| 摘要 |
PROBLEM TO BE SOLVED: To compress a video signal vertically while suppressing a decrease in resolution by sequentially storing line-sequential scan video signals, reading it out by more than one lines at the same time, weighting, adding, and compressing respective signals, and reading them out sequentially in read timing corresponding to a horizontal scanning frequency. SOLUTION: Line memories 1 to 4 which are executable of writing operation and reading operation simultaneously and independently store line-sequential scan video signals in order, and the stored video signals are read out by every N lines at the same time. Then a vertical compression arithmetic circuit 20 weights and adds the respective video signals of N lines and compresses the video signals of the N lines into one line according to an arithmetic mode execution command from a control circuit 10. Further, the compression arithmetic result is written in a buffer memory 30 in order, read out sequentially in the read timing corresponding to the horizontal scanning frequency of the NTSC system, and supplied as a vertically compressed video signal to a D/A converter 40. |
