchart shown for explaining the operation on the personal computer side. It is the flowchart shown in order to demonstrate the operation example by the side of a projector. It is a figure which further shows the example of application of the apparatus and method concerning this invention. It is a figure explaining the initial setting operation | movement of the system of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Projector, 120 ... Transmission / reception part, 121 ... Judgment part, 122 ... Image data processing part, 123 ... Memory | storage part, 124 ... CPU, 125, 125 ... Pixel conversion Part, 127 ... synthesis circuit, 128 ... projection part,
DESCRIPTION OF SYMBOLS 20 ... Projector, 201 ... Image data memory, 202 ... Image data processing part, 203 ... Transmission / reception part, 204 ...... System control part.

Claims (10)

A receiver,
A determination unit for determining attribute information and image data accompanied by the attribute information from the received signal;
An analysis unit that analyzes the attribute information and determines whether the image data is difference image data;
When the image data is difference image data, a difference image data decoding unit that restores moving image data using the difference image data and develops the image data in a storage unit;
A pixel conversion unit that performs pixel conversion of the image data read from the storage unit and outputs it as a display signal;
An image data processing apparatus. The image data processing apparatus according to claim 1, wherein the difference image data is difference image data having a reduced size, and the restored moving image data is enlarged in size by the pixel conversion unit. The image according to claim 1, wherein the pixel conversion unit includes the moving image data and still image data, and the output of the moving image data and still image data pixel conversion units is combined by a combining circuit 127. Data processing device. Image data memory;
A difference image data acquisition unit for extracting image data from the image data memory and acquiring difference image data between frames;
An optimization unit that reduces the data amount of the difference image data;
An attribute information generation unit for generating attribute information of the difference image data;
An image data processing apparatus comprising: a transmission unit that transmits the attribute information and the optimized difference image data. The image data processing apparatus according to claim 4, further comprising a still image data processing unit, wherein the attribute information includes a flag for identifying whether the accompanying image data is a still image or a moving image.   The image data processing apparatus according to claim 4, wherein the optimization unit performs a reduction process on the difference image data. On the sending side,
In the difference image data acquisition unit, the image data is extracted from the image data memory, the difference image data between frames is acquired,
The optimization unit reduces the data amount of the difference image data,
An attribute information generation unit generates attribute information of the difference image data,
Send the attribute information and the optimized difference image data in the transmission unit,
On the receiving side,
The determination unit determines the attribute information and the image data accompanied by the attribute information from the received signal,
The analysis unit analyzes the attribute information to determine whether the image data is difference image data,
In the difference image data decoding unit, when the image data is the difference image data, the difference image data is used to restore the moving image data and develop it in the storage unit,
The pixel conversion unit performs pixel conversion of the image data read from the storage unit and outputs it as a display signal.
An image data processing method comprising: The image data processing method according to claim 7, wherein the optimization unit performs a reduction process on the difference image data, and the pixel conversion unit performs an enlargement process.   The image data processing method according to claim 7, wherein the pixel conversion unit performs pixel conversion on the moving image data and the still image data separately. The image data processing method according to claim 7, wherein the transmission side also reduces and transmits still image data, and the reception side enlarges the received still image data with a dedicated pixel conversion unit.

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