JP2006235339A - Vector scan transmission method and transmission device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vector scan transmission method and a transmission device using the same for shortening time from data compression up to display. <P>SOLUTION: In an image drawn in a display area where the image can be displayed to the maximum, the address and attribute of a partial area in a partial area showing the area of an image required to be re-written from the state displayed at present are transmitted. A memory for receiving has the same address constitution as a video RAM for drawing the display area, and receives data of the partial area, re-writes only the data of the partial area and displays it. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless communication apparatus used for data communication for communicating a large amount of data at high speed, such as between personal computers or between a personal computer and a liquid crystal projector apparatus, and a technical field for controlling the wireless apparatus.

When a personal computer is connected to a display device, such as a liquid crystal projector device or a television, and a presentation is made based on information stored in the storage device of the personal computer, the personal computer sends the entire screen to the projection display device, It was common to display each screen. The same technique has been used when transferring images using a wireless device (see Patent Document 1).
JP 2003-246996 A

  In this conventional method, even when the change portion on the screen is small, it is necessary to transfer the data of the entire screen from the personal computer to the projection display device via the wireless device. Since wireless data transfer is usually serial transfer using one frequency, it takes time to transfer even if the image is highly compressed. Since the transfer time could not catch up, it was difficult to display at the desired speed.

  In recent years, a universal serial bus (USB) has been generally used for an external interface of a personal computer. Since this method is serial transfer, it takes time to transfer large data such as images. Therefore, it takes less time for compression and data transfer to transfer data after compressing data inside the personal computer than to perform data compression after transferring to an external data compression device via USB. There are advantages. However, since a personal computer generally operates on an operating system, it cannot be expected to compress data at the processing speed of the original central processing unit because the central processing unit cannot concentrate solely on data compression.

  Since the image data is two-dimensional data, if the length of each side of the image is halved, the data amount is reduced to a quarter. When the entire screen is transferred as shown in the prior art, the time required for each process of data compression, data transfer, and data display is a simple calculation and increases in proportion to the square of the image size. When compressing, transferring, and displaying data continuously like a movie, data compression, data transfer, and display are performed by reducing only the portion that changes the display, not the entire screen, and data compression. The time from display to display can be shortened.

  According to the vector scan transmission method of the present invention, the image that needs to be rewritten from the currently displayed state in the display area among the images drawn in the display area that can display the image to the maximum extent. The address and attribute of the partial area in the partial area indicating the area are transmitted. The receiving memory has the same address configuration as the video ram for drawing the display area, receives the data of the partial area, and rewrites and displays only the data of the partial area.

  When the partial area is a rectangle, two points on the diagonal of the rectangle are selected as the start point indicating the start of the partial area and the end point indicating the end of the partial area. The image displayed in the partial area may be a moving image.

  Moreover, the electric transmission apparatus of this invention uses these methods.

  In a wireless transmission device that transmits visually recognizable data, such as images, when a moving image or multiple images are displayed in a regular manner, only the part that needs to be rewritten is rewritten without rewriting the entire frame. The amount of image data to be transferred can be reduced, and the time required for processing and transmission can be shortened.

  A vector scan transmission method and a transmission device using the same according to the present invention will be described with reference to the drawings.

In this embodiment, a case of connecting to a computer having display data and a liquid crystal projector for displaying the data will be described. The transmission side transmission device 100 is connected to the computer 10 and transmits data such as images, and the reception side transmission device 200 is connected to the liquid crystal projector device and receives data such as images.
FIG. 1 is a block diagram of a transmission side transmission device connected to a personal computer and transmits image data. FIG. 2 is connected to a projection display device, receives the transmitted image data, and restores the image to a displayable state. The block diagram of the receiving side power transmission apparatus which performs is shown. FIG. 3 is a block diagram showing the hardware configuration of the personal computer.

