JP2011015030A - Data transmitter, data receiver, and data transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data transmission system capable of saving power and lowering EMI by reducing the number of data transitions of a signal line in data transmission between devices such as a memory I/F and a liquid crystal I/F.SOLUTION: In the data transmission system, feature points are extracted in the data transmitter and the data receiver respectively when graphics data are updated, and when the following graphics data are not updated, the data transmitter encodes and transmits not difference data but the index of the feature point for the feature point extracted when update is performed. Also in the data receiver, not the difference data but the index of the feature point is decoded at the feature point extracted when the update is performed, similarly.

Description

  The present invention relates to a data transmission device, a data reception device, and a system for transmitting encoded data.

  In recent years, the amount of data handled in mobile devices such as mobile phones has become enormous, and as with large devices, data transfer between devices such as memory I / F and liquid crystal I / F can be reduced, and EMI ( Electro-Magnetic Interference (Electromagnetic Interference) is a challenge.

  Therefore, conventionally, a method for reducing power consumption and reducing EMI noise by reducing the number of signal line data transitions (hereinafter also referred to as “bit inversion number”) in a bus such as a memory I / F or a liquid crystal I / F. (For example, refer to Patent Document 1).

  Patent Document 1 discloses a technique for reducing the number of data transitions in a serial bus. In this patent document 1, the appearance probability of difference data with a neighboring pixel is biased (concentrated in the vicinity of 0) in a natural image or the like, and a numerical value with high appearance probability of difference data is used. On the other hand, a code with a small number of bit inversions is assigned (for example, 0 is 00000000, +1 is 00000001, -1 is 11111110, etc.), and the number of data transitions is reduced.

JP 2006-157443 A

  However, especially in mobile devices and the like, such as TV viewing and video playback, where natural images are mainly displayed on the screen, graphics images such as mobile phone signal strength and menus are superimposed at the same time. There are many cases. In the method of encoding difference data with adjacent pixels as in Patent Document 1 by allocating a code that reduces the number of transitions with respect to a numerical value with a high appearance probability, the number of signal line data transitions in a natural image region Although the effect of reduction is high, it is difficult to find the effect because the difference between adjacent pixels is not distributed in the vicinity of 0 in the graphics image area. Therefore, there is a demand for a technique that can be used in combination with a technique that can effectively reduce the number of data transitions for a natural image as in Patent Document 1, and that can reduce the number of data transitions even in the area of a graphics image.

  The data transmission system of the present invention receives transmission data for each predetermined unit and transmits encoded data using an n-bit (n is a natural number of 1 or more) signal line, and the encoded data A data transmission system comprising a data receiving device for receiving data, wherein the data transmitting device takes a difference between n-bit unit data in the transmission data and the previous n-bit unit data. A transmission-side feature point in which a transmission-side arithmetic unit that generates difference data, a transmission-side feature point extraction unit that extracts a feature point at which the difference data is greater than a predetermined threshold, and the feature point data and an index are associated with each other The transmission-side feature point information holding unit that holds information and the transmission data in units after the transmission data from which new feature points have been extracted by the transmission-side feature point extraction unit The index corresponding to the data of the feature point is selected at a point, the transmission side selection unit that selects the difference data other than the feature point, and the index or the difference data selected by the transmission side selection unit is encoded And an encoding unit that generates the encoded data of n bits, and the data receiving device decodes the received encoded data of n bits to generate decoded data in units of n bits A receiving-side feature point extracting unit that extracts a feature point at which the decoded data is larger than a predetermined threshold, and a receiving-side feature point information in which the feature point data and the index are associated with each other. Feature point information holding unit, receiving side calculation unit that generates n-bit unit calculation data, and units after encoded data from which new feature points have been extracted by the reception side feature point extraction unit For encoded data, at the feature point, the feature point data corresponding to the index indicated by the decoded data of the feature point is selected from the reception-side feature point information, and the operation data other than the feature point is selected. A receiving side selecting unit that selects and outputs the selected data as n-bit unit selection data, wherein the receiving side arithmetic unit includes the n-bit unit decoded data generated by the decoding unit and the preceding data And the n-bit unit selection data output from the receiving side selection unit is added to generate operation data in the n-bit unit, and the selection data is used as reception data.

  In the data transmission system of the present invention, each of the data transmission device and the data reception device extracts a feature point having a low correlation between adjacent data, stores the feature point data in association with the index, and the feature point is For the transmission data after extraction, since the data encoded with the index is transmitted, the technology of reducing the number of data transitions in the signal line by utilizing the high correlation of the adjacent data, When there is a place where the correlation is low, the number of data transitions can be reduced even for data with a low correlation.

The block diagram of the data transmission system in the 1st Embodiment of this invention Coding table according to the first embodiment of the present invention Feature point color table in the first embodiment of the present invention The figure which shows the example of the coding data about the updated frame in the 1st Embodiment of this invention The figure which shows the example of the coding data after the frame following the updated frame in the 1st Embodiment of this invention The block diagram of the data transmission system in the 2nd Embodiment of this invention The figure which shows the example of the encoding of data and the calculation in the 2nd Embodiment of this invention The block diagram of the data transmission system in the 3rd Embodiment of this invention The block diagram of the data transmission system in the 4th Embodiment of this invention

  Hereinafter, a data transmission system according to an embodiment of the present invention will be described with reference to the drawings. The data transmission system of the present invention is effective for both a system that transmits data using a serial bus and a system that transmits data using a parallel bus. In the present invention, the difference appearance probability between adjacent data is biased (concentrated in the vicinity of 0), and the number of transitions in the signal line is small with a numerical value having a high difference data appearance probability. Therefore, the present invention is effectively applied to a system for transmitting data by performing encoding that allocates such encoded data. Such encoding is realized, for example, by assigning encoded data of 00000000, 00000001, and 11111110 to differential data 0, +1, and −1, respectively, when data is transmitted through a serial bus. . Hereinafter, a case where data is transmitted through a parallel bus will be described as an example.

(First embodiment)
FIG. 1 is a block diagram of a data transmission system according to the first embodiment of the present invention. The data transmission system 10 includes a data transmission device 100 that transmits data and a data reception device 110 that receives data. In the present embodiment, the data transmission device 100 is a system LSI, the data reception device 110 is a display device, and a display data transmission system is configured by these. The transmission data is RGB format image data.

  Further, in the data transmission system 10 according to the present embodiment, 8-bit data (24 bits in total) is parallelized for each of RGB through a 24-bit signal line between the data transmitting apparatus 100 and the data receiving apparatus 110. Is transmitted. The data transmission device 100 and the data reception device 110 store a data transmission program and a data reception program, respectively. The data transmitting apparatus 100 and the data receiving apparatus 110 execute the operations described below according to these programs.

  An image control device 500 is connected to the data transmission device 100 and the data reception device 110. The image control apparatus 500 outputs an update notification when graphics data included in image data to be transmitted is updated.

  The data transmission apparatus 100 includes a delay unit 101, a calculation unit 102, a feature point extraction unit 103, a feature point information holding unit 104, a selection unit 105, and an encoding unit 106. Image data that is transmission data is input to the data transmission apparatus 100 in the pixel arrangement order. When one frame of image data is input, the next frame of image data is input.

