| 摘要 |
PURPOSE:To remarkably increase a transmission speed without spoiling the contents of an image by varying the transmission image data quantity in accordance with a frequency component of an image signal at the time of transmission. CONSTITUTION:An image signal which has been inputted to a transmitting part is converted to a digital signal by a sampling frequency 4fsc (14.32MHz), and stored in a video memory 3 through a switch 9. The image signal which has been stored in the video memory 3 detects a frequency component at every horizontal scanning line, and data is thinned out by a Nyquist frequency corresponding to a frequency band on its scanning line. Therefore, the transmission image data quantity can be compressed remarkably. In such a way, the transmission speed can be increased to several times of a conventional one. |
