公开(公告)号：JPH04370881A

公开(公告)日：1992-12-24

申请号：JP17474991

申请日：1991-06-20

Applicant: IBM

Inventor： KO MASAKUNI ,  TAKAHASHI HIROYASU ,  SATO MACHIKO

IPC: G06T7/00 ,  G06F17/30 ,  G06T1/00 ,  G06T5/00

Abstract: PURPOSE: To highly and certainly retrieve a color area by constituting a tree structural data reaching a root node by using a block including at least one picture element in a color picture area as a leaf node, and applying a color index based on a sensory color system to each node. CONSTITUTION: A color system converter 20 of a tree structural data preparing unit 2 converts RGB data 28 of each picture element of a memory 26 into HLS(hue, lightness, and saturation) data 30 of a sensory color system. A color class deciding device 22 divides the color space of the sensory color system into color classes, and decides color class data 32 of each picture element. A tree structural data converter 24 prepares a tree structure in which the least significant level is defined as a leaf node NB110 and the most significant level is defined as a root node NB by using, for example, a four divided-tree. A minimum block B110 corresponding to the leaf node NB110 is constituted of, for example, four picture elements, and the color index of the leave node NB110 is decided from the color class of each picture element. Then, the color index is applied to each node from the lower rank node to the upper rank node reaching the root node NB.