  The delay unit 101 delays the input transmission data and outputs the delay data to the calculation unit 102. The calculation unit 102 receives transmission data as well as delay data output from the delay unit 101. The calculation unit 102 generates difference data by taking the difference between the data of a certain pixel directly input and the delay data (previous pixel data) output from the delay unit 101, and generates the difference data as the selection unit 105 and Output to the feature point extraction unit 103.

  When the update notification is received from the image control apparatus 500, the feature point extraction unit 103 extracts, from the difference data of the transmission data related to the update notification, a feature point whose difference value of the difference data is greater than or equal to a preset threshold value. To do.

  The feature point information holding unit 104 holds the feature point position (for example, X coordinate = 2, Y coordinate = 1, etc.) extracted by the feature point extraction unit 103 and feature point information. In the feature point information, the correspondence between the feature point index and the color information (pixel value) is defined in the form of a feature point color table.

  When the feature point extraction unit 103 receives the update notification from the image control device 500 and extracts the feature point, the feature point information holding unit 104 holds the feature point information before receiving the update notification. The old feature point information is overwritten with new feature point information in ascending order of the absolute value of the index. As described above, the feature point information is overwritten and updated every time the graphics data is updated.

  FIG. 3 is a feature point color table held in the feature point information holding unit 104. In the feature point color table, pixel color information (pixel values) extracted by the feature point extraction unit 103 is associated with an index.

  In addition, if the information held in the feature point information holding unit 104 increases, the cost of the system increases. For this reason, the feature point information holding unit 104 may limit an image area in which feature points are extracted and held. In mobile devices such as mobile phones, even when natural images such as TV viewing and video playback are mainly displayed on the screen, graphics images such as mobile phone signal strength and menus are simultaneously superimposed at specific locations. There are many cases.

  Therefore, the feature points may be extracted by the feature point extraction unit 103 only in places where such graphics images are superimposed. In addition, an upper limit is set on the number of pieces of information held in the feature point information holding unit 104 (for example, the number of feature points and the number of colors that can be registered in the feature point color table), and the one with a large difference value of the difference data is given priority May be extracted as feature points and the feature point information may be retained.

  The selection unit 105 selects either the difference data generated by the calculation unit 102 or the feature point index read from the feature point information holding unit 104 and outputs the selected data to the encoding unit 106 as selection data.

  The encoding unit 106 receives the difference data or the feature point index output from the selection unit 105, encodes it into 8-bit data, and outputs it as encoded data. These operations are performed on 8-bit data of each RGB element. The 8-bit encoded data of each element output from the encoding unit 106 is transmitted to the data receiving apparatus 110 through a signal line of 8 bits (24 bits when all the RGB elements are combined).

  FIG. 2 is an encoding table used when encoding is performed by the encoding unit 106. In the encoding table shown in FIG. 2, 00000000 is associated with 0. The encoded data is associated with the value 00000000 corresponding to 0 so that the bit inversion on each signal line is smaller as the absolute value is smaller.

  For example, taking 1 and 20 as an example, the last bit to be inverted between 00000001 associated with 1 having a smaller absolute value and 00000000 associated with 0 is the number of bit inversions of 1. is there. On the other hand, the number of bits inverted between 00001011 associated with 20 and 00000000 associated with 0 is the first digit, the second digit, and the fourth digit, and the bit inversion number is 3.

  In this way, the number of bit inversions from 00000000 associated with 0 is smaller for 1 having a smaller absolute value than for 20 having a larger absolute value.

  A natural image has a high correlation between neighboring pixels, and a difference value between adjacent pixels has a Laplace distribution. That is, the difference value with the adjacent pixel has a very high appearance probability of 0, and the appearance probability decreases rapidly as the absolute value of the difference value increases.

  When transmitting transmission data having such characteristics through a parallel bus, the number of bit inversions in each signal line of the parallel bus can be reduced by using an encoding table as shown in FIG. 2, thereby saving power. And low EMI can be achieved.

  In parallel transmission of image data such as a natural image, the principle that the number of bit inversions can be reduced by using the encoding table of FIG. 2 is as follows.

  When continuous data having Laplace distribution characteristics, such as natural image data, is transmitted, the difference probability at the present time (time t) has a high appearance probability of a value having a small absolute value centered on 0. Also at the previous time (t−1), the appearance probability of difference data having a small absolute value centering on 0 is high.

  Therefore, at time t and time (t−1), the probability of transition from a smaller absolute value to a smaller absolute value is higher. Therefore, when a transition is made from a smaller absolute value to a smaller absolute value, encoding is performed so that the number of bit inversions on each parallel bus is smaller, so that data transmission can be performed on each bus. , The number of times the bit is inverted can be reduced.

  In the encoding table of FIG. 2, encoded data in which the bit inversion number from 0 is 1 is allocated to −4 to −1 and +1 to +4, which are differential data with smaller absolute values. Here, the encoded data whose bit inversion number is 1 is encoded data including only 1 in 8 bits when the encoded data corresponding to the difference data 0 is 00000000.

  Also, encoded data with a bit inversion number of 2 is allocated to −18 to −5 and +5 to +18, which are differential data with smaller absolute values except for −4 to +4. The encoded data whose bit inversion number is 2 is encoded data including two 1's in 8 bits when the encoded data corresponding to the difference data 0 is 00000000.

  Here, where 1 is included in 8 bits is determined such that the smaller the absolute value of the difference data, the smaller the number of transitions with the encoded data corresponding to the difference data + 1.

  Specifically, in the difference data +5 to +11, the least significant bit is set to 1 so that the bit inversion number from the difference data +1 is 1. In the difference data -5 to -11, the most significant bit is set to 1 so that the bit inversion number from the difference data -1 is 1.

  Further, where one of the 7 bits from +5 to +11 is included corresponds to difference data +2 (difference data having the next smallest absolute value after difference data +1) as the absolute value of the difference data is smaller. The determination is made so that the number of transitions with the encoded data is small.

  Specifically, in the difference data +5 to +11, the second bit from the least significant bit is set to 1 so that the number of bit transitions from the difference data +2 is 1 in the difference data +5.

  In the same manner, encoded data whose bit inversion number from 0 is 3, 4,. As described above, the encoding table has a rule that the difference data having a smaller absolute value is associated with the encoded data having a smaller bit inversion number with the encoded data associated with 0 of the difference data. However, even if this rule is not applied to all differential data, the above effect can be obtained.

  For example, even if some of the difference data has a relatively large absolute value and the above rule is not applied, the larger the absolute value of the difference data, the smaller the probability of occurrence. The influence on the reduction effect of the number of bit inversions is reduced.

  Next, the selection operation by the selection unit 105 will be described. Upon receiving the update notification from the image control apparatus 500, the selection unit 105 receives the update data of the next frame of the transmission data related to the update notification, and the coordinates (feature points) held in the feature point information holding unit 104 are as follows. With reference to the feature point color table in FIG. 3, an index corresponding to the color information (pixel value) of the feature point is selected and output to the encoding unit 106.

