Dainippon Screen Mfg. Co., Ltd.

Screen Holdings Co., Ltd.

Akihiro Nomura

Yasuo Kurusu

Takashi Sakamoto

Masamichi Cho

Kunio Tomohisa

Kazutaka Taniguchi

Nobuhiro Takita

By deleting a small area from an initial boundary image, a provisional boundary image is obtained (Step S). A thinning processing is performed on the provisional boundary image to shape the image, and a thickening processing is performed on the thinned image to obtain a mask image (Steps Sto S). By masking the initial boundary image with the mask image, an updated provisional boundary image is obtained (Step S). In the updated provisional boundary image, end points adjacent to each other are connected (Step S). By repeating Steps Sto S, a broken boundary is repaired. As a result, even if a boundary of a cell colony is blurred, an area of the cell colony can be specified easily and efficiently.

Cell colony area specifying apparatus, cell colony area specifying method, and recording medium

The method of the present invention first provides a plurality of representative color points existing on the surface of a gamut (s20), and sets a plurality of boundary lines that connect the plurality of representative color points substantially along the surface of the gamut (s22). The method subsequently defines a plurality of unit faces that are respectively surrounded by at least three boundary lines and arranged substantially along the surface of the gamut (s24), and sets a color plane to cross the gamut (s26). The method successively selects cross boundary lines that cross the color plane among the plurality of boundary lines, determines intersections of the cross boundary lines and the color plane, selects unit faces that cross the color plane based on the selected cross boundary lines, specifies cross lines of the selected unit faces and the color plane by connecting the intersections, and joins the cross lines to extract a contour of a cross plane area obtained by causing the color plane to cross the gamut (s28). This structure enables the contour of a cross plane area, which is obtained by causing a color plane to cross the gamut, to be accurately extracted even when the color plane is arranged at any arbitrary position and in any arbitrary orientation.

Method of and apparatus for extracting cross plane area of gamut and

Experiential gradation correction curves for sample images are prepared. By analyzing the experiential gradation correction curves and accumulated density histograms of the sample images, two points (Y.sub.1, Q.sub.1) and (Y.sub.2, Q.sub.2) are specified, where Y.sub.1 and Y.sub.2 are values of accumulated occurrence and Q.sub.1 and Q.sub.2 are halftone dot percentages for image reproduction. The values Y.sub.1 and Y.sub.2 through an accumulated density histogram of an original image whose gradation is to be corrected. A gradation correction curve Q=G(x) is determined so as to pass through the two points (x.sub.1, Q.sub.1) and (x.sub.2, Q.sub.2).

Method of generating gradation correction curve for correcting gradation

Highlight density (X.sub.H) (or shadow density) is established on the basis of a cumlative histogram (H(X)) of density of an original. Computed first are reference densities (X.sub.HR, X.sub.HL and X.sub.Hl -X.sub.Hn) associated with prescribed reference statistic values (Y.sub.HR, Y.sub.HL and Y.sub.Hl -Y.sub.Hn), respectively, and threshold values (W.sub.Hl -W.sub.Hn). Then, the reference density (X.sub.HR) is compared with a prescribed threshold density (X.sub.HS), and a difference (X.sub.Hi) concerning the reference density (X.sub.Hi) is compared with the threshold value (W.sub.Hi) in a procedure, to thereby select one of procedures for establishing the highlight density.

Method of and apparatus for establishing highlight and shadow densities

A standard gradation correction curve independent of characteristics of an original image is prepared in advance. An accumulated density historgram curve of the original is obtained from image data of the original. A first gradation correction curve is obtained by modifying the standard gradation correction curve, while a second gradation correction curve is obtained by modifying the accumulated density histogram curve. A third gradation correction curve is obtained by linear combination of the first and second gradation conversion curves to perform gradation correction of the image data on the basis of the third gradation correction curve.

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Kyoto, Japan

Akihiro Nomura