| 摘要 |
<p>There is disclosed an apparatus capable of transmitting a moving image with smooth movement and with sufficient image quality, even through a transmission channel of a low bit rate. In this apparatus, with the received image, a significant area to be received with high image quality is designated on a monitor image frame. The image signal to be transmitted is entered, in the unit of a block, into an input terminal 40. Circuits 42 - 48, 52 - 58 constitute a frame-to-frame difference encoding circuit. A subtractor 42 releases the predicted error, and a DCT circuit 44 releases the DCT transformation coefficients. A masking circuit 46 masks the DCT coefficients released from the DCT circuit 44, in a smaller proportion in a block belonging to the significant area, and in a larger proportion in a block belonging to the non-significant area, according to the mask level signal 47. A quantization circuit 48 quantizes the output of the masking circuit 46. <IMAGE></p> |
