JP2006209552A - Transfer device, image transfer system, control method of transfer device, control program of transfer device and recording medium with control program of transfer device recorded thereon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a transfer device capable of efficiently transferring image data of an optional rectangular image in a simpler device configuration and with a small amount of operations. <P>SOLUTION: A transfer controller of this invention is provided with a parameter determining part 23 for calculating a start parameter 50 showing a storage pattern of image data in a VRAM (video random access memory) 6 on the basis of start point coordinates 31 and end point coordinates 32 in a display area which regulate the shape of a rectangular image to be drawn and a row size 34 of a VRAM 1 showing the range of a memory area corresponding to the arrangement of horizontal pixels in the entire display area, a memory transfer starting part 22 for instructing image data transfer, and a DMA (direct memory access) transferring part 21 for transferring the image data to a display device on the basis of the start parameter 50 in response to an instruction of the memory transfer starting part 22. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transfer device, an image transfer system, a transfer device control method, and a transfer device control program that transfer rectangular image information from a storage device that holds rectangular image information for displaying a rectangular image region to the display device. And a recording medium on which a control program for the transfer device is recorded.

  Conventionally, DMA (direct memory access) transfer has been widely used as a method of transferring video or image data given from the outside to video random access memory (VRAM).

  As a system for realizing the transfer of video or image data by the DMA transfer described above, there is a computer system 100 using a DMA controller (hereinafter referred to as DMAC) 155 as shown in FIG. FIG. 6 is a block diagram showing a schematic configuration of a computer system 100 using the DMAC 155.

  As shown in FIG. 6, the computer system 100 using the DMAC 155 includes three VRAMs 151R, 151G, and 151B. Each of these VRAMs 151R, 151G, and 151B stores color data Dr, Dg, and Db that are hue-separated into red (R), green (G), and blue (B).

  In this computer system 100, the DMAC 155 acquires the right to use the address bus 153, the data bus 152, and the control bus 154 from the CPU 159, and assigns the color from each of the three video memories 151R, 151G, and 151B to the display VRAM. Data Dr, Dg, Db is transferred. The color data Dr, Dg, and Db transferred in this way are transmitted to the monitor control unit 157 through the VRAMs 156R, 156G, and 156B, and an image is displayed on the monitor 158.

  When the image data is transferred by the DMAC 155, the CPU 159 assigns the display start addresses in the R component VRAM (VRAM 151R), the G component VRAM (VRAM 151G), and the B component VRAM (VRAM 151B) to the DMAC 155. Sequentially. Then, the DMAC 155 sequentially transfers the color data Dr, Dg, Db for each received start address to the display VRAM.

  That is, in the computer system 100 described above, the CPU 159 calculates a display start address for each color data. The CPU 159 needs to set the respective display start addresses in the DMAC 155.

  For this reason, for example, when transferring image data stored in the VRAM 151R, 151G, or 151B, if the address of the image data stored in the transfer source VARM is not continuous, the image is generated by one start address. Data cannot be transferred at once. That is, the CPU 159 needs to transfer a plurality of instructions for setting the display start address to the DMA controller 155.

  Therefore, when the CPU 159 needs to instruct the DMAC 155 for an address for each area in which image data is stored and perform the transfer, there is a problem that the data transfer process becomes complicated.

  Therefore, in order to increase the processing efficiency of data transfer, Patent Document 1 discloses a moving image data transfer apparatus that calculates a data transfer destination address in the DMAC and can perform DMA transfer at high speed.

  That is, the moving image data transfer apparatus includes a multiplier that multiplies the addition address value and the count value in the vertical direction, a first adder that adds the offset address and the multiplication result of the multiplier, and the first addition. A second adder that adds the addition result of the adder and the count value of the horizontal counter unit, and the addition result of the second adder and the area start address of each RGB component, A DMA controller having a third adder for calculating an access address;

  Further, in Patent Document 2, the relationship between the address input value and the converted address output value is set between the DMA transfer control device and the image memory so as to skip the extra area other than the image data storage portion on the image memory. A still image processing apparatus having an address conversion table is disclosed.

  Further, Patent Document 3 includes a plurality of sets of DMA setting register sets in which a start address value for performing DMA transfer and a transfer count value indicating a data transfer width are set, and the contents of these register sets are arranged in a predetermined order. A DMA data transfer apparatus that sequentially references and executes a plurality of DMA transfers is disclosed.

In this DMA data transfer device, when data transfer is completed, the next data transfer can be started with reference to this register set.
Japanese Patent Laid-Open No. 6-332843 (published December 2, 1994) JP-A-5-158866 (released on June 25, 1993) Japanese Patent Laid-Open No. 10-154125 (released on June 9, 1998)

  However, the configuration of Patent Document 1 has a problem that the process of calculating the address of the video data corresponding to the moving image area in the display area becomes complicated. That is, in the configuration shown in Patent Document 1, every time 8-bit binary data of each RGB color is DMA-transferred, the number of horizontal counters indicating the positions measured from the left end point of each scanning line is increased, and the video data It is configured to calculate an address. Therefore, in the configuration of Patent Document 1, the amount of calculation for calculating an address increases as the number of pixels forming the moving image area increases.

  Further, the configuration shown in Patent Document 2 has a problem that it can be used only for transferring image data in which a drawing area is fixed. That is, in the still image processing apparatus disclosed in Patent Document 2, the address conversion unit can convert the input address so that the address is continuous from the start address only for image data of a predetermined shape. . Therefore, in the configuration shown in Patent Document 2, it can be used only for displaying a drawing having a predetermined shape recorded by the address conversion unit.

  Further, in the configuration shown in Patent Document 3, a register for storing the start address of this area and the transfer width of this area must be prepared in accordance with the number of areas in the memory where the data to be transferred is a continuous address. Don't be. That is, it is necessary to prepare registers in advance for the number of areas that are the continuous addresses before data transfer. For this reason, it is necessary to prepare a large number of registers in advance in anticipation of an increase in the number of areas where addresses are continuous, resulting in a problem that the device configuration becomes complicated.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to efficiently transfer image data of an arbitrary rectangular image area with a simpler apparatus configuration and a small amount of calculation. A transfer apparatus, an image transfer system, a transfer apparatus control method, a transfer apparatus control program, and a recording medium on which the transfer apparatus control program is recorded.

