| 摘要 |
<p>PROBLEM TO BE SOLVED: To speed up the reproduction of a color picture and to reduce the capacity of a display memory by comparing the number of bits in indexes in a global palette and a local palette and deciding the propriety of the generation of the local palette. SOLUTION: A global palette generation means 6 counts the number of use colors of color picture data 2 and a local palette generation means 9 counts the number of colors in a block. The number of colors in the block is compared with a prescribed value becoming reference at the time of generating the global palette 5. When the prescribed value is set to be 2<n> ((n) is 2<x> when (x) is set to be the integer of not less than '0'), the index in the global palette is expressed by n-bits. when the number of colors in the block is set to be 2<m> ((m) is 2<x> when (x) is set to be the integer of not less than '0', (m) is not less than a specified value and (m) is the integer of not less than the specified value), the index in the local palette is expressed by m-bits. When n=m, the local palette is not generated. When n>m, the local palette is generated.</p> |
