| 摘要 |
<p>PURPOSE:To reduce the communication capacity of coordinate information, by transmitting the values of Y and X in the form of signals A and B when the value of X of the binary X and Y coordinates is less than a prescribed level and transmitting the values of X and Y in the form of signals A and B after the conversion of the value of X when the value of X is larger than the prescribed level respectively. CONSTITUTION:For instance, image resolution in the directions of X and Y axes on a CRT screen is 312 and 200 lines, respectively. X and Y coordinate data are successively transmitted, and accordingly the X and Y coordinates need 2 bytes and 1 byte, respectively. If the image resolution is set within 256 lines for both the X and Y coordinates, just 1 byte suffices for both coordinates. Thus a region II which exceeds 256 lines of the X coordinate is replaced with a region III of 200-255 lines of the Y coordinate and then transmitted to be adversely converted at the receiving side. The data of a regionIof under X=255 and Y= 199 are transmitted in order of Y and X coordinates, and the data of the region II are transmitted in order of X and Y coordinates. The former data is turned, into signal A, and the latter data is turned into signal B respectively. As the signals A and B in the regionIare less than 199 and 255, respectively, the Y and X coordinates are defined. A signal A is transmitted by subtracting 56 from >=256 X value in the region II, and the X coordinate is shown at the receiving side with addition of 56.</p> |