  In order to solve the above problems, a transfer device according to the present invention is a transfer device that transfers rectangular image information from a storage device that holds rectangular image information for displaying a rectangular image region to a display device, When the horizontal direction in the display area of the display device is the x coordinate and the vertical direction is the y coordinate, the pixel in the display area specified by the x coordinate and the y coordinate, and the rectangular image information displayed in the pixel The addresses in the storage area of the storage device to be stored are associated with each other, and the addresses corresponding to pixels adjacent in the horizontal direction are consecutive in the order of reading, and are the starting points that are the end points of the diagonal lines of the rectangular image area Based on the coordinates and end point coordinates and the display range information corresponding to the number of pixels in the horizontal direction in the entire display area, the storage pattern of the rectangular image information in the storage device is shown. A calculation means for calculating payment pattern information; an instruction means for instructing the transfer means to transfer rectangular image information based on the storage pattern information calculated by the calculation means; and an instruction from the instruction means And a transfer means for transferring the rectangular image information to a display device based on the storage pattern information.

  By the way, the rectangular image area has a rectangular shape parallel to each side of the display area, and a drawing range of the rectangular image area is a pixel between a horizontal y coordinate and another y coordinate in the display area. Are arranged in combination in the vertical direction. For this reason, the rectangular image region can be defined by the start point coordinates and the end point coordinates.

  Also, each pixel in the display area is associated with an address for storing rectangular image information displayed in the pixel, and the storage area between the pixels adjacent in the horizontal direction is an address that is continuous in the readout order. It has become.

  Therefore, in the storage device, rectangular image information corresponding to the number of pixels in the horizontal direction of the rectangular image area is stored in a storage area of continuous addresses. Then, a specific storage pattern in which the storage areas serving as consecutive addresses are arranged at regular intervals is shown.

  According to the above configuration, the calculation means can calculate storage pattern information indicating a storage pattern of the rectangular image information in the storage device based on the start point coordinates and end point coordinates, the start address, and display range information. .

  That is, the calculation means can know the address of the storage area where the reading of the rectangular image information is started from the start point coordinates. Further, the calculation means can acquire information corresponding to the number of pixels in the horizontal direction of the rectangular image area from the value of the x coordinate of the start point coordinate and the end point coordinate.

  Further, the calculation means can determine the number of pixels in the vertical arrangement in the rectangular image area from the y-coordinate values of the start point coordinate and the end point coordinate.

  Further, the calculating means calculates the next horizontal direction from the horizontal pixel arrangement of the rectangular image area based on the information corresponding to the horizontal pixel number of the rectangular image area calculated above and the display range information. It is possible to obtain information corresponding to the number of pixels until the pixel arrangement.

  In this way, the calculation means can determine the storage pattern in the storage device of the rectangular image information of the rectangular image area defined by the start point coordinates and the end point coordinates.

  The calculation performed by the calculation means to calculate the storage pattern is a simple four arithmetic operation, and the amount of information used for the calculation is small, so the storage pattern information can be calculated with a small calculation amount. it can.

  The transfer device according to the present invention is configured such that the transfer means can transfer the rectangular image information from the storage device to the display device based on the storage pattern information in response to an instruction from the instruction means. For this reason, the transfer apparatus according to the present invention does not need to acquire the head address of this area for each storage area where the addresses are continuous. In particular, when the transfer means is realized by, for example, DMAC, it is not necessary to inquire the CPU for the address for storing the rectangular image information during the transfer of the image data, so the rectangular image information in the rectangular image area is transferred at high speed. can do.

  Furthermore, the storage pattern of the rectangular image information in the storage device calculated by the calculation means corresponds to the rectangular image information of the rectangular image area defined by the start point coordinates and the end point coordinates. That is, when the user arbitrarily designates the start point coordinate and the end point coordinate, the transfer device can execute transfer of rectangular image information corresponding to a rectangular image region having an arbitrary size.

  In addition, the transfer apparatus according to the present invention may calculate the storage pattern information described above before transferring the rectangular image information, and store the calculated information in, for example, a register. Therefore, unlike the above-described Patent Document 3, the transfer device does not need to prepare registers for the number of storage areas that are consecutive addresses, and thus can solve the problem of complicated device configuration.

  Therefore, the transfer device according to the present invention has an effect that image data in an arbitrary rectangular image area can be efficiently transferred with a small amount of calculation.

  In the transfer device according to the present invention, in the configuration described above, the storage pattern information includes an address read first in the storage area storing the rectangular image information, and a horizontal pixel in the drawn rectangular image area. From the drawing range information corresponding to the number, the pixel column number information indicating the number of pixels in the vertical direction included in the rectangular image region, and the pixel column that is an array of pixels in the horizontal direction in the rectangular image region, the next pixel It is preferable to include interval range information corresponding to the number of pixels between the columns.

  That is, according to the above configuration, the storage pattern information is clearly defined by the address read first in the storage area range storing the rectangular image information, the drawing range information, the pixel column number information, and the interval range information. be able to.

  As described above, the transfer device according to the present invention can clearly obtain a storage pattern indicating a storage position of image data to be transferred when rectangular image information is transferred. Therefore, the transfer device can efficiently transfer image data with reference to this storage pattern.

  In the transfer device according to the present invention, in the configuration described above, the display device includes a buffer for temporarily storing rectangular image information to be displayed, and the transfer means stores the rectangular image information stored in the storage device. May be transferred to the buffer.

  That is, the transfer device according to the present invention is configured to transfer the rectangular image information stored in the storage device to the buffer provided in the display device. Therefore, the rectangular image information can be smoothly transferred without considering the overflow of the transferred rectangular image information on the display device side.

  Further, in the transfer device according to the present invention, in the configuration described above, the transfer means acquires the rectangular image information from the CPU that controls various processes of the transfer device without acquiring the bus use right via the CPU. It is preferably configured to transfer to a display device.

  The transfer device according to the present invention realizes high-speed transfer of rectangular image information without imposing a load on the CPU when the transfer means is configured to transfer rectangular image information to the display device without going through the CPU. Can do.