  The selection unit 105 selects the index held in the feature point information holding unit 104 in the same manner until a new update notification is received from the image control apparatus 500. When a new update notification is received from the image control apparatus 500, for the frame related to the update notification, the difference data generated by the calculation unit 102 including the feature points is selected and output to the encoding unit 106.

  As described above, the selection unit 105 selects the difference data including the feature points for the frame in which the graphics data is updated. Further, the selection unit 105 selects the index held in the feature point information holding unit 104 for the feature point from the frame next to the frame in which the graphics is updated until the next time the graphics data is updated. Then, difference data is selected for points other than the feature points.

  As shown in FIG. 3, in the feature point color table, a value having a small absolute value is adopted for the index. Therefore, the number of data transitions of each signal line can be reduced according to the above principle by selecting an index instead of difference data for a feature point where the difference between adjacent pixels is large. The absolute value of the index is made smaller than the threshold value used in the feature point extraction unit 103.

  The data receiving apparatus 110 includes a decoding unit 116, a feature point extraction unit 113, a feature point information holding unit 114, a selection unit 115, a calculation unit 112, and a delay unit 111. The decoding unit 116 receives the encoded data transmitted from the data transmitting apparatus 100 and decodes it to generate decoded data.

  At the time of this decoding, the decoding unit 116 uses the same table as the table used for encoding in the encoding unit 106 of the data transmitting apparatus 100, that is, the encoding table shown in FIG. Therefore, the decoded data becomes the difference data selected by the selection unit 105 of the data transmission apparatus 100 or the index of the feature points.

  Similar to the feature point extraction unit 103 of the data transmission device 100, the feature point extraction unit 113 extracts a feature point from the decoded data upon receiving an update notification from the image control device 500. At this time, the feature point extraction unit 113 uses the same threshold as the threshold used by the feature point extraction unit 103. That is, the feature point extraction unit 113 extracts feature points under the same conditions as the feature point extraction unit 103.

  Further, the feature point information holding unit 114 holds the position of feature points and the feature point information in the same manner as the feature point information holding unit 104 of the data transmission apparatus 100. The method of holding the feature point information (including the creation of the feature point color table) is the same as that of the feature point information holding unit 104 of the data transmission apparatus 100. As a result, the same information is held in the feature point information holding unit 104 of the data transmitting apparatus 100 and the feature point information holding unit 114 of the data receiving apparatus 110.

  The calculation unit 112 calculates and outputs calculation data. The delay unit 111 delays the output selection data selected by the selection unit 115 and outputs the delayed selection data to the calculation unit 112. The calculation unit 112 adds the decoded data obtained by the decoding unit 113 and the previous pixel selection data output from the delay unit 111, and outputs the result as calculation data. This calculation data is obtained by restoring the pixel value of the original transmission data.

  In the same manner as the selection unit 105 of the data transmission device 100, the selection unit 115 receives an update notification from the image control device 500, and outputs a frame in which graphics data is updated, including the feature points, from the calculation unit 112. Selected operation data is selected. Further, the selection unit 115 refers to the color information table of the feature point information holding unit 114 for the feature points from the frame next to the frame in which the graphics data is updated, and the decoded data of the feature points is stored. Color information corresponding to the indicated index is selected from the feature point information holding unit 114. Here, the selection unit 115 selects the calculation data output from the calculation unit 112 except for the feature points.

  FIG. 4 is a diagram illustrating encoded data for a frame in which graphics data is updated. FIG. 5 is a diagram illustrating encoded data subsequent to the frame in which the graphics data is updated.

  4 and 5 show examples of data of a line with Y coordinate = 1 in a certain frame. In this example, the transmission data (pixel values) are 20, 21, 109, 109, 110, 110,... In order from the X coordinate = 0. In this case, the output of the delay unit 101 (here, the initial state is set to 0) is 0, 20, 21, 109, 109, 110,... , 88, 0, 1, 0,... Are generated and output to the feature point extraction unit 103 and the selection unit 105.

  In this example, the threshold used to extract feature points is 20. The feature point extraction unit 103 extracts a point of X coordinate = 2 where the difference data is greater than or equal to the threshold 20 as a feature point. Note that the difference data of X coordinate = 0, which is the first pixel, is not subject to feature point extraction.

  The feature point information holding unit 104 uses the position of the X coordinate = 2 and the Y coordinate = 1 as a feature point, holds the position information, and creates a feature point color table for the feature point. Specifically, for example, as shown in the first row of the table of FIG. 3, an index 0 is assigned to the color information (pixel value) 109 at this position to create a feature point color table.

  In this manner, the feature point is extracted, and the feature point color table is generated by holding the position information of the feature point. For the frame, the selection unit 105, as shown in FIG. As the data, difference data 88 is selected and output to the encoding unit 106. That is, this frame is a frame in which graphics data is updated.

  In the encoding unit 106, for the frame in which the graphics data has been updated, the difference data 20, 1, 88, 0, 1, 0 is respectively changed from 20 → 00001011, 1 → according to the encoding table shown in FIG. The data is encoded as 00000001, 88 → 10010111, 0 → 00000000, 1 → 00000001, 0 → 00000000,..., And is transmitted to the data receiving apparatus 110. In this case, the bit inversion numbers from X coordinate = 1 to 5 are 2, 4, 5, 1, 1.

  As shown in FIG. 5, in the subsequent frames after the updated frame, for the feature points of X coordinate = 2 and Y coordinate = 1, the selection unit 105 is created in the frame in which the graphics data is updated. With reference to the feature point color table, the index 0 corresponding to the pixel value 109 of the feature point is selected and output to the encoding unit 106.

  When this is encoded by the encoding unit 106, encoded data of 00000000 is generated. Then, the bit inversion number from X coordinate = 1 to 5 is 2, 1, 0, 1, 1, and the bit inversion number (2, 4, 5, 1) of the frame in which the graphics data shown in FIG. 4 is updated. Compared with 1), the bit inversion number of the frame in which the subsequent graphics data is not updated is reduced.

  In a natural image or the like, the difference data of color difference (for example, RG) tends to have a higher appearance probability of a value near 0 than the difference data of G. For this reason, the number of bit inversions can be reduced more in the transmission data in which the two elements are color differences (RG, RB) from R rather than the transmission data of each RGB data.

  According to the data transmission system 10 in the present embodiment, each of the data transmitting apparatus 100 and the data receiving apparatus 110 has a pixel having a low correlation between pixel values or color differences, such as a boundary between graphics data and a natural image, as a feature point. Extracting and holding the color information (pixel value and color difference) of the feature point in association with the index, and for the frame after the feature point is extracted, the encoded data encoding the index is transmitted. In the technology that reduces the number of data transitions in signal lines by utilizing the characteristics of natural images that have high correlation between adjacent color information, the correlation between adjacent color information, such as the boundary between graphics data and natural images, is partially When there is a low place, the number of data transitions in each signal line can be reduced even for pixels with low correlation.

  Further, according to the present embodiment, since the graphics data is notified by the image control device 500, the feature point extraction unit 103 and the feature point extraction unit 113 have updated graphics. Only when the feature points need to be extracted, the data transmission device 100 and the data reception device 110 can reduce the processing load. In addition, the selection unit 105 and the selection unit 115 do not need to determine whether the graphics data has been updated from the difference data or the like, and the processing load can be reduced.