  The transmission-side transmission device 100 includes a transmission-side wireless transmission device interface terminal 110 connected to the personal computer 10, a control software storage device 120 that stores various programs and transmission data, and data such as images output from the personal computer 10. A microcomputer 130 for controlling the transmission-side wireless transmission device that controls compression, transmission of data such as images to the transceiver 150, a data compression element 140 that compresses data such as images, and transmission of compressed data And an antenna 160 for transmitting and receiving radio waves.

  The transmission-side wireless power transmission device interface terminal 110 is connected to the data supply-side interface terminal 11 of the personal computer 10 using the connector 12. At this time, not only data such as an image is supplied, but also power that can drive the transmission-side transmission device 100 is supplied. If it does in this way, power supplies, such as a battery and an alternating current power supply, will become unnecessary for the transmission side transmission apparatus 100. The transmission-side wireless transmission device control microcomputer 130 compresses data such as images input from the transmission-side wireless transmission device interface terminal 110 or transmits the compressed data to the reception-side transmission device 200. Further, when the data transmitted by the receiving side transmission device cannot be received or the received data is broken, the data is repeatedly transmitted to the receiving side transmission device. A microcomputer can also be used. The data compression element 140 compresses data such as an image. The amount of compression is arbitrarily determined according to the relationship with the transmission speed. It is also possible to use an element for compression. The control software storage device 120 stores the data compressed by the data compression element 140. In the image data, data necessary for drawing one screen is stored. The transceiver 150 transmits the compressed data to the receiving side transmission device. Further, a signal indicating whether or not the data transmitted by the receiving side transmission device has been correctly received is received. Note that the same frequency is used for the transmission frequency and the reception frequency. The antenna 160 is set so as to enhance the directivity in three directions.

  Further, the computer 10 outputs data such as an image to be displayed through a data supply side interface terminal 11 provided in the personal computer 10. The transmission-side transmission device 100 and the personal computer 10 are connected by a connector 12. A cable or the like may be used as an alternative to the connector 12.

  The receiving side transmission device 200 includes an antenna 210 that receives data from the transmission side transmission device 100, a transceiver 220 that receives data and transmits the quality of the received signal, a reception side wireless transmission control microcomputer 240, and a control software storage device 230. , A data decompressing element 250 for decompressing the compressed data, a video ram 260 for storing an amount of information necessary for rendering, a video signal converting element 270, and a receiving-side wireless transmission device interface terminal 280. The liquid crystal projector 20 has a data output side interface terminal 21. The reception-side power transmission device 200 and the liquid crystal projector 20 are connected to the reception-side wireless power transmission device interface terminal 280 and the data output-side interface terminal 21 directly via the connector 22 or using a cable or the like.

  The antenna 210 is set to have directivity in three directions. Data transmitted from the transceiver 220 and the transmission-side transmission device 100 is received. In addition, the quality of the received data is transmitted to the transmission apparatus 100 on the transmission side. The receiving side control unit 240 determines whether or not the received data has been correctly received. The data decompressed by the receiving side storage unit 230 and the data decompression unit 250 is stored. The amount to be stored is arbitrary. For example, storing data for one screen or storing the data amount of half the screen. The data decompressing element 250 decompresses the data sent after being compressed, and restores the data before being compressed. The receiving side wireless power transmission device interface terminal 280 receives power from the liquid crystal projector 20. By doing in this way, another external power supply required for driving the receiving side transmission apparatus 200 becomes unnecessary.

  Here, a state in which data stored on the video board in the personal computer 10 is transferred to the USB interface 360 is shown. The monitor 310 of the personal computer 10 is connected to the video board 320. Data about the contents to be displayed is a digital parallel signal in the video board 320. The digital parallel signal is converted by a microcomputer (CPU) 330 into a USB (Universal Serial Bus) output conversion 350 which is a digital serial signal. Further, the digital parallel signal of the video board 320 is converted into an RGB signal which is an analog parallel signal and is output to the RGB output 340.

  Next, a method for identifying image data to be transferred by the personal computer 10 on the screen will be described. The personal computer 10 referred to here is assumed to be connected to the transmission-side power transmission device 100 via the interfaces 11 and 110 due to its configuration. Further, it is assumed that the transmission-side transmission device 100 is linked to the reception-side transmission device 200 using wireless communication, and the reception-side transmission device 200 is connected to the data projection display device 20, for example, a liquid crystal projector device.