  In order to solve the above-described problem, a transfer device control method according to the present invention transfers a rectangular image information from a storage device that holds the rectangular image information for displaying a rectangular image region to the display device. And a pixel in the display area specified by the x coordinate and the y coordinate when the horizontal direction in the display area of the display device is the x coordinate and the vertical direction is the y coordinate, and the pixel The addresses in the storage area of the storage device that store the rectangular image information to be displayed are associated with each other, and the addresses corresponding to pixels adjacent in the horizontal direction are consecutive in the order of reading, and the rectangular image area A rectangular image in the storage device based on the start point coordinates and end point coordinates which are the end points of the diagonal line and the display range information corresponding to the number of pixels in the horizontal direction in the entire display area In accordance with a step of calculating storage pattern information indicating a storage pattern of information, a step of instructing to transfer rectangular image information based on the calculated storage pattern information, and an instruction of transferring the rectangular image information And transferring the rectangular image information to the display device based on the storage pattern information.

  According to the above method, the storage pattern information indicating the storage pattern of the rectangular image information in the storage device is calculated based on the start point coordinates and the end point coordinates and the display range information corresponding to the number of pixels in the horizontal direction in the entire display area. be able to.

  That is, the transfer device control method according to the present invention can determine the storage pattern in the storage device of the rectangular image information for drawing the rectangular image area defined by the start point coordinates and the end point coordinates. In addition, the calculation performed by the above method for calculating the storage pattern is a simple four arithmetic operation, and since the amount of information used for the calculation is small, the storage pattern information can be calculated with a small calculation amount. .

  Further, the calculated storage pattern of the rectangular image information in the storage device corresponds to the rectangular image information of the rectangular image area defined by the start point coordinates and the end point coordinates. That is, when the user arbitrarily designates the start point coordinates and the end point coordinates, the transfer device control method can execute transfer of rectangular image information corresponding to an arbitrarily large rectangular image region.

  In the transfer device control method according to the present invention, the rectangular image information can be transferred from the storage device to the display device based on the storage pattern information obtained above. For this reason, in the control method of the transfer apparatus according to the present invention, it is not necessary to acquire the head address for each storage area where addresses are continuous during transfer of rectangular image data.

  Therefore, the control of the transfer apparatus according to the present invention has an effect that image data of an arbitrary rectangular image area can be efficiently transferred with a small amount of calculation.

  An image transfer system according to the present invention includes the transfer device described above, a storage device that holds rectangular image information for displaying a rectangular image region, and a display device that displays the rectangular image information. .

  Therefore, the rectangular image information stored in the image device can be efficiently transferred to the display device, and the rectangular image area based on the rectangular image information can be displayed on the display device.

  The transfer device may be realized by a computer. In this case, the computer reads the control program for the transfer device that causes the transfer device to be realized by the computer by operating the computer as each of the means. Possible recording media also fall within the scope of the present invention.

  As described above, the transfer device according to the present invention is a transfer device that transfers rectangular image information to a display device from a storage device that holds rectangular image information for displaying a rectangular image region. When the horizontal direction in the display area is x-coordinate and the vertical direction is y-coordinate, the pixels in the display area specified by the x-coordinate and y-coordinate and rectangular image information to be displayed in the pixels are stored. Addresses in the storage area of the storage device are associated with each other, and the addresses corresponding to pixels adjacent in the horizontal direction are consecutive in the order of reading, and start point coordinates and end points that are diagonal end points of the rectangular image area A storage pattern indicating a storage pattern of rectangular image information in the storage device based on coordinates and display range information corresponding to the number of horizontal pixels in the entire display area A calculation means for calculating information, an instruction means for instructing the transfer means to transfer rectangular image information based on the storage pattern information calculated by the calculation means, and an instruction from the instruction means And transfer means for transferring the rectangular image information to a display device based on the storage pattern information.

  Therefore, the transfer device according to the present invention has an effect that image data in an arbitrary rectangular image area can be efficiently transferred with a small amount of calculation.

  In addition, as described above, the control method of the transfer device according to the present invention obtains the rectangular image information from the storage device that holds the rectangular image information for displaying the rectangular image region in order to solve the above-described problem. A method for controlling a transfer device for transfer to a display device, wherein the display region is specified by the x coordinate and the y coordinate when the horizontal direction in the display region of the display device is an x coordinate and the vertical direction is a y coordinate. Are associated with addresses in the storage area of the storage device for storing rectangular image information to be displayed in the pixels, and the addresses corresponding to pixels adjacent in the horizontal direction are consecutive in the order of reading. Based on the start point coordinates and end point coordinates which are the end points of the diagonal line of the rectangular image area, and the display range information corresponding to the number of pixels in the horizontal direction in the entire display area. A step of calculating storage pattern information indicating a storage pattern of rectangular image information at a position, a step of instructing transfer of rectangular image information based on the calculated storage pattern information, and a step of transferring the rectangular image information A step of transferring rectangular image information to a display device based on the stored pattern information in response to an instruction.

  Therefore, the control of the transfer apparatus according to the present invention has an effect that image data of an arbitrary rectangular image area can be efficiently transferred with a small amount of calculation.

  An embodiment of the present invention will be described below with reference to FIGS. That is, the LCD (Liquid Crystal Display) display system 1 (image transfer system) according to the present embodiment is based on the image data (image information) stored in the VRAM 6 (storage device), and the rectangular image area ( A rectangular image 70) is displayed.

  As shown in FIG. 2, the LCD display system 1 includes a display device 13, a transfer control device (transfer device) 5, and a VRAM 6. FIG. 2 is a diagram showing an example of a schematic configuration of the LCD display system 1 according to the present embodiment.

  When the display device 13 receives the image data held in the VRAM 6 via the transfer control device 5, the display device 13 performs display based on the image data. The display device 13 includes an LCD display unit 2, a display control unit 3, and an LCD display buffer (buffer) 4.

  The VRAM 6 is a so-called video memory (dual port DRAM) and stores input image data for each pixel.

  The transfer control device 5 reads image data stored in the VRAM 6 in accordance with an instruction from the user, and DMA-transfers it to the LCD display buffer 4 provided in the display device 13. A detailed description of the transfer control device 5 will be described later.

  The LCD display buffer 4 temporarily stores the image data transferred from the VRAM 6 and adjusts the display timing of the image data on the LCD display unit 2. The LCD display buffer 4 also adjusts so that the image data transferred by the transfer control device 5 does not overflow.

  The display control unit 3 performs display processing so that the image data temporarily stored in the LCD display buffer 4 is displayed on the LCD display unit 2. The display processing on the LCD display unit 2 by the display control unit 3 is performed according to the screen update cycle of the LCD display unit 2.

