US 7,321,686 B2
Image processing apparatus and method for improving the contract of an image
Hiroyuki Shibata, Tochigi (Japan); Keiji Tsuchiya, Tochigi (Japan); and Naoto Takahashi, Tochigi (Japan)
Assigned to Canon Kabushiki Kaisha, Tokyo (Japan)
Filed on Nov. 10, 2003, as Appl. No. 10/705,269.
Claims priority of application No. 2002-337127 (JP), filed on Nov. 20, 2002.
Prior Publication US 2004/0136606 A1, Jul. 15, 2004
Int. Cl. G06K 9/00 (2006.01)
U.S. Cl. 382—168  [382/240; 382/226; 382/254; 382/260; 382/274; 375/240; 375/240.01; 375/240.18; 375/240.19; 341/79] 15 Claims
OG exemplary drawing
 
1. An image processing apparatus comprising:
decomposing means for decomposing an image into components of a plurality of frequency bands;
converting means for converting coefficient values with regard to at least one frequency band of the plurality of frequency bands in such a manner that a frequency distribution of coefficient values in the at least one frequency band is rendered substantially flat; and
generating means for generating an image using the coefficient values obtained by said converting means.