The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 15, 1995
Filed:
Mar. 30, 1993
Shigeo Murakami, Kyoto, JP;
Dainippon Screen Mfg. Co., Ltd., Kyoto, JP;
Abstract
A sharpness processing apparatus for enhancing or suppressing tone variations in an original image. A lookup table for converting RGB signals into HSL values which are the three attributes of perceived colors is used to obtain HLS values of pixels in the original image stored in a frame memory. The HSL values of the pixels are successively compared with HSL values indicating an effective range of sharpness processing determined with reference to a designated reference color, to determine pixels to be subjected to the processing. The processing is effected by applying a parameter to the RGB signals of the pixels subjected to the processing. In this way, the apparatus facilitates designation of a region of sharpness processing. Besides, the value of the parameter is variable with differences between the HSL values of the pixels corresponding to the reference color and the HSL values of the pixels determined to be subjected to the processing, whereby the sharpness processing is effected without impairing smoothness of the original image.