| 摘要 |
PURPOSE:To improve the picture quality of a specific screen part for displaying important information by increasing forced intra-frame coding frequency at the specific part of the screen. CONSTITUTION:An image signal processing circuit 303 transfers a digital image signal 105 to one FM in each frame and stores the image of the frame transferred immediately before the current frame in the other FM as a reference frame based upon a transfer signal 100 inputted from a coding circuit 308. The circuit 308 codes an image in each block by using the two FMs based upon inter-frame forecasting. In this case, the circuit 308 specifies a block to be set up to a forced INTR mode in a storage circuit of a forced INTR circuit 312. A comparator in the circuit 312 compares the address 107 of the FM indicating a coding block with the output of the storage circuit, and at the time of detecting the coincidence of both the data, outputs a detection signal 109 to the circuit 308. The circuit 308 codes the block by a forced mode. Consequently the picture quality of an important screen can be improved. |
