Image processing apparatus

Claim 2

An image processing apparatus comprising: means for reading a color image to convert it into three primary color data which correspond to the respective densities of the three primary colors; edge detecting means for detecting a pixel of an edge portion based on the three primary color data; pixel color judging means for judging a color of a target pixel based on the three primary color data of the target pixel and pixels adjacent thereto; and black edge detecting means for detecting a pixel of a black edge portion based on an edge detection result applied by the edge detecting means and a pixel color judgment result applied by a pixel color judging means, the pixel color judging means including: first judgment means which, based on the three primary color data of a target pixel, determines a color of the target pixel by selecting from black, white, chromatic color, gray and "assumed-to-be-gray", and second judgment means which judges a color of a target pixel either gray or chromatic color based on a maximum density color of the target pixel and pixel colors and maximum density colors of pixels adjacent thereto, the target pixel having been judged to be "assumed-to-be-gray" by the first judgment means, and wherein selection/judgment conditions of the second judgment means are established based on the characteristics of a pixel color and maximum density color of a pixel of a black edge portion, which characteristics depend upon an arrangement order of color filters in a scanner.

Claim 3

An image processing apparatus comprising: means for reading a color image by means of a scanner to convert it into three primary color data which correspond to the respective densities of the three primary colors; edge detecting means for detecting a pixel of an edge portion based on the three primary color data; pixel color judging means for judging a color of a target pixel based on the three primary colors; and black edge detecting means for detecting a pixel of a black edge portion based on an edge detection result, and on a pixel color and a maximum density color of the target pixel, the pixel color judging means determining a color of a target pixel by selecting from five colors including white, black, chromatic color, gray, and "assumed-to-be-gray" based on the three primary color data of the target pixel, and the black edge detecting means including judgment means which judges a target pixel a black edge pixel if a maximum density color of the target pixel is a maximum density color of a black edge which is determined by an arrangement order of color filters in a scanner, the target pixel having been determined to be an edge pixel by the edge detecting means and judged to be "assumed-to-be-gray" by the pixel color judging means.

Claim 4

An image processing apparatus comprising: means for reading a color image by means of a scanner to convert it into three primary color data which correspond to the respective densities of the three primary colors; edge detecting means for detecting a pixel of an edge portion based on the three primary color data; pixel color judging means for judging a color of a target pixel based on the three primary colors; and black edge detecting means for detecting a pixel of a black edge portion based on an edge detection result, and on a pixel color and a maximum density color of the target pixel, the pixel color judging means determining a color of a target pixel by selecting from five colors including white, black, chromatic color, gray, and "assumed-to-be-gray" based on the three primary color data of the target pixel, and the black edge detecting means including judgment means which judges a target pixel a black edge pixel if a maximum density color of the target pixel is a maximum density color of a black edge which is determined by an arrangement order of color filters in a scanner, the target pixel having been determined to be an edge pixel by the edge detecting means and judged to be "assumed-to-be-gray" by the pixel color judging means.

Claim 5

An image processing apparatus comprising: means for reading a color image by means of a scanner to convert it into three primary color data which correspond to the respective densities of the three primary colors; edge detecting means for detecting a pixel of an edge portion based on the three primary color data; pixel color judging means for judging a color of a target pixel based on the three primary color data; and black edge judging means for determining whether the target pixel is a black edge pixel or not, based on an edge detection result, a pixel color and a maximum density color of the target pixel, and based on edge detection results, pixel colors and maximum density colors of pixels adjacent the target pixel, the pixel color judging means determining a color of a target pixel by selecting from five colors including white, black, chromatic color, gray, and "assumed-to-be-gray" based on the three primary color data of the target pixel, and the black edge judging means including first judgement means which determines whether the target pixel is a black edge pixel or not based on a maximum density color of the target pixel, and based on edge detection results, pixel colors and maximum density colors of pixels adjacent thereto, the target pixel having been judged an edge pixel by the edge detecting means and judged to be "assumed-to-be-gray" by the pixel color judging means, and wherein judgement conditions of the of the first judgment means are established based on the characteristics of a pixel color and a maximum density color of a black edge portion, which characteristics depend upon an arrangement order of color filters in a scanner, and based on the characteristics of an image density of the black edge portion.

Claim 6

An image processing apparatus comprising: means for reading a color image by means of a scanner to convert it into three primary color data which correspond to the respective densities of the three primary colors; edge detecting means for detecting a pixel of an edge portion based on the three primary color data; pixel color judging means for judging a color of a target pixel based on the three primary color data; and black edge judging means for determining whether the target pixel is a black edge pixel or not, based on an edge detection result, a pixel color and a maximum density color of the target pixel, and based on edge detection results, pixel colors and maximum density colors of pixels adjacent the target pixel, the pixel color judging means determining a color of a target pixel by selecting from five colors including white, black, chromatic color, gray, and "assumed-to-be-gray" based on the three primary color data of the target pixel, and the black edge judging means including first judgement means which determines whether the target pixel is a black edge pixel or not based on a maximum density color of the target pixel, and based on edge detection results, pixel colors and maximum density colors of pixels adjacent thereto, the target pixel having been judged an edge pixel by the edge detecting means and judged to be "assumed-to-be-gray" by the pixel color judging means, and wherein judgement conditions of the of the first judgment means are established based on the characteristics of a pixel color and a maximum density color of a black edge portion, which characteristics depend upon an arrangement order of color filters in a scanner, and based on the characteristics of an image density of the black edge portion.

Claim 7

An image processing apparatus comprising: means for reading a color image by means of a scanner to convert it into three primary color data which correspond to the respective densities of the three primary colors; edge detecting means for detecting a pixel of an edge portion based on the three primary color data; pixel color judging means for judging a color of a target pixel based on the three primary color data; and black edge detecting means for detecting a pixel of a black edge portion based on an edge detection result of the edge detecting means and a pixel color judgment result of the pixel color judging means; and detecting means for blurred color pixel adjacent black edge which detects a pixel of a boundary portion between a black edge portion and a base portion, based on a black edge detection result of the black edge detecting means and a pixel color judgement result of the pixel color judging means, the pixel color judging means including