(Second Embodiment)
FIG. 6 is a block diagram of a data transmission system according to the second embodiment of the present invention. The data transmission system 20 includes a data transmission device 200 that transmits data and a data reception device 210 that receives data.

  In the present embodiment, as in the first embodiment, the data transmission device 200 is a system LSI, the data reception device 210 is a display device, and the data transmission system 20 is a display data transmission system constituted by these. The transmission data is image data in RGB format.

  Further, in the data transmission system 20 in the present embodiment, RGB data is transmitted between the data transmission apparatus 200 and the data reception apparatus 210 through a 24-bit signal line, as in the data transmission system 10 in the first embodiment. 8 bits (24 bits in total) of data is transmitted in parallel. Further, as in the first embodiment, an image control device 500 is connected to the data transmission device 200 and the data reception device 210.

  The data transmission apparatus 200 includes a first delay unit 201, a first calculation unit 202, a feature point extraction unit 203, a feature point information holding unit 204, a selection unit 205, an encoding unit 206, and a second The calculation unit 207 and the second delay unit 208 are included. The data reception apparatus 210 includes a second calculation unit 217, a second delay unit 215, a decoding unit 216, a feature point extraction unit 213, a feature point information holding unit 214, a first delay unit 211, , A first calculation unit 212 and a selection unit 215.

  In the data transmission system 20, a second arithmetic unit 207 and a second delay unit 208 are added to the output stage of the data transmitting apparatus 200 in addition to the first embodiment, and the input stage of the data receiving apparatus 210 is added. In addition to the configuration in the first embodiment, a second arithmetic unit 217 and a second delay unit 215 are added. With this configuration, the data transmission system 20 can further reduce the number of bit inversions.

  In the data transmission device 200, the operations of the first delay unit 201, the first calculation unit 202, the feature point extraction unit 203, the feature point protection information holding unit 204, the selection unit 205, and the encoding unit 206 are the first This is the same as the delay unit 101, the calculation unit 102, the feature point extraction unit 103, the feature point retention information holding unit 104, the selection unit 105, and the encoding unit 106 in the embodiment.

  The second calculation unit 207 generates and transmits encoded calculation data. The second delay unit 208 delays the encoded calculation data generated by the second calculation unit 207 and outputs it to the second calculation unit 207. The second calculation unit 207 obtains an exclusive OR of the encoded data obtained by the encoding unit 206 and the previous encoded calculation data output from the second delay unit 208, and the encoded calculation data Output as.

  The second delay unit 208 outputs 00000000 as an initial value. The encoded calculation data output from the second calculation unit 207 is sequentially transmitted to the data reception device 210 through a signal line of 8 bits (24 bits when all the elements of RGB are combined).

  In the data reception device 210, the second delay unit 215 delays the encoded computation data transmitted from the data transmission device 200 and outputs the delayed data to the second computation unit 217. The second calculation unit 217 receives the encoded calculation data from the second calculation unit 207 and also receives the delay data (previous encoded calculation data) output from the second delay unit 215.

  The second arithmetic unit 217 obtains the second arithmetic data by taking the exclusive OR of the encoded arithmetic data input directly and the previous encoded arithmetic data output from the second delay unit 215. And output to the decoding unit 216.

  In the data transmission system 20, the encoded data generated by the data transmission device 200 in the same manner as in the first embodiment is calculated by the second calculation unit 207 to obtain encoded calculation data, The encoded operation data is transmitted, and the data reception device 210 performs operation on the encoded operation data to generate second operation data.

  The second calculation data matches the encoded data generated by the data transmission device 200. That is, the second calculation unit 217 of the data reception device 210 restores the encoded data. The operations of the decoding unit 216, the feature point extraction unit 213, the feature point information holding unit 214, the selection unit 215, the first delay unit 211, and the first calculation unit 212 are the same as those of the decoding unit according to the first embodiment. 116, the feature point extraction unit 113, the feature point information holding unit 114, the selection unit 115, the delay unit 111, and the calculation unit 112.

  FIG. 7 is a diagram illustrating an example of data encoding and calculation in the second embodiment. In the example of FIG. 7, the same data example as shown in FIGS. 4 and 5 is used. With reference to FIG. 7, operations of the second calculation unit 207 and the second delay unit 208 in the data transmission apparatus 200 will be described.

  When the second calculation unit 207 receives the encoded data 00010011 that is the first output of the encoding unit 206, the second arithmetic unit 207 obtains an exclusive OR with the initial value 00000000 that is the output of the second delay unit 208. 00010011 is output as the encoding calculation data. The second delay unit 208 delays the encoded operation data 00010011 and outputs the delayed operation data to the second operation unit 207 as delay data.

  The second calculation unit 207 obtains an exclusive OR of the second encoded data 00000001 and the previous encoded calculation data 00010011, and outputs the encoded calculation data 00010010.

  Similarly, the second calculation unit 207 calculates the exclusive OR of the encoded data and the previous encoded calculation data, and performs the encoding calculation with 00010010, 00010010, 00010011, 00010011,. Output data. Then, the data transmission device 200 transmits the encoded calculation data to the data reception device 210 in order.

  On the other hand, in the data receiving apparatus 210, the second calculation unit 214 receives the received encoded calculation data 00010011, 00010010, 00010010, 00010010, 00010011, 00010011,... And the output (initial state) of the second delay unit 215. Are the second operation data 00010011, 00000001, 00000000, 00000000, 00000001, 00000000, and the exclusive OR of each bit of 0000100, 00010011, 00010010, 00010010, 00010010, 00010011,. Are output to the decoding unit 216. As apparent from FIG. 7, the second calculation data matches the encoded data obtained by the encoding unit 206 of the data transmission device 200.

  As can be seen by comparing the bit inversion number (2, 1, 0, 1, 1) of the encoded data in FIG. 7 with the bit inversion number (1, 0, 0, 1, 0) of the encoded operation data, In the second embodiment, the number of bit inversions can be further reduced.

(Third embodiment)
FIG. 8 is a block diagram of a data transmission system according to the third embodiment of the present invention. The data transmission system 30 includes a data transmission device 300 that transmits data and a data reception device 310 that receives data.

  In the data transmission system in the first embodiment, the external image control device 500 is connected to the data transmission device 100 and the data reception device 110 to notify the update of graphics data. On the other hand, in the data transmission system 30 in the present embodiment, the fact that the graphics data has been updated indicates that the feature point extraction unit 303 of the data transmission device 300 and the feature point extraction unit 313 of the data reception device 310 The points of detection differ from the first embodiment. Below, only a different part from 1st Embodiment is demonstrated.

  The feature point extraction unit 303 of the data transmission device 300 selects when the feature point is extracted at a position different from the previous frame, and when the feature point is not extracted at the position where the feature point is extracted in the previous frame. An update notification indicating that the graphics data of the frame has been updated is output to the unit 305.

  In this case, as for the newly extracted feature points, the position information and the feature point information are held in the feature point holding unit 304 as in the first embodiment. As with the selection unit 105 in the first embodiment, the selection unit 305 selects the difference data from the calculation unit 302 for the frame that has received the update notification, and in the subsequent frames, The index held in the feature point information holding unit 304 is selected, and difference data is selected for other than the feature points.