  The LCD display unit 2 is a display device that can display a rectangular image region (rectangular image 70) based on image data on a screen. In other words, the LCD display unit 2 is a display device using liquid crystal. A special liquid is sealed between two glass plates, and a voltage is applied to change the direction of liquid crystal molecules, thereby increasing or decreasing the light transmittance. Thus, the image is displayed.

  As described above, in the LCD display system 1 according to the present embodiment, the transfer control device 5 reads the image data stored in the VRAM 6 and DMA-transfers it to the LCD display buffer 4 in accordance with an instruction from the user. Then, the image data temporarily stored in the LCD display buffer 4 is transferred to the LCD display unit 2 and displayed by the LCD display unit 2 in accordance with an instruction from the display control unit 3.

  Next, with reference to FIG. 3, the structure of the main part of the LCD display system 1 according to the present embodiment will be described. Note that FIG. 3 is a diagram showing a main configuration of the LCD display system 1 according to the present embodiment. And in this figure, the same code | symbol is attached | subjected to the same member demonstrated in FIG. 2, and the description is abbreviate | omitted.

  As shown in FIG. 3, the LCD display system 1 according to the present embodiment includes an arbitration unit 7, a DMAC 9, a CPU 10, a ROM 11, and an SDRAM 12, and each is connected to a system bus 8.

  The DMAC 9 DMA-transfers the image data stored in the VRAM 6 to the LCD display buffer 4 in response to a transfer instruction from the CPU 10. The arbitration unit 7 receives a request for using the system bus 8 from the DMAC 9 and requests the CPU 10 for permission to use the system bus 8.

  That is, the DMAC 9 instructs the arbitration unit 7 to request the CPU 10 to use the system bus 8 in accordance with an instruction from the CPU 10. When the right to use the system bus 8 is approved by the CPU 10, the DMAC 9 reads the image data from the VRAM 6 through the system bus 8 and transfers it to the LCD display buffer 4 through the system bus 8.

  The CPU 10 uses the system bus 8 to perform various controls of each member of the transfer control device 5. That is, the ROM 11 stores a program, and the CPU 10 reads the program to the SDRAM 12 and executes the read program to realize the various controls.

(Schematic configuration of transfer control device)
Here, a schematic configuration of the transfer control device 5 according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing an example of a main configuration of the transfer control device 5 provided in the LCD display system 1 according to the present embodiment.

  That is, as shown in FIG. 1, the transfer control device 5 includes a DMA transfer unit (transfer unit) 21, a memory transfer start unit (instruction unit) 22, a parameter determination unit (calculation unit) 23, a setting information storage unit 24, A start parameter storage unit 25 and a transfer information storage unit 26 are provided.

  The DMA transfer unit 21 transfers the image data stored in the VRAM 6 to the LCD display buffer 4 in response to an instruction from the memory transfer start unit 22. This functional block is realized by the DMAC 9 reading and executing a program from a storage medium such as the ROM 11. That is, the DMAC 9 according to the present embodiment is different from the normal DMAC in that it includes a DMA transfer unit 21 that is realized as a functional block.

  The DMA transfer unit 21 obtains various information stored in the transfer information storage unit 26 based on the start parameter (storage pattern information) 50 stored in the start parameter storage unit 25 and is stored in the memory area 80 of the VRAM 6. The received image data is transferred to the LCD display buffer 4.

  The parameter determination unit 23 obtains various types of information stored in the setting information storage unit 24 as setting information in response to an image data transfer instruction from the user, and calculates a start parameter 50. The parameter determination unit 23 stores the calculated start parameter 50 in the start parameter storage unit 25.

  The start parameter 50 includes a transfer start address 41, an image line size 42, an offset amount 43, and a loop count 44. A method for calculating various information included in the start parameter 50 will be described later. The parameter determination unit 23 calculates a start parameter and notifies the memory transfer start unit 22 of an image data transfer instruction.

  When the memory transfer start unit 22 receives a transfer instruction of image data from the user via the parameter determination unit 23, the memory transfer start unit 22 transfers the image data stored in the VRAM 6 to the LCD display buffer 4 to the DMA transfer unit 21. It is instructed to do.

  Note that the functional blocks shown as the memory transfer start unit 22 and the parameter determination unit 23 are realized by the CPU 10 reading and executing a program from a storage medium such as the ROM 11.

  The setting information storage unit 24 is a readable and writable nonvolatile recording medium, and is realized by a memory such as the SDRAM 12, for example. The start parameter storage unit 25 and the transfer information storage unit 26 are realized by internal registers provided in the DMAC 9.

  The setting information storage unit 24 includes a start point coordinate 31 (xs, ys) and an end point coordinate 32 (xe, ye) of the image displayed on the LCD display unit 2, a memory start address 33 in the memory area 80 of the VRAM 6, and the VRAM1. Includes line size.

  The start point coordinates 31 and the end point coordinates 32 are coordinates that define the shape of the rectangular image 70 to be drawn. In the present embodiment, the start point coordinates 31 are coordinates for specifying a pixel corresponding to a memory area in the VRAM 6 from which the transfer control device 5 starts reading image data. Further, the end coordinates 32 are coordinates for specifying a pixel corresponding to the memory area that is finally read by the transfer control device 5.

  The start point coordinates 31 and the end point coordinates 32 are input by designating a drawing position where the user desires to draw the rectangular image 70 by an input means (not shown) such as a mouse, a keyboard, or a numeric keypad. The coordinates designated by the user are stored in the setting information storage unit 24 as a start point coordinate 31 and an end point coordinate 32, respectively.

  More specifically, in the present embodiment, the starting point coordinates 31 are the upper left vertex coordinates of the rectangular image 70 drawn in the display area of the LCD display unit 2 as shown in FIG. The end point coordinate 32 is the lower right vertex coordinate of the rectangular image 70. That is, assuming that the upper left vertex of the display area of the LCD display unit 2 is the origin, the point (xs, ys) closest to the origin (0, 0) in the rectangular image 70 is the start point coordinate 31. The point (xe, ye) at the farthest distance from the origin is the end point coordinate 32.

  FIG. 4 is a diagram showing a correspondence relationship between the display area of the LCD display unit 2 and the memory area 80 of the VRAM 6. In this embodiment, as shown in FIG. 4, it is assumed that one address in the memory area 80 of the VRAM 6 corresponds to one pixel in the display area.

