Sharp Kabushiki Kaisha Corporation

Tomoe Matsuoka

Kyosuke Taka

Michiko Fujiwara

Tatsuya Tanaka

Yasutaka Maeda

Takashi Usui

Masayasu Narimatsu

Hideyoshi Yoshimura

Makoto Uehara

Ken Yamagishi

Norihide Yasuoka

Yuka Sakagami

Hiroji Kawamoto

A local density calculation section calculates a density of a pixel region with a predetermined size including a current point of an input image disposed at the center on the basis of a pixel value of the pixel region. A mixing ratio calculation section generates a coefficient set of coefficients &#x3b1; and &#x3b2; in accordance with a local density value calculated by the local density calculation section, and outputs the generated coefficients &#x3b1; and &#x3b2; to a weight process section. The weight process section multiplies an operation result obtained from the input image by a first filter operation section by the coefficient &#x3b1;, multiplies an operation result obtained from the input image by a second filter operation section by the coefficient &#x3b2;, adds the multiplied results to each other and outputs the result of addition as a process result of a spatial filter process section.

Using separate coefficients to weight and add separate images together from a spatial filter process

In the case where an output value of a document reading section for at least any of R, G and B is out of a range between a first reference value and a second reference value due to a change in an output value of a reading device caused by an electrical noise, a change of supply voltage, etc. when a document is being read, a second color conversion table is created in accordance with the above change by expanding ranges in a first color conversion table, which ranges are around predetermined first and second reference values and included in regions of RGB color system associated respectively with predetermined tone values of Y, M and C. Using the second color conversion table thus obtained, a color conversion is carried out from the RGB color system into the YMC color system.

Image processing method and image processing apparatus

An image processing apparatus includes: a document type automatic classification section which determines whether input image data is image data for a text document or not; a newspaper document classification section which determines whether the input image data is image data for a newspaper document or not; a segmentation process section which identifies a page-background region in the input image data; and a color correction section for, if the input image data is classified as the text document and but not the newspaper document and if a page-background removal process is to be performed to the input image data, performing a first page-background removal process to the image data, but if the input image data is classified as the text document and the newspaper document, not performing the first page-background removal process to the image data. This makes it possible to prevent deterioration of visual sharpness of the text in the document image printed on the newspaper.

Image processing apparatus and method including page-background process capability, and non-transitory computer readable storage medium for causing computer to function as the same

An image processing apparatus of the present invention includes: a signal correction means which corrects, in an RGB color space, RGB tone data which is RGB image data; and a comparison section which compares (i) a tonal value of a white point which is neither an origin nor maximum tonal values of R, G, and B in the RGB color space, and where tonal values of R, G, and B are identical to one another, with (ii) respective tonal values of R, G, B of the RGB tone data. (A) In case where the tonal values of R, G, and B are determined to be larger than the white point, the signal correction means corrects the tonal values of R, G, and B to be close to the white point. (B) In case where the tonal values of R, G, and B of the RGB tone data is determined to be smaller than the white point, the signal correction section corrects they tonal values of R, G, and B of the RGB tone data to be away from the white point. As a result, undercolor processing is precisely executed while the color reproducibility in a highlight is maintained.

Image processing apparatus, image forming apparatus, control program, and computer-readable recording medium

An image forming apparatus including a developing unit for stocking a developing agent containing toner and forming a toner image on a photosensitive medium with the developing agent, a toner supply unit for supplying the toner to the developing unit, a toner specific concentration detecting unit for detecting the toner specific concentration of the developing agent stocked in the developing unit, a humidity detecting unit for detecting humidity in the neighborhood of the developing unit, a storage unit for storing the humidity information detected by the humidity detecting unit, and a toner specific concentration correcting unit for controlling the toner supply amount of the toner supply unit on the basis of the humidity information stored to correct the toner specific concentration, wherein the toner specific concentration correcting unit compares newly-detected humidity with reference humidity corresponding to the humidity which is detected at the time when the developing agent is stocked into the developing unit or exchanged by new developing agent and which is stored in the storage unit, and corrects the toner specific concentration in accordance with the comparison result.

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Nishinomiya, Japan

Tomoe Matsuoka