  Similarly for the data transmission apparatus 300, the feature point extraction unit 313 does not extract the feature point at the position where the feature point is extracted in the previous frame when the feature point is extracted at a position different from the previous frame. In this case, an update notification indicating that the graphics data of the frame has been updated is output to the selection unit 315.

  In this case, for the newly extracted feature points, the position and feature point information are held in the feature point holding unit 314, as in the first embodiment.

  As with the selection unit 115 in the first embodiment, the selection unit 315 selects the calculation data from the calculation unit 312 for the frame that has received the update notification, and in subsequent frames, the feature points are not selected. The color information held in the feature point information holding unit 304 is selected, and the calculation data is selected except for the feature points.

  According to the present embodiment, it is not necessary to notify the data transmission device and the data reception device of update information from the image control device 500, as compared with the first embodiment, so that the system configuration can be simplified.

(Fourth embodiment)
FIG. 9 is a block diagram of a data transmission system according to the fourth embodiment of the present invention. The data transmission system 40 includes a data transmission device 400 that transmits data and a data reception device 410 that receives data.

  In the data transmission system according to the third embodiment, the data transmission device 300 and the data reception device 310 detect changes in feature points from the difference data and the encoded data, respectively, and grasp that the graphics data has been updated. I was trying to do it.

  In the data transmission apparatus 400 in the present embodiment, the feature point extraction unit 403 detects an update of graphics data and notifies the selection unit 405 of the update in the same manner as the feature point extraction unit 303 in the third embodiment. Is output. On the other hand, the feature point extraction unit 403 of the data transmission device 400 according to the present embodiment is different from the third embodiment in that the update of the graphics data is further notified to the data reception device 410. The other points of the data transmission device 400 are the same as those of the data transmission device 300 in the third embodiment.

  In the first embodiment, the feature point extraction unit 113 and the selection unit 115 of the data reception device 100 receive an update notification from the external image control device 500. On the other hand, the feature point extraction unit 413 and the selection unit 415 of the data reception device 410 according to the present embodiment receive the update notification output from the feature point extraction unit 403 of the data transmission device 400. Other points of the data receiving apparatus 410 are the same as those of the data receiving apparatus 110 in the first embodiment.

  According to the present embodiment, it is not necessary to receive an update notification from an external image control apparatus, and the system configuration is simplified. In addition, since the data receiving device does not need to detect the update of the graphics data from the decoded data, the processing load can be reduced.

(Modification)
In the above embodiment, an 8-bit data bus is used for each element of RGB. However, the number of bits of the data bus is not limited to this, and if each element is 2 bits or more, it is more than that. Or less. For example, each element of RGB is 10 bits, and this may be transmitted using a data bus of 30 bits in total.

  Further, the data to be transmitted is not limited to RGB data, and may be, for example, Y, U, V (luminance and color difference) data. It does not have to be.

  Also, when transmitting RGB data, two elements (for example, G and B) may be transmitted as a color difference from R (RG and RB). Furthermore, in the above-described embodiment, the description has been given focusing on one element (8 bits), taking as an example the case where each element of RGB is regarded as independent and the same processing is performed, but the present invention is not limited to this.

  In the above-described embodiment, the example in which the encoded data corresponding to the difference data 0 is set to 00000000 in the encoding table has been described. However, the encoded data corresponding to the difference data 0 may not necessarily be 00000000. It can be set arbitrarily.

  Further, the data transmission system in the third and fourth embodiments can realize further reduction of the number of data transitions by adding the second arithmetic unit and the second delay unit in the second embodiment. .

  As described above, the data transmission system according to the present invention has the effect of reducing the number of data transitions of the signal line between the data transmission device and the data reception device, thereby realizing power saving and low EMI. However, it is useful as a data transmission system for performing data transmission.

DESCRIPTION OF SYMBOLS 10 Data transmission system 100 Data transmission apparatus 101 Delay part 102 Operation part 103 Feature point extraction part 104 Feature point information holding part 105 Selection part 106 Encoding part 110 Data reception apparatus 111 Delay part 112 Operation part 113 Feature point extraction part 114 Feature point Information holding unit 115 Selection unit 116 Decoding unit 20 Data transmission system 200 Data transmission device 207 Second calculation unit 208 Second delay unit 210 Data reception device 215 Second delay unit 217 Second calculation unit 30 Data transmission system DESCRIPTION OF SYMBOLS 300 Data transmitter 310 Data receiver 40 Data transmission system 400 Data transmitter 410 Data receiver 500 Image control apparatus

Claims (40)