  In addition, the address of the memory area corresponding to the pixel including the origin (0, 0) in the display area is the start address in the memory area 80, and the pixel from the pixel including the origin to the horizontal direction (x-axis direction) The addresses of the corresponding memory areas are assigned so as to increase in order. Note that each pixel is specified by the x and y coordinates of the upper left point position of each pixel.

  The memory start address 33 is a head address in the memory area 80 of the VRAM 6 corresponding to each pixel in the entire display area of the LCD display unit 2. That is, the memory start address 33 stores image data to be displayed at a pixel specified by an origin (0, 0) coordinate that is an intersection of the x axis and the y axis in the display area of the LCD display unit 2 in FIG. This is an address that designates a memory area 80 for the purpose. The DMA transfer unit 21 according to the present embodiment is configured to sequentially read data from the memory area to which the memory start address 33 is assigned. Therefore, unless otherwise specified, the DMA transfer unit 21 sequentially reads data from the memory start address 33.

  The memory start address 33 is information used to calculate a transfer start address 41, which will be described later. Particularly, for example, when the memory start address 33 is an address that is always designated as address 0. This information is not required.

  The VRAM 1 row size (display range information) 34 is assigned to image data displayed by the arrangement (pixel arrangement) of pixels arranged in the horizontal direction (horizontal axis; x-axis direction) of the display area. This is the number of bits (bytes) in the memory area of the VRAM 6. That is, the storage capacity of the memory area of the VRAM 6 corresponding to the display area in the range indicated by A in FIG.

  That is, in FIG. 4, each pixel in the display area of the LCD display unit 2 is indicated by a square, and these squares correspond to one address assigned to the memory area of the VRAM 6. Then, the memory area address corresponding to the pixel located at the intersection of the x-axis and the y-axis in FIG. Addresses are assigned in the order of the pixels arranged in the x-axis direction from the cell corresponding to the memory start address 33. Note that the memory start address 33 is represented as “xxxxh” in FIG.

  In each memory area corresponding to one row of pixels (A area) in the x-axis direction, addresses are continuous. Further, consecutive addresses are assigned to the first pixel in the next cell line after the line feed and the pixel indicated as the last cell in the previous line.

  The order in which data is read by the DMA transfer unit 21 follows the order of addresses in the memory area.

  The start parameter storage unit 25 includes a start parameter 50 that is information obtained as a result of calculation by the parameter determination unit 23 based on each information stored in the setting information storage unit 24. The start parameter storage unit 25 includes, as start parameters 50, a transfer start address 41, an image line size 42, an offset amount 43, and a loop count 44.

  The transfer start address 41 is an address assigned to a memory area where the DMA transfer unit 21 actually starts reading.

  The image one-line size (drawing range information) 42 is assigned to store image data corresponding to the arrangement of pixels for one line arranged in the horizontal direction of the rectangular image 70 to be drawn. The number of bits (bytes) in the memory area. That is, it is the number of bits (bytes) indicating the storage capacity in the VRAM 6 allocated for storing the image data corresponding to the area B in FIG.

  The offset amount (interval range information) 43 is information indicating an address difference between image data stored in the memory area of the VRAM 6. That is, the offset amount 43 indicates the difference between the address of the memory area corresponding to the last pixel in the horizontal pixel array in the rectangular image 70 and the address corresponding to the first pixel in the pixel array in the next row. Information.

  More specifically, for example, the storage capacity corresponds to the number of pixels in a range from a pixel specified by coordinates (xe, ys) to a pixel preceding the pixel specified by coordinates (xs, yt).

  The number of loops (pixel column number information) 44 is a value indicating how many times the arrangement of pixels corresponding to the image one-line size 42 is combined. In other words, the drawn rectangular image 70 can be formed by combining a plurality of pixel arrangements corresponding to the image one-line size 42 in the vertical direction (y-axis direction). The number of loops is the number of combinations, that is, the number of repetitions of the pixel arrangement range corresponding to the one-line size 42 of the image.

  The transfer information storage unit 26 includes a transfer source address 45 and a current loop count 46.

  The transfer source address 45 is a head address in the memory area range in which the image data transferred by the transfer control device 5 is stored.

  In other words, the DMA transfer unit 21 according to the present embodiment is configured to read from the VRAM 6 for each image data corresponding to an image line size of 42 minutes, and transfer it to the LCD display buffer 4. In other words, the image data to be drawn is transferred for each image data stored in the memory area corresponding to one row of pixels in the x-axis direction.

  The addresses of memory areas for storing image data corresponding to the size of one line of the image are assigned so as to be continuous.

  Therefore, the DMA transfer unit 21 separates the start address in the memory area range for storing the image data corresponding to the image one-line size 42 minutes and the amount of image data to be transferred at one time (that is, the image one-line size 42). For example, the image data for one time required for the LCD display buffer 4 can be transferred.

  The current loop count 46 indicates the current read count of pixel data corresponding to an image line size of 42 minutes. That is, when the number of loops 44 is 2, the image data corresponding to the two rows of pixels displaying the rectangular image 70 is read from the VRAM 6 and transferred.

  By the way, between memory areas storing image data corresponding to one line of the rectangular image 70, the addresses are not continuous between different lines. For this reason, normally, the DMAC cannot read image data spanning different rows continuously from the VRAM 6 at a time, but reads them row by row. As described above, when image data is read line by line, the DMAC must inquire the CPU about the head address in the memory area in which the image data of each line is stored.

  However, in the transfer control device 5 according to the present embodiment, the DMA transfer unit 21 in the DMAC 9 performs the transfer of the image data based on the transfer start address 41, the image 1 row size 42, the offset amount 43, and the loop count 44. The transfer source address 45 and the current loop count 46 are obtained. Then, the image data of the rectangular image 70 is transferred from the VRAM 6 to the LCD display buffer 4 by using the obtained transfer source address 45 and the current loop count 46.

  Hereafter, details of the DMA transfer processing of the image data from the VRAM 6 to the LCD display buffer 4 by the transfer control device 5 will be described with reference to FIG. 4 and FIG. 5 described above. FIG. 5 is a flowchart showing the DMA transfer process.

(Image data DMA transfer processing)
First, it is assumed that the image data to be transferred is data of a rectangular image area (rectangular image 70), and the information amount of each pixel constituting the rectangular image 70 is 1 byte. In the memory area 80 of the VRAM 6, it is assumed that 1-byte information is stored in the memory area specified by one address. Accordingly, image data for one pixel can be stored in the memory area of the VRAM 6 designated by one address.