  When displaying the data, the personal computer 10 writes the data to be displayed in the video ram (display random access memory). The display device 310 of the personal computer 10 refers to the video ram and displays the value on the display device 310 of the personal computer 10. When the personal computer 10 writes to the video ram, only the changed part is written, and in the other part, a method of holding the already written value is taken. By importing the contents and address, the rewritten data can be transmitted to the other party. By sending the address and attribute (attribute) of each pixel of image data, the content to be sent can be any shape, such as a circle, ellipse, polygon, or curve. However, since the address itself becomes a huge amount of data for each pixel, it causes a reduction in image transfer speed.

  In the present embodiment, a method for rewriting the most common square or rectangular window will be described. In the case of a square or rectangle, the position can be specified by specifying the coordinates of each corner. In the rectangle, the position information necessary for partially rewriting the image is the address of the four vertices. Here, in the case of a square or rectangle, if the position information of the two vertices on the diagonal line is known, the addresses of the other two vertices can be obtained.

  When the personal computer 10 starts accessing the video ram, the personal computer 10 writes the data into a memory having the same address configuration as the video ram prepared for data transfer. Then, the addresses of the first and last pixels are stored. The first and last addresses indicate addresses related to two vertices on the diagonal line of the window to be rewritten, for example, upper left and lower right on the screen. The personal computer 10 can determine which portion of the data is on the personal computer 10 on the data receiving side by sending two addresses related to the apex attached to the compressed data.

  Next, when the personal computer 10 is equipped with a 32-bit microprocessor, the display device has XGA resolution, that is, the display area has horizontal 1024 pixels and vertical 768 pixels, and the color resolution for each pixel is 32 bits. An example will be described. 4 and 5 are schematic diagrams showing the relationship between the displayed partial image and the video ram. 4 shows a partial pixel and its area, and FIG. 5 shows a partial pixel and its memory area.

  First, regarding the pixel arrangement, the upper left corner of the display area 410 is defined as coordinates (0, 0), and the lower right corner is defined as coordinates (1023, 767). The address arrangement of the image memory is arranged on a straight line. In other words, the second row is after the first row, and the third row is after the second row. Therefore, the address of one point having the coordinates (X, Y) on the screen is represented by 1024x (Y-1) + (X-1). When the image content is changed only to a rectangular range 420 having the coordinates of the upper left vertex (X1, Y1) and the coordinates of the lower right vertex (X2, Y2) on the image memory occupied by the square 420. The first image memory address is represented by 1024x (Y1-1) + (X1-1), and the last image memory address is represented by 1024x (Y2-1) + (X-1). By sending these image addresses attached to a compressed image of a partial image that is a part of the displayed screen with coordinates (X1, Y1) (X2, Y2) as diagonal coordinates, a data transmission device on the receiving side The display position of the partial image sent can be determined. Note that the JPEG (Joint Photographic Experts Group) method with high moving image compression efficiency was used for the compression of the partial images in this embodiment. As an application of the present invention, a window is provided in a part of a computer image, and a moving image is displayed in the window to display a working scene such as a moving product. The display area 410 includes a pixel 510 having a 32-bit attribute and a 32-bit memory area 520.

  Next, a method for writing a partial image using the receiving side transmission device 200 to the projection display device 20, in this embodiment, a liquid crystal projector device will be described.

  The receiving-side power transmission device 200 is connected to the projection display device 20 via the interfaces 280 and 21. Regarding functions, the receiving-side transmission device 200 receives partial image information by radio waves from the transmitting-side transmission device 100, decompresses the received image information, and stores the decompressed image data in a control software storage device 230 that temporarily stores the information. The digital signal is converted into an analog signal while referring to the image data held in the storage device 230. The projection display device 20 has a function of displaying image data that has become an analog signal from the reception-side transmission device 200.