A data transmission apparatus that receives transmission data for each predetermined unit and transmits encoded data using a signal line of n bits (n is a natural number of 1 or more),
An arithmetic unit that generates difference data by taking a difference from n-bit unit data before the data for n-bit unit data in the transmission data;
A feature point extraction unit that extracts feature points where the difference data is greater than a predetermined threshold;
A feature point information holding unit for holding feature point information in which the feature point data and the index are associated;
For transmission data in units after transmission data from which a new feature point has been extracted by the feature point extraction unit, the index corresponding to the data of the feature point is selected at the feature point, and the transmission data other than the feature point A selection unit for selecting difference data;
An encoding unit that encodes the index or the difference data selected by the selection unit to generate the encoded data of n bits;
A data transmission device comprising: A data transmission apparatus that receives transmission data for each predetermined unit and transmits encoded data using a signal line of n (= k × m) bits (k and m are natural numbers of 2 or more),
An arithmetic unit that takes difference between m-bit unit data in the transmission data and the previous m-bit unit data to generate difference data;
A feature point extraction unit that extracts feature points where the difference data is greater than a predetermined threshold;
A feature point information holding unit for holding feature point information in which the feature point data and the index are associated;
A selection unit that selects the index corresponding to the data of the feature point at the feature point and selects the difference data other than the feature point for the transmission data of the unit after the transmission data in which the feature point is updated When,
An encoding unit that encodes the index or the difference data selected by the selection unit to generate the encoded data of m bits;
A data transmission device comprising: A data transmission device that receives transmission data for each predetermined unit and transmits encoded operation data using a signal line of n bits (n is a natural number of 1 or more),
A first calculation unit that generates difference data by taking a difference from n-bit unit data before the data for n-bit unit data in the transmission data;
A feature point extraction unit that extracts feature points where the difference data is greater than a predetermined threshold;
A feature point information holding unit for holding feature point information in which the feature point data is associated with an index;
A selection unit that selects the index corresponding to the data of the feature point at the feature point and selects the difference data other than the feature point for the transmission data of the unit after the transmission data in which the feature point is updated When,
An encoding unit that generates n-bit encoded data by encoding the index or the difference data selected by the selection unit;
a second arithmetic unit that generates the encoded arithmetic data of n bits,
The second operation unit performs an operation using the n-bit encoded data generated by the encoding unit and the previous n-bit encoded operation data generated by the second operation unit. And generating the n-bit encoded operation data. A data transmission device that receives transmission data for each predetermined unit and transmits encoded operation data using a signal line of n (= k × m) bits (k and m are natural numbers of 2 or more),
A first calculation unit that generates difference data by taking a difference from m-bit unit data before the m-bit unit data in the transmission data;
A feature point extraction unit that extracts feature points where the difference data is greater than a predetermined threshold;
A feature point information holding unit for holding feature point information in which the feature point data is associated with an index;
A selection unit that selects the index corresponding to the data of the feature point at the feature point and selects the difference data other than the feature point for the transmission data of the unit after the transmission data in which the feature point is updated When,
An encoding unit that encodes the index or the difference data selected by the selection unit to generate m-bit encoded data;
a second arithmetic unit that generates the encoded arithmetic data of m bits,
The second operation unit performs an operation using the m-bit encoded data generated by the encoding unit and the previous m-bit encoded operation data generated by the second operation unit. And generating the m-bit encoded operation data.   5. The data transmission device according to claim 1, wherein the selection unit selects the difference data for transmission data in a unit from which feature points are extracted by the feature point extraction unit.   The selection unit is configured to transmit the feature data from the next unit of transmission data from which the feature point has been extracted by the feature point extraction unit to the unit of transmission data from which a new feature point is extracted again. 5. The data transmission device according to claim 1, wherein the difference data is selected except for the feature point.   The said selection part selects the said index in the said feature point about the transmission data of the unit after the unit which concerns on the notification of this update, when the update of the feature point is notified from the outside. The data transmission device according to claim 1.   The selection unit selects the index at the feature point for transmission data of a unit after the unit from which the new feature point is extracted in response to the feature point being updated. The data transmission device according to claim 1.   5. The data transmission apparatus according to claim 2, wherein the transmission data is image data in RGB format, and each element of RGB is m bits.   The data transmission apparatus according to claim 2 or 4, wherein the transmission data is image data in RGB format, and any two of m-bit elements are color differences.   5. The data transmission apparatus according to claim 2, wherein the transmission data is image data in YUV format, and each element of YUV is m bits.   The second operation unit is configured to perform exclusive operation for each bit of the n-bit encoded data generated by the encoding unit and the previous n-bit encoded operation data generated by the second operation unit. 4. The data transmission apparatus according to claim 3, wherein the n-bit encoded operation data is generated by performing a logical sum.   The second operation unit is configured to perform exclusive operation for each bit of the m-bit encoded data generated by the encoding unit and the previous m-bit encoded operation data generated by the second operation unit. 5. The data transmission apparatus according to claim 4, wherein a logical sum is taken to generate the m-bit encoded operation data. The encoding unit encodes the difference data using an encoding table in which the number of bit inversions on the signal line is smaller with respect to the difference data having a higher appearance probability,
In the index, the bit inversion number on the signal line when the index is encoded with the encoding table is smaller than the bit inversion number on the signal line when the threshold is encoded with the encoding table. 14. The data transmission device according to claim 1, wherein a value is used. A data receiving apparatus that receives encoded data for each predetermined unit using an n-bit (n is a natural number of 1 or more) signal line,
A decoding unit that decodes the received n-bit encoded data to generate n-bit decoded data;
A feature point extraction unit that extracts feature points at which the decoded data is larger than a predetermined threshold;
A feature point information holding unit for holding feature point information in which the feature point data and the index are associated;
an arithmetic unit for generating arithmetic data in units of n bits;
For the encoded data of the unit after the encoded data in which the feature point is updated, the feature point data corresponding to the index indicated by the decoded data of the feature point is the feature point information. A selection unit that selects the calculation data other than the feature points, and outputs the selected data as selection data in units of n bits.
The operation unit adds the n-bit unit decoded data generated by the decoding unit and the n-bit unit selection data output from the selection unit before the operation data in the n-bit unit. Generate and
A data receiving apparatus, wherein the selection data is received data. A data receiving apparatus that receives encoded data for each predetermined unit using a signal line of n (= k × m) bits (k and m are natural numbers of 2 or more),
A decoding unit that decodes the received m-bit encoded data to generate m-bit decoded data;
A feature point extraction unit that extracts feature points at which the decoded data is larger than a predetermined threshold;
A feature point information holding unit for holding feature point information in which the feature point data and the index are associated;
an arithmetic unit for generating arithmetic data in units of m bits;
For the encoded data of the unit after the encoded data in which the feature point is updated, the feature point data corresponding to the index indicated by the decoded data of the feature point is the feature point information. A selection unit that selects the operation data other than the feature points, and outputs the selected data as selection data in units of m bits;
The arithmetic unit adds the m-bit unit decoded data generated by the decoding unit and the m-bit unit selection data output from the selection unit before the arithmetic data in the m-bit unit. Generate and
A data receiving apparatus, wherein the selection data is received data. A data receiving device that receives encoding operation data for each predetermined unit using an n-bit (n is a natural number of 1 or more) signal line,
A second operation unit that performs an operation using the received n-bit encoded operation data and the previously received n-bit encoded operation data to generate n-bit second operation data;
A decoding unit for decoding the second operation data to generate n-bit unit decoded data;
A feature point extraction unit that extracts feature points at which the decoded data is larger than a predetermined threshold;
A feature point information holding unit for holding feature point information in which the feature point data and the index are associated;
a first arithmetic unit that generates first arithmetic data in units of n bits;
For encoded operation data in units after the encoded operation data in which the feature points have been updated, the feature point data corresponding to the index indicated by the decoded data of the feature points in the feature points. A selection unit that selects from the point information, selects the first calculation data other than the feature points, and outputs the selected data as selection data in units of n bits,
The first calculation unit adds the n-bit unit decoded data generated by the decoding unit and the n-bit unit selection data output from the selection unit before the first calculation unit. Generate data,