  The memory start address 33 of the VRAM 6 starts from address 0. That is, the memory start address 33 is an address that designates a memory area of the VRAM 6 for storing data of the intersection (0, 0) coordinates of the x axis and the y axis in the display area of the LCD display unit 2 in FIG. is there.

  Further, the start point coordinates 31 in the image data are the end portions on the x-axis direction side of the left side in the rectangular image 70 shown in FIG. 4, that is, the positions indicated by the coordinates (xs, ys), and the end point coordinates 32 are the rectangular image. The position on the diagonal line from the start point coordinate 31 in 70, that is, the position indicated by (xe, ye), which is the vertex coordinate not adjacent to the start point coordinate 31.

  First, the user sets the start point coordinates 31 and the end point coordinates 32 of the image of the rectangular area in the setting information storage unit 24 (step S11, hereinafter referred to as S11). In addition, the user instructs the parameter determination unit 23 to transfer image data.

  In response to the instruction from the user, the parameter determination unit 23 performs transfer based on the start point coordinates 31, end point coordinates 32, memory start address 33, and VRAM 1 row size 34 information stored in the setting information storage unit 24. A start address 41, an image line size 42, and a loop count 44 are calculated (S12).

  That is, the parameter determination unit 23 obtains the transfer start address 41 by calculation shown in the following formula (1).

Transfer start address = (y coordinate of start point) × VRAM 1 line size + (x coordinate of start point−1) (1)
Here, the storage capacity of the memory area corresponding to the pixel area for three lines from the top in the display area shown in FIG. 4 is obtained by “(y coordinate of start point) × VRAM one line size”. The storage capacity corresponding to the number of pixels reduced by 1 from the x-coordinate value, that is, the storage capacity corresponding to the pixels from the left end of the fourth row from the top to the fourth in FIG. 4 is added. Therefore, the storage capacity of the pixels from the pixel including the origin (0, 0) to the fourth pixel in the x-axis direction of the fourth row is obtained by the above formula (1).

  From the relationship between each address in the memory area 80 and the storage capacity of the memory area corresponding to each address, the transfer start address 41 can be calculated based on the result of the above equation (1).

  In this embodiment, in FIG. 4, the number of rows is defined as the first row, the second row, the third row,... From the origin (0, 0) in the y-axis direction. . Therefore, for example, the area corresponding to A is the pixel area of the first row in the display area.

  Further, in this embodiment, in the pixel region in which the rectangular image 70 is drawn, the arrangement of pixels on the x-axis side (side closer to the origin) is the first line, and from the origin (0, 0) toward the y-axis direction, The number of rows of the pixels forming the rectangular image 70 is defined as the second row, the third row,.

  Further, the parameter determining unit 23 obtains the image one-line size 42 by calculation shown in the following mathematical formula (2).

Line size of image = (x coordinate of end point)-(x coordinate of start point) (2)
By calculating Equation (2) above, it is possible to calculate the storage capacity of the memory area range corresponding to the pixels of one row (B range) in the x-axis direction of the rectangular image 70. That is, the number of pixels for one row in the rectangular image 70 is obtained by calculating the mathematical formula (2). Further, since the storage capacity of one pixel is determined, the storage capacity for one row in the rectangular image 70 is obtained from the number of pixels calculated by the above mathematical formula (2).

  Further, the parameter determination unit 23 obtains the loop count 44 by the calculation shown in the following mathematical formula (3).

Loop count = (y coordinate of end point) − (y coordinate of start point) (3)
By calculating Equation (3), the number of pixels in the y-axis direction of the rectangular image 70, that is, the number of pixels corresponding to the E range in FIG. 4 can be obtained. The number of pixels in the y-axis direction corresponds to the number of rows of pixels for drawing the rectangular image 70.

  Therefore, in order to draw the rectangular image 70 by the mathematical formula (3), it can be understood how many times the image data corresponding to the arrangement of the pixels of one row of the rectangular image 70 should be repeated.

  Next, the parameter determination unit 23 calculates the offset amount 43 based on the image one-line size 42 calculated by the mathematical formula (2) and the VRAM one-line size 34 (S13). More specifically, the parameter determination unit 23 calculates the offset amount by the following mathematical formula (4).

Offset amount = VRAM 1 line size−Image 1 line size (4)
In other words, the storage capacity in the memory area corresponding to the pixels in the range of C + D in FIG. 4 can be calculated by performing the calculation according to the mathematical formula (4).

  The parameter determination unit 23 causes the start parameter storage unit 25 to store the parameter values of the transfer start address 41, the image one-line size 42, the offset amount 43, and the loop count 44 calculated in steps S12 and S13 as described above (S14). ). Then, the parameter determination unit 23 notifies the memory transfer start unit 22 of an image data transfer instruction.

  In response to the image data transfer instruction notified from the parameter determination unit 23, the memory transfer start unit 22 instructs the DMA transfer unit 21 to start DMA transfer of image data (S15).

  When receiving an instruction to start image data transfer from the memory transfer start unit 22, the DMA transfer unit 21 initializes the transfer source address 45 and the current loop count 46 stored in the transfer information storage unit 26 (S16). . That is, the DMA transfer unit 21 sets the values corresponding to the transfer source address 45 and the current loop count 46 to 0.

  Then, the DMA transfer unit 21 sets the transfer start address 41 stored in the start parameter storage unit 25 as the transfer source address 45 (S17). Next, the DMA transfer unit 21 compares the current loop count 46 with the loop count 44 stored in the start parameter storage unit 25 to determine whether the former is greater than or equal to the latter (S18). Here, since the current loop count 46 is the initial setting “0”, “No” is set in step S18.

  If “No” in step S18, the DMA transfer unit 21 acquires image data for one image line size 42 from the VRAM 6 and transfers it to the LCD display buffer 4 (S19). That is, the DMA transfer unit 21 acquires from the VRAM 6 the image data stored in the memory area from the transfer source address 45 to the address corresponding to the storage capacity for one image line size 42.

  Then, the DMA transfer unit 21 increases the current transfer source address 45 by an address corresponding to the storage capacity of one image line size 42. Therefore, at this time, the transfer source address 45 is an address corresponding to the last pixel in the pixel area of the first row of the rectangular image 70. Further, the DMA transfer unit 21 refers to the offset amount 43 stored in the start parameter storage unit 25, and increases the current transfer source address 45 by an address corresponding to the offset amount 43 minutes (S20).