  The receiving side transmission device 200 is the part to be rewritten, in this embodiment, the coordinates of the upper left vertex of the rectangle are (X1, Y1), the coordinates of the vertex on the diagonal are (X2, Y2), and the coordinate information is compressed. The partial image data is received from the transmission apparatus 100 on the transmission side. The receiving side transmission device 200 separates the coordinate address information and the compressed partial image data. The partial image data is decompressed using decompression software and temporarily stored in the storage device. Next, a partial image is transplanted within the entire displayed screen.

  Next, a method for transplanting the partial image data decompressed and temporarily stored in the control software storage device to the frame memory, that is, the image memory for one screen will be described. First, the length in the horizontal direction of the decompressed partial image is represented by X2−X1 + 1. Similarly, the horizontal length is represented by Y2-Y1 + 1. In this embodiment, the number of pixels in the horizontal direction is 1,024 pixels on the condition that an XGA resolution projection display device is used. The transplant start address on the frame memory side is 1024 * (Y1-1) + (X1-1), and the transplant start address of the storage device on the temporary storage side is 0. Accordingly, in the rewriting range, if the horizontal variable is defined as x and the vertical variable is defined as y, x may be changed from X1 to X2 + 1, and y may be changed from Y1 to Y2 + 1. That is, the address (X2−X1) * (y−Y1) + (x−X1) of the storage device on the temporary storage side is ported to the address 1024 * (y−1) + (x−1) on the frame memory side. It ’s fine. Once the frame memory is rewritten, the element that converts the digital signal to the analog signal performs the conversion with reference to the value of the frame memory, so the same effect is obtained when the image changes at a constant cycle and the moving image is displayed. It is done.

  A method of distinguishing and displaying still images and moving images in a display environment in which still images and moving images are mixed will be described. FIG. 6 and FIG. 7 show the physical relationship between the transmission-side transmission device 100 and the personal computer 10 and the physical relationship between the reception-side transmission device 200 and the projection display device 20.

  A partial image 420 is displayed in the display area 410 displayed on the display device 310 of the personal computer 10. The image displayed on the display device 310 is transmitted to the reception-side wireless transmission device 200 via the transmission-side wireless transmission device 100. The image transmitted to the reception-side wireless power transmission device 200 is received by the reception-side wireless power transmission device 200 and projected onto the screen 700 from the projection display device 20.

  Here, when the still image is transmitted using the wireless data transmission devices 100 and 200, there are a method of continuously transmitting an image and a method of transmitting only an image instructed by the operator of the device, a so-called one-capture method. Two are common. It is assumed that the wireless data transmission devices 100 and 200 of this embodiment adopt a one-capture method. In this method, an operator generates an interrupt using a key, a mouse, or the like, and the interrupt activates the image transfer software. Therefore, when the moving image is activated, the display is started by the input of the operator's key or mouse. However, in the case of a moving image, unlike the case of a still image, rewriting is repeatedly performed on the same screen. Therefore, an interrupt must be generated each time an image is redrawn, and the rewritten image must be transmitted. Also, the transmission of the image must be stopped when the moving image is over.

  Next, FIG. 8 shows a method of processing data transmitted by the transmission apparatus 100 on the transmission side. When the personal computer 10 goes to write a moving image on the attached display device 310, the central processing unit of the personal computer 10 performs a process of writing the video data after decompressing the image data stored in the storage medium. Do. This is possible by a method of starting image transfer software using an interrupt generated when this processing is performed.

  As for the moving image transfer method, activation related to the transfer of the moving image initial screen is activated by an operator's key operation or a mouse operation (step 301). When an interrupt is generated in the central control unit of the personal computer 10 depending on whether the key is pressed or the mouse is pressed (step 302), the image transfer software is started by the interrupt (step 303). When the software is included in the external storage medium, the software is ready to be executed by the central processing unit. In other words, if it is loaded into a memory for execution or is already loaded into a memory that can be executed by the central processing unit, it means that the software is put into execution.

