Letter-box transformation device

摘要

A read control circuit reads image data, which are stored in a decoding image memory, at a read speed m/n times a display speed. These image data are written to line memories by a write control circuit. A read-address control circuit reads the image data from the line memories at a display speed, and line data for a letter-box image are generated by multipliers and an adder. Specifically, the line data of m lines which are read from the decoding image memory are transformed to n lines so that a letter-box display is made possible. Thus, letter-box transformation processing is performed with less memory capacity without the use of a field memory.