Ricoh Company, Ltd.

Arata Yamaguchi

Takashi Kimura

Masakazu Yoshida

Takayuki Ito

Hiroaki Sagae

Masanori Hirano

Yoshihisa Ohta

Shigetaka Sakakibara

An image processing apparatus is disclosed. The image processing apparatus includes a color conversion processing unit which obtains CMY data from input color space coordinate data of image data, and an output data generating unit which generates output data by forming CMYK data by using a result output from a color conversion processing section. The color conversion processing section includes an optimum color reproduction data structure which gives the CMY data for obtaining a full color image optimally reproduced from the input color space coordinate data, and a color material using amount reducing data structure for outputting the input color space coordinate data by reducing the color material using amount with the use of a reference value in which the color material using amount is increased for a hue of an output image giving a high psychological effect and is decreased for a hue of the output image giving a low psychological effect.

Image processing apparatus, image processing method, and computer-readable recording medium storing image processing program for color conversion of image data

An image processing apparatus quantizes multi-level image data of n colors, where n&#x2267;2, by performing an error diffusion processing. The image processing apparatus includes: a dot arrangement determining unit that determines either one of an essential dot count and an essential recording material amount when the multi-level image data of n colors is converted into multi-level image data of m colors, where n&#x3e;m&#x2267;1, by the error diffusion processing; and a color arrangement determining unit that performs the error diffusion processing on each color component of the multi-level image data of n colors, calculates either one of a dot count and a recording material amount for each color component, and determines an arrangement of either one of the dot count and the recording material amount for each color component within a range of a corresponding one of the essential dot count and the essential recording material amount determined by the dot arrangement determining unit.

Image processing apparatus and method for determining arrangement of dot count or recording material amount by error diffusion process

An image processing apparatus, which performs an error diffusion on M-value image data with an error weight matrix into N-value image data, includes: a corrected-value calculating unit that calculates a corrected value by adding a first value and a second value to a pixel value corresponding to a processing-target color component of a pixel of interest, the first value being obtained by multiplying an error for each quantized pixel of the processing-target color component by the matrix, and the second value being obtained by multiplying an error for each quantized pixel of a different color component by the matrix; a quantizing unit that compares the corrected value with a quantization threshold, and outputs N-value image data; and an error diffusion unit that calculates an error at the pixel of interest by subtracting a quantization threshold from a value obtained by adding the first value to the pixel value.

Image processing apparatus, image processing method, and computer program product

Growing community of inventors

Tokyo, Japan

Arata Yamaguchi