  Next, after the personal computer 10 decompresses the moving image, the decompressed partial image is written to the video ram (step 304). When the decompressed partial image is written into the video ram, an interrupt occurs (step 305), and when this interrupt occurs, the image transfer software starts processing (step 306). First, the image transfer software extracts the first address written in the video ram (step 307) and writes the value to the designated memory (step 308). At the same time, the value written in the video ram is written in the memory for compression processing (step 309). Each time the central processing unit goes to write partial image data to the video ram, the image transfer software continuously writes to the compression memory (step 310). When the writing of one frame is completed, the image transfer software writes the address of the last image data of one frame in the designated memory (step 311). Next, the image transfer software compresses the partial image 420 stored in the compression memory (step 312). The compressed partial image data 420 has a data address different from that of the image data before compression. In this embodiment, the JPEG method is used as an image compression method. The image transfer software informs the transmitting side transmission device 20 that the image compression has been completed via the interfaces 11 and 110 (step 313), and transfers control for transferring the compressed partial image data to the interface controller (step 313). Step 314).

  On the other hand, the interface controller to which the control has been transferred transfers the compressed image data and the first address and the last address of the partial image 420 to the transmission side wireless device 100 (step 315). The transmission side transmission apparatus 100 temporarily stores the compressed data of the partial image 420 received from the interface and the first and last two addresses in the memory 120 in the transmission side transmission apparatus 100 (step 316). The transmission-side transmission device 100 performs high-frequency modulation on the partial image 420 and the address data stored in the memory 120, and transmits them to the reception-side transmission device 200 (step 317). The image transfer software waits for an interrupt that occurs when the central processing unit goes to write the next partial image to the video ram (step 318).

  Next, FIG. 9 shows a method for processing data transmitted from the transmission apparatus 100 on the transmission side. The compressed partial image data 420 and address data are received from the transmission apparatus 100 (step 321). The receiving side transmission apparatus 200 demodulates the data (step 322) and stores it in the temporary storage memory 230 (step 323). The compressed partial image data 420 is separated from the address data (step 324) and decompressed by decompression software (step 325). On the other hand, the address data is divided into start address coordinates (X1, Y1) and end address coordinates (X2, Y2), and is stored in the temporary storage memory 70 (step 326). The partial image data decompressed by the decompression software is transplanted into the range of the rectangle (X1, Y1, X2, Y2) surrounded by the start address and the end address (step 327).

  The image 410 of one frame including the transplanted partial image 420 is converted into an analog signal by the video signal converter (step 328), and transferred to the projection display device 20 through the interfaces 280 and 21 (step 329).

Block diagram of the transmitting device OLE_LINK1 block OLE_LINK1 diagram of the receiving side transmission device Block diagram showing the structure of a personal computer The figure which shows the partial image concerning the data transfer of a partial image, and its area | region A diagram showing pixels and their memory areas related to partial image data transfer Transmission side hardware configuration diagram for partial image transfer Receiving-side hardware configuration diagram for displaying partial images Flowchart on the transmission side for partial image transfer Flowchart on the receiving side for partial image transfer

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Personal computer 20 Projection display apparatus 50 Central control apparatus 60 Interface controller 70 Memory 100 for temporary storage Transmission side wireless transmission apparatus 200 Reception side wireless transmission apparatus

Claims (5)

Of the images drawn in the display area where the image can be displayed to the maximum extent, the partial area in the partial area indicating the area of the image that needs to be rewritten from the currently displayed state in the display area Vector scan transmission method that transmits the address and attributes of 2. The vector scan transmission according to claim 1, wherein a receiving memory has the same address configuration as a video ram for drawing the display area, receives the data of the partial area, and rewrites and displays only the data of the partial area. Method. 3. The point according to claim 1, wherein when the partial area is a quadrangle, two points on the diagonal of the quadrangle are selected as a start point indicating the start of the partial area and an end point indicating the end of the partial area. Vector scan transmission method. The vector scan transmission method according to claim 1, wherein the image displayed in the partial area is a moving image. A power transmission device that displays an image by the method according to claim 1.

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