Image recording apparatus

• US 5,568,284 A
• Filed: 08/05/1994
• Issued: 10/22/1996
• Est. Priority Date: 03/27/1991
• Status: Expired due to Term

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Kubo, Masahiro, Tatsumi, Setsuji, Oku, Seiichiro
• Primary Examiner(s): Coles, Sr., Edward L.
• Assistant Examiner(s): LEE, TOMMY D
• Application Number:
  US08/286,232
• Time in Patent Office: 809 Days
• Field of Search: 358/501, 358/504, 358/518, 358/520, 358/524, 358/530, 358/443, 358/448, 358/458, 395/100, 395/101, 395/109, 395/114, 395/118, 395/131
• US Class Current: 358/518
• CPC Class Codes: H04N 1/60 Colour correction or control H04N1/54 takes precedence
• CPC Class Codes: H04N 1/6019 using look-up tables H04N1/6025 takes precedence

Abstract

An image recording apparatus with good color reproduction and easy color adjusting function. An image recording apparatus includes a first color correction unit coupled to receive image signals from the image signal source, a second color correction unit coupled to receive output image signals of the first color correction unit, and a third color correction unit coupled to receive output image signals of the second color correction unit. The image recording apparatus further includes an adjusting device for at least the first color correction unit and the third color correction unit, and an adjustment information entering device. Good color reproduction is realized with color correction and data compression, and is not accompanied by hue change in color perception. Manufacturing variations in the color output unit are corrected by the third color correction unit. Easy setting of the reference for color adjustment independently of the input image signals is also realized by the unit.

Claims

1. A method employed by an image recording apparatus, which receives image signals representing colors, for compressing a color reproduction region of the image recording apparatus in a uniform color space, comprising the step of compressing said colors outside the color reproduction region onto a surface of the color reproduction region at respective points, which represent the minimum color difference between said colors before and after compression, without changing the color tint of said colors, said compressing step further comprising the steps of:

plotting those of said colors whose color shape appears to be of the same hue on a plane of a* and b* in a color space of L*, a* and b*, so that the resultant loci are curve-approximated by functions; and

moving, according to the curve-approximated loci, an intended color to project the colors onto their respective points of the minimum color difference between the colors before and after compression without varying the color tint.

2. A method employed by an image recording apparatus, which receives image signals representing colors, for compressing a color reproduction region of the image recording apparatus in the R, G and B fundamental tristimulus values, the method comprising the steps of:

calculating R'"'"', G'"'"' and B'"'"' fundamental tristimulus values of an image for recording based on said R, G and B fundamental tristimulus values;

determining whether said R'"'"', G'"'"' and B'"'"' fundamental tristimulus values are outside said color reproduction region; and

adjusting the tristimulus values R_pw, G_pw and B_pw of white for the image recording apparatus when said R'"'"', G'"'"' and B'"'"' fundamental tristimulus values are determined to be outside said color reproduction region to cause those of said colors which are outside said color reproduction region to correspond to colors inside said color reproduction region.