IMAGE TRANSMISSION SYSTEM

摘要

PURPOSE:To transmit an image whose variation part is rough in a short time and to improve picture quality by transmitting an interframe forecasted residual and transmitting the variation pat of the image while picture element intervals are varied from rough intervals to fine intervals. CONSTITUTION:A digital sampling circuit 2 writes an image which is picked up by an image pickup device 1 in a current image frame buffer 3. A multiplying circuit 4 performs multiplication by a specific value M1. The digital value of its reference image data is multiplied by the specific value M1 through a multiplying circuit 6 and the result is inputted to an interframe forecasting circuit 7. A forecasting circuit 7a performs interframe forecasting operation and its forecasted value is stored in an image line buffer 7b and also inputted to a difference circuit 8 to calculate the interframe forecasted residual. A variation residual decision circuit 9 compares it with the 1st set value R4A to decide a variation residual when the residual is larger than the set value R4A or no residual when smaller. A variable sampling density compressing circuit 10 performs encoding operation by the variation residual decision circuit 9 according to quantization characteristics.