A data receiving apparatus, wherein the selection data is received data. A data receiving apparatus that receives encoding operation data for each predetermined unit using a signal line of n (= k × m) bits (k and m are natural numbers of 2 or more),
A second operation unit that performs an operation using the received m-bit encoded operation data and the previously received m-bit encoded operation data to generate m-bit second operation data;
A decoding unit that decodes the second operation data to generate decoded data in m-bit units;
A feature point extraction unit that extracts feature points at which the decoded data is larger than a predetermined threshold;
A feature point information holding unit for holding feature point information in which the feature point data and the index are associated;
a first calculation unit that generates first calculation data in units of m bits;
For encoded operation data in units after the encoded operation data in which the feature points have been updated, the feature point data corresponding to the index indicated by the decoded data of the feature points in the feature points. A selection unit that selects from the point information, selects the first calculation data other than the feature points, and outputs the selected data as selection data in units of m bits;
The first calculation unit adds the m-bit unit decoded data generated by the decoding unit and the m-bit unit selection data output from the selection unit before the first calculation unit. Generate data,
A data receiving apparatus, wherein the selection data is received data.   17. The data receiving apparatus according to claim 15, wherein the selection unit selects the calculation data for the encoded data from which the feature points have been extracted by the feature point extraction unit.   The data reception according to claim 17 or 18, wherein the selection unit selects the first calculation data for the encoded calculation data from which the feature points are extracted by the feature point extraction unit. apparatus.   The selection unit includes the feature point in the feature point from the encoded data of the next unit of the encoded data from which the feature point has been extracted by the feature point extracting unit to the encoded data of the unit in which the feature point is newly extracted. 17. The data receiving apparatus according to claim 15, wherein data of the feature point in point information is selected, and the calculation data is selected other than the feature point.   The selection unit includes, from the encoded calculation data of the next unit of the encoded calculation data unit from which the feature points have been extracted by the feature point extraction unit to the encoded calculation data of a unit from which a feature point is newly extracted. The data reception according to claim 17 or 18, wherein data of the feature point in the feature point information is selected at a feature point, and the first calculation data is selected at a point other than the feature point. apparatus.   When the update of the feature point is notified from the outside, the selection unit, for the encoded data of the unit after the unit related to the notification of the update, the data of the feature point in the feature point information in the feature point The data receiving device according to claim 15 or 16, wherein the data receiving device is selected.   When the update of the feature point is notified from the outside, the selection unit, for the encoded calculation data of the unit after the unit related to the notification of the update, the feature point in the feature point information in the feature point The data receiving apparatus according to claim 17 or 18, wherein data is selected.   In response to the feature point being updated, the selection unit is configured to use the feature point in the feature point information for the encoded data of the unit after the unit from which the new feature point is extracted. The data receiving apparatus according to claim 15 or 16, wherein the data is selected.   In response to the update of the feature point, the selection unit is configured to add, in the feature point, the feature in the feature point information with respect to coding operation data of a unit after the unit from which the new feature point is extracted. 19. The data receiving apparatus according to claim 17, wherein point data is selected.   The second arithmetic unit obtains the second arithmetic data by performing an exclusive OR for each bit of the received n-bit encoded arithmetic data and the previously received n-bit encoded arithmetic data. The data receiving device according to claim 18, wherein:   The second arithmetic unit obtains the second arithmetic data by taking a bitwise exclusive OR of the received m-bit encoded arithmetic data and the previously received m-bit encoded arithmetic data. The data receiving device according to claim 19, wherein A data transmitting apparatus that receives transmission data for each predetermined unit and transmits encoded data using an n-bit (n is a natural number of 1 or more) signal line; and a data receiving apparatus that receives the encoded data A data transmission system comprising:
The data transmission device includes:
For the n-bit unit data in the transmission data, a transmission-side arithmetic unit that generates difference data by taking a difference from the previous n-bit unit data;
A transmission-side feature point extraction unit that extracts feature points for which the difference data is greater than a predetermined threshold;
A transmission-side feature point information holding unit that holds transmission-side feature point information in which the feature point data and the index are associated;
For transmission data in units after transmission data from which a new feature point has been extracted by the transmission-side feature point extraction unit, the index corresponding to the feature point data is selected at the feature point, and other than the feature point A transmission side selection unit for selecting the difference data in
An encoding unit that encodes the index or the difference data selected by the transmission side selection unit to generate the encoded data of n bits,
The data receiving device is:
A decoding unit that decodes the received n-bit encoded data to generate n-bit decoded data;
A receiving-side feature point extracting unit that extracts feature points at which the decoded data is larger than a predetermined threshold;
A receiving-side feature point information holding unit for holding receiving-side feature point information in which the feature point data and the index are associated;
a receiving side arithmetic unit for generating arithmetic data in units of n bits;
For encoded data in units after encoded data from which a new feature point has been extracted by the reception-side feature point extraction unit, the feature point corresponds to the index indicated by the decoded data of the feature point. Selecting a feature point data from the reception side feature point information, selecting the operation data other than the feature point, and outputting the selected data as selection data in units of n bits,
The reception-side arithmetic unit adds the n-bit unit decoded data generated by the decoding unit and the n-bit unit selection data output from the reception-side selection unit before the n-bit unit data Generate computation data for
A data transmission system, wherein the selection data is received data. A data transmission device that receives transmission data for each predetermined unit and transmits encoded data using a signal line of n (= k × m) bits (k and m are natural numbers of 2 or more), and the encoded data A data transmission system comprising a data receiving device for receiving
The data transmission device includes:
For the m-bit unit data in the transmission data, a transmission-side arithmetic unit that generates difference data by taking a difference from the previous m-bit unit data;
A transmission-side feature point extraction unit that extracts feature points for which the difference data is greater than a predetermined threshold;
A transmission-side feature point information holding unit that holds transmission-side feature point information in which the feature point data and the index are associated;
For transmission data in units after transmission data from which a new feature point has been extracted by the transmission-side feature point extraction unit, the index corresponding to the feature point data is selected at the feature point, and other than the feature point A transmission side selection unit for selecting the difference data in
An encoding unit that encodes the index or the difference data selected by the transmission side selection unit to generate the encoded data of m bits;
The data receiving device is:
A decoding unit that decodes the received m-bit encoded data to generate m-bit decoded data;
A receiving-side feature point extracting unit that extracts feature points at which the decoded data is larger than a predetermined threshold;
A receiving-side feature point information holding unit for holding receiving-side feature point information in which the feature point data and the index are associated;
a receiving side arithmetic unit for generating arithmetic data in units of m bits;
For encoded data in units after encoded data from which a new feature point has been extracted by the reception-side feature point extraction unit, the feature corresponding to the index indicated by the decoded data of the feature point in the feature point Selecting a point data from the reception side feature point information, selecting the calculation data other than the feature point, and outputting the selected data as selection data in m-bit units,
The reception-side arithmetic unit adds the m-bit unit decoded data generated by the decoding unit and the m-bit unit selection data output from the reception-side selection unit before adding the m-bit unit data Generate computation data for
A data transmission system, wherein the selection data is received data. A data transmission device that receives transmission data for each predetermined unit and transmits encoded operation data using an n-bit (n is a natural number of 1 or more) signal line, and a data reception device that receives the encoded operation data A data transmission system comprising:
The data transmission device includes:
A first transmission-side arithmetic unit that generates difference data by taking a difference from n-bit unit data before the data for n-bit unit data in the transmission data;
A transmission-side feature point extraction unit that extracts feature points for which the difference data is greater than a predetermined threshold;
A transmission-side feature point information holding unit for holding transmission-side feature point information in which the feature point data is associated with an index;
For transmission data in units after transmission data from which a new feature point has been extracted by the transmission-side feature point extraction unit, the index corresponding to the feature point data is selected at the feature point, and other than the feature point A transmission side selection unit for selecting the difference data in
An encoding unit for generating n-bit encoded data by encoding the index or the difference data selected by the transmission side selection unit;