  As described above, when the transfer of the image data for one line of the rectangular image 70 from the VRAM 6 to the LCD display buffer 4 is completed, the DMA transfer unit 21 increases the current loop count 46 by 1 (S21).

  The DMA transfer unit 21 repeats the processing from steps S18 to S21 until the current loop count 46 becomes equal to or greater than the loop count 44 stored in the start parameter storage unit 25. That is, the current loop count 46 being equal to or greater than the loop count 44 means that the image data corresponding to all the pixels of the rectangular image 70 has been transferred from the VRAM 6 to the LCD display buffer 4.

  Thus, when the current loop count 46 becomes equal to or greater than the loop count 44 stored in the start parameter storage section 25 (“YES” in S18), the display control section 3 is stored in the LCD display buffer 4. Control is performed so that the displayed image data is displayed on the LCD display unit 2 (S22).

  The above is the flow of the image data transfer process in the transfer control device 5 according to the present embodiment. As described above, the transfer control device 5 according to the present embodiment calculates information indicating the storage pattern of the image data of the rectangular image 70 in the VRAM 6 as the start parameter 50. Then, based on the calculated start parameter 50, image data for each row of pixels arranged in the x-axis direction for drawing the rectangular image 70 can be transferred from the VRAM 6 to the LCD display buffer 4.

  Further, in the transfer control device 5, the DMA transfer unit 21 does not need to inquire the CPU 10 about the start address of the memory area in which the pixel arrangement is stored each time the image data for each row of pixels is transferred. . For this reason, the transfer control device 5 according to the present embodiment can reduce the load on the CPU 10 and more efficiently transfer image data.

  The calculation performed by the parameter determination unit 23 to calculate the start parameter 50 is a simple four arithmetic operation. In addition, the information amount handled by the parameter determination unit 23 is very small. Therefore, the parameter determination unit 23 can obtain the start parameter with a small amount of calculation. That is, the transfer control device 5 can realize efficient image data transfer with a small amount of calculation.

  Further, as described above, in the transfer control device 5 according to the present embodiment, the DMA transfer unit 21 that executes DMA transfer, the memory start unit 22 that instructs the DMA transfer unit 21 to transfer image data, and the DMA This is a simple configuration including a parameter determination unit 23 for calculating a start parameter 50 for realizing the efficiency of transfer of image data by the transfer unit 21. That is, it can be said that the transfer control device 5 according to the present embodiment can efficiently transfer the image data of the rectangular image 70 with a simple device configuration.

  Further, in the LCD display system 1 according to the present embodiment, the transfer control device 5 receives from the VRAM 6 the image data of the rectangular image 70 defined by these coordinates based on arbitrarily designated start point coordinates 31 and end point coordinates 32. The data can be transferred to the readout display device 13. That is, the LCD display system 1 according to the present embodiment can draw a rectangular image 70 having an arbitrary size.

  In the above description, the case where the pixel is specified by the coordinate value of the upper left point of the pixel in the display area has been described. However, the present invention is not limited to this. In other words, each pixel may be specified by the coordinates of the upper right point of the pixel, or each pixel may be specified by the coordinates of the lower right or lower left point.

  It should be noted that although the expressions on the mathematical expressions (1) to (3) described above differ depending on which coordinate point identifies one pixel, the relationship between the input value and the output value does not change. That is, the relationship of calculating the transfer start address, the image one line size, and the loop count, which are output values, based on the start point coordinates 31, the end point coordinates 32, and the VRAM one line size 34 is the same.

  In addition, the LED display system 1 according to the present embodiment is a system including the display device 13, the transfer control device 5, and the VRAM 6. However, the plurality of devices are configured by a single casing, and one LED display. An apparatus may be configured.

  Note that the memory transfer start unit 22 and the parameter determination unit 23 of the transfer control device 5 of the above embodiment, or each processing step executed by these units is performed by a calculation means such as the CPU 10 such as a ROM (Read Only Memory) 11 or the like. This can be realized by executing a program stored in the storage means and controlling input means such as a keyboard, output means such as a display, or communication means such as an interface circuit.

  Therefore, the computer having these means can be realized by the memory transfer start unit 22 and the parameter determination unit 23 of the transfer control device of the present embodiment just by reading the recording medium storing the program and executing the program. Various functions and various processes can be performed.

  Further, the DMA transfer unit 21 of the transfer control device 5 of the above embodiment is a functional block that the DMAC 9 reads and realizes the program, but may be a functional block that the CPU 10 reads and realizes the program from the ROM 11 or the like. That is, in this case, image data is transferred not by the DMAC 9 but by the CPU 10.

  As described above, even when the image data is transferred by the CPU 10, the transfer control device 5 according to the present embodiment needs to confirm the address where the image data to be transferred is stored during the transfer of the image data. Therefore, efficient image data transfer can be realized.

  Further, when the transfer unit 21 is executed by a calculation unit such as the CPU 10, as described above, the CPU 10 executes the program stored in the storage unit such as the ROM 11, and an input unit such as a keyboard, a display, etc. This can be realized by controlling the output means or the communication means such as an interface circuit.

  In addition, by recording the program on a removable recording medium, the various functions and various processes described above can be realized on an arbitrary computer.

  As the recording medium, a memory (not shown) such as a ROM may be used as a program medium for processing by the microcomputer, and a program reader is provided as an external storage device (not shown). It may be a program medium that can be read by inserting a recording medium therein.

  In any case, the stored program is preferably configured to be accessed and executed by the microprocessor. Furthermore, it is preferable that the program is read out, and the read program is downloaded to the program storage area of the microcomputer and the program is executed. It is assumed that the download program is stored in the main device in advance.

  The program medium is a recording medium configured to be separable from the main body, such as a tape system such as a magnetic tape or a cassette tape, a magnetic disk such as a flexible disk or a hard disk, or a disk such as a CD / MO / MD / DVD. Fixed disk system, card system such as IC card (including memory card), or semiconductor memory such as mask ROM, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), flash ROM, etc. In particular, there are recording media that carry programs.

  In addition, if the system configuration is capable of connecting to a communication network including the Internet, the recording medium is preferably a recording medium that fluidly carries the program so as to download the program from the communication network.

  Further, when the program is downloaded from the communication network as described above, it is preferable that the download program is stored in the main device in advance or installed from another recording medium.

  It can also be said that the control method related to the image data transfer process in the transfer control device 5 according to the present embodiment includes the following processing steps.

  That is, a transfer parameter determining step for determining a parameter (start parameter 50) required for transfer from the start point coordinates 31 and end point coordinates 32 of the transfer rectangle in the image data arranged in the transfer source memory area, and the control unit (CPU 10). A transfer start step for transmitting a transfer parameter (start parameter 50) to the DMA transfer unit 21 and instructing the start of memory transfer, and a transfer in which the DMA transfer unit 21 copies image information from the transfer source memory to the transfer destination memory This is a memory transfer system consisting of steps. In this memory transfer method, in the transfer parameter determining step, the transfer start address 41, the number of one-line size of the image 42, the offset amount 43 to the next row, and the loop count 44 are determined, and the transfer start step is performed once. The rectangular transfer is performed only once, and in the transfer step, the memory area corresponding to the target rectangular area is autonomously transferred collectively from the given parameters.

  In addition, it can be said that the transfer control device 5 according to the present embodiment has the following characteristics. In other words, the transfer control device 5 is a control unit that controls the DMAC 9 as the DMA transfer unit 21, the VRAM 6 as the transfer source memory, an arbitrary memory area as the transfer destination memory, and the calculation of parameters required for transfer and the start of transfer. CPU10. The transfer control device 5 is characterized by using the above-described memory transfer method.

  The transfer destination memory may be the LCD display buffer 4.

  Moreover, the LED display system 1 according to the present embodiment can be a system that displays an image on a screen display unit using the transfer control device 5 having the above-described configuration.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible in the range shown to the claim. That is, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

  The transfer control device according to the present embodiment can efficiently transfer image data of a rectangular image. For this reason, smooth image drawing can be realized by efficiently transferring image data of a rectangular image in which text or an illustration is drawn from a VRAM or the like to a display device and displaying it on the display device.

1, showing an embodiment of the present invention, is a block diagram illustrating an example of a main configuration of a transfer control device. FIG. 1, showing an embodiment of the present invention, is a block diagram showing a schematic configuration of an LCD display system. FIG. 1, showing an embodiment of the present invention, is a diagram showing a main configuration of an LCD display system. FIG. FIG. 4 is a diagram illustrating a correspondence relationship between a display area of an LCD display unit and a memory area of a VRAM according to an embodiment of the present invention. 5 is a flowchart illustrating a DMA transfer process according to an embodiment of the present invention. It is a figure which shows a prior art and shows schematic structure of the computer system using DMAC.

Explanation of symbols

1 LCD display system (image transfer system)
2 LCD display 4 LCD display buffer (buffer)
5 Transfer control device (transfer device)
6 VRAN (storage device)
9 DMAC
10 CPU
13 Display device 21 DMA transfer section (transfer means)
22 Memory transfer start unit (instruction means)
23 Parameter determination unit (calculation means)
31 Start point coordinates 32 End point coordinates 33 Memory start address 34 VRAM 1 line size (display range information)
41 Transfer start address 42 Line size of image (drawing range information)
43 Offset amount (interval range information)
44 Loop count (pixel column number information)
50 Start parameter (storage pattern information)
70 Rectangular image (rectangular image area)
80 Memory area (storage area)

Claims (8)

A transfer device that transfers rectangular image information from a storage device that holds rectangular image information for displaying a rectangular image region to the display device,
When the horizontal direction in the display area of the display device is the x coordinate and the vertical direction is the y coordinate,
A pixel in the display area specified by the x coordinate and the y coordinate is associated with an address in the storage area of the storage device that stores rectangular image information to be displayed in the pixel,
The addresses corresponding to pixels adjacent in the horizontal direction are consecutive in the order of reading,
A storage pattern indicating a storage pattern of rectangular image information in the storage device based on start point coordinates and end point coordinates that are diagonal end points of the rectangular image region and display range information corresponding to the number of pixels in the horizontal direction in the entire display region A calculation means for calculating information;
An instruction means for instructing the transfer means to transfer the rectangular image information based on the storage pattern information calculated by the calculation means;
A transfer device comprising: transfer means for transferring the rectangular image information to a display device based on the storage pattern information in response to an instruction from the instruction means. The above storage pattern information is
An address read first in the storage area storing the rectangular image information;
Drawing range information corresponding to the number of pixels in the horizontal direction in the drawn rectangular image area;
Pixel column number information indicating the number of pixels in the vertical direction included in the rectangular image region;
2. The transfer apparatus according to claim 1, further comprising interval range information corresponding to the number of pixels between a pixel column that is an arrangement of pixels in the horizontal direction in the rectangular image region and a next pixel column. The display device includes a buffer for temporarily storing rectangular image information to be displayed,
3. The transfer device according to claim 1, wherein the transfer unit transfers rectangular image information stored in the storage device to the buffer.   4. The transfer unit according to claim 1, wherein the transfer means acquires the right to use the bus from a CPU that controls various processes of the transfer device and transfers the rectangular image information to the display device without going through the CPU. The transfer device according to any one of the above. A control method of a transfer device that transfers rectangular image information to a display device from a storage device that holds rectangular image information for displaying a rectangular image region,
When the horizontal direction in the display area of the display device is the x coordinate and the vertical direction is the y coordinate,
A pixel in the display area specified by the x coordinate and the y coordinate is associated with an address in the storage area of the storage device that stores rectangular image information to be displayed in the pixel,
The addresses corresponding to pixels adjacent in the horizontal direction are consecutive in the order of reading,
A storage pattern indicating a storage pattern of rectangular image information in the storage device based on start point coordinates and end point coordinates that are diagonal end points of the rectangular image region and display range information corresponding to the number of pixels in the horizontal direction in the entire display region Calculating information;
Instructing to transfer rectangular image information based on the calculated storage pattern information;
And a step of transferring the rectangular image information to a display device based on the storage pattern information in response to an instruction to transfer the rectangular image information. The transfer device according to any one of claims 1 to 4,
A storage device for holding rectangular image information for displaying a rectangular image region;
An image transfer system comprising: a display device that displays the rectangular image information.   5. A control program for operating the transfer apparatus according to claim 1, wherein the transfer apparatus control program causes a computer to function as each of the means.   A computer-readable recording medium on which the control program for the transfer apparatus according to claim 7 is recorded.

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