| 摘要 |
PROBLEM TO BE SOLVED: To enable completely reversible color conversion by integer operation of predictable precision. SOLUTION: This forward converting device performs forward color conversion for respective (n)-bit RGB inputs by a×2 block 301, adders 302 and 305, subtracters 303 and 304, and a÷block 306 and sends out an (n)-bit Yrev output and (n+1)-bit Urev and Vrev outputs. Those conversion outputs are inputted to, for example, a nonlossy coder, which compresses and then expands them to reproduce the original (n)-bit RGB data by inversely converting the expanded data. Rounding up and off generated in the forward conversion is compensated by the inverse converting process, so errors are not accumulated even when the compression and expansion are repeated.
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