a second transmission side arithmetic unit that generates the encoded arithmetic data of n bits,
The second transmission side arithmetic unit uses the n-bit encoded data generated by the encoding unit and the previous n-bit encoded arithmetic data generated by the second arithmetic unit. To generate the n-bit encoded operation data,
The data receiving device is:
A second receiving-side arithmetic unit that performs an operation using the received n-bit encoded operation data and the previously received n-bit encoded operation data to generate n-bit second operation data When,
A decoding unit for decoding the second operation data to generate n-bit unit decoded data;
A receiving-side feature point extracting unit that extracts feature points at which the decoded data is larger than a predetermined threshold;
A receiving-side feature point information holding unit for holding receiving-side feature point information in which the feature point data and the index are associated;
a first receiving side arithmetic unit for generating first arithmetic data in units of n bits;
For the encoded calculation data in units after the encoded calculation data from which a new feature point has been extracted by the reception-side feature point extraction unit, the feature point corresponds to the index indicated by the decoded data of the feature point. Selecting the feature point data from the reception side feature point information, selecting the first calculation data other than the feature point, and outputting the selected data as selection data in units of n bits; Have
The first reception side arithmetic unit adds the n-bit unit decoded data generated by the decoding unit and the n-bit unit selection data output from the reception side selection unit before adding the decoded data. Generating first calculation data;
A data transmission system, wherein the selection data is received data. A data transmission apparatus that receives transmission data for each predetermined unit and transmits encoded operation data using a signal line of n (= k × m) bits (k and m are natural numbers of 2 or more), and the encoding A data transmission system comprising a receiving device for receiving operation data,
The data transmission device includes:
A first transmission side calculation unit that generates difference data by taking a difference from m-bit unit data before the m-bit unit data in the transmission data;
A transmission-side feature point extraction unit that extracts feature points for which the difference data is greater than a predetermined threshold;
A transmission-side feature point information holding unit for holding transmission-side feature point information in which the feature point data is associated with an index;
For transmission data in units after transmission data from which a new feature point has been extracted by the transmission-side feature point extraction unit, the index corresponding to the feature point data is selected at the feature point, and other than the feature point A transmission side selection unit for selecting the difference data in
An encoding unit that encodes the index or the difference data selected by the transmission side selection unit to generate m-bit encoded data;
a second transmission side arithmetic unit that generates the encoded arithmetic data of m bits,
The second transmission side arithmetic unit uses the m-bit encoded data generated by the encoding unit and the previous m-bit encoded arithmetic data generated by the second transmission side arithmetic unit. To generate the m-bit encoded operation data,
The data receiving device is:
A second receiving side arithmetic unit that performs an operation using the received m-bit encoded operation data and the previously received m-bit encoded operation data to generate m-bit second operation data When,
A decoding unit that decodes the second operation data to generate decoded data in m-bit units;
A receiving-side feature point extracting unit that extracts feature points at which the decoded data is larger than a predetermined threshold;
A receiving-side feature point information holding unit for holding receiving-side feature point information in which the feature point data and the index are associated;
a first receiving-side arithmetic unit that generates first arithmetic data in units of m bits;
For the encoded calculation data in units after the encoded calculation data from which a new feature point has been extracted by the reception-side feature point extraction unit, the feature point corresponds to the index indicated by the decoded data of the feature point. Selecting the feature point data from the reception side feature point information, selecting the first calculation data other than the feature point, and outputting the selected data as selection data in units of m bits; Have
The first reception-side arithmetic unit adds the m-bit unit decoded data generated by the decoding unit and the m-bit unit selection data output from the reception side selection unit before adding the decoded data. Generating first calculation data;
A data transmission system, wherein the selection data is received data. The second transmission side arithmetic unit is configured to perform bit-by-bit comparison between the n-bit encoded data generated by the encoding unit and the previous n-bit encoded arithmetic data generated by the second arithmetic unit. Taking the exclusive OR to generate the encoded operation data,
The second receiving-side arithmetic unit takes a bitwise exclusive OR of the received n-bit encoded arithmetic data and the previously received n-bit encoded arithmetic data. 32. The data transmission system according to claim 31, wherein operation data is generated. The second transmission side arithmetic unit is configured to perform bit-by-bit comparison between the m-bit encoded data generated by the encoder and the previous m-bit encoded arithmetic data generated by the second arithmetic unit. Taking the exclusive OR to generate the encoded operation data,
The second receiving side arithmetic unit takes an exclusive OR for each bit of the received m-bit encoded arithmetic data and the previously received m-bit encoded arithmetic data. The data transmission system according to claim 32, wherein the data is generated. The data transmission device is a system LSI,
The data receiving device is a display device,
The transmission data for each predetermined unit is image data for each frame,
The said transmission side feature point extraction part and the said reception side feature point extraction part extract feature points only in the specific area | region of the said display device, The Claim 29 thru | or 32 characterized by the above-mentioned. Data transmission system. The transmission side feature point information holding unit holds the feature point information preferentially from feature points having a large value of the difference data,
The data transmission according to any one of claims 29 to 32, wherein the reception-side feature point information holds the feature point information preferentially from feature points having a large value of the decoded data. system. A data transmission method for receiving transmission data for each predetermined unit and transmitting encoded data using an n-bit (n is a natural number of 1 or more) signal line,
An operation step of generating difference data for n-bit unit data in the transmission data by taking a difference from the previous n-bit unit data;
A feature point extracting step of extracting feature points at which the difference data is greater than a predetermined threshold;
A feature point information holding step for holding feature point information in which the feature point data and the index are associated with each other;
For transmission data in units after transmission data from which a new feature point has been extracted in the feature point extraction step, the index corresponding to the data of the feature point is selected at the feature point, and the transmission data other than the feature point A selection step for selecting difference data;
An encoding step for generating the encoded data of n bits by encoding the index or the difference data selected in the selection step;
A data transmission method characterized by comprising: A data transmission method for receiving transmission data for each predetermined unit and transmitting encoded data using a signal line of n (= k × m) bits (k and m are natural numbers of 2 or more),
An operation step of generating difference data by taking a difference between the m-bit unit data in the transmission data and the previous m-bit unit data;
A feature point extracting step of extracting feature points at which the difference data is greater than a predetermined threshold;
A feature point information holding step for holding feature point information in which the feature point data and the index are associated with each other;
A selection step of selecting the index corresponding to the data of the feature point at the feature point and selecting the difference data other than the feature point for the transmission data of the unit after the transmission data in which the feature point is updated When,
An encoding step of encoding the index or the difference data selected in the selection step to generate the encoded data of m bits;
A data transmission method characterized by comprising: A data transmission program that accepts transmission data for each predetermined unit and transmits encoded data using an n-bit (n is a natural number of 1 or more) signal line.
An operation step of generating difference data for n-bit unit data in the transmission data by taking a difference from the previous n-bit unit data;
A feature point extracting step of extracting feature points at which the difference data is greater than a predetermined threshold;
A feature point information holding step for holding feature point information in which the feature point data and the index are associated with each other;
For transmission data in units after transmission data from which a new feature point has been extracted in the feature point extraction step, the index corresponding to the data of the feature point is selected at the feature point, and the transmission data other than the feature point A selection step for selecting difference data;
An encoding step for generating the encoded data of n bits by encoding the index or the difference data selected in the selection step;
A data transmission program characterized in that A data transmission program that accepts transmission data for each predetermined unit and transmits encoded data using a signal line of n (= k × m) bits (k and m are natural numbers of 2 or more). ,
An operation step of generating difference data by taking a difference between the m-bit unit data in the transmission data and the previous m-bit unit data;
A feature point extracting step of extracting feature points at which the difference data is greater than a predetermined threshold;
A feature point information holding step for holding feature point information in which the feature point data and the index are associated with each other;
A selection step of selecting the index corresponding to the data of the feature point at the feature point and selecting the difference data other than the feature point for the transmission data of the unit after the transmission data in which the feature point is updated When,
An encoding step of encoding the index or the difference data selected in the selection step to generate the encoded data of m bits;
A data transmission program characterized in that