Image signal processing apparatus and image formation apparatus including the same

U.S. Patent Number: 5387988

Abstract: An image processing apparatus for converting red, green, and blue luminance signals into cyan, magenta, and yellow density signals comprises: a first signal processing circuit for producing the cyan density signal from the red luminance signal; a second signal processing circuit for producing the magenta density signal from the green luminance signal and the cyan density signal; and a third signal processing circuit for producing the yellow density signal from the blue luminance signal, the cyan signal, and the magenta signal. Each of signal processing circuits comprises one or more look-up tables. The table of the second signal processing circuit may include the function of the first signal processing circuit and is supplied with red and green luminance signals. The third signal processing circuit has first and second tables. The first table responds to the cyan density signal and the blue luminance signal. The second table responds to the magenta density signal and the result of the first table. An image formation apparatus including the image signal processing apparatus mentioned above is disclosed also.

Inventors: Hiratsuka; Seiichiro (Kitakyushu, JP), Hayashi; Yoshitsugu (Fukuoka, JP), Yamaguchi; Hiroshi (Fukuoka, JP)

Assignee: Matsushita Electric Industrial Co., Ltd. (JP)

Application Number: 08/055,552

Issued: 1995-02-07

Expired: 2007-02-07

Classes: 358/515 ; 358/518

Field of search: 358/461,475,430,424,423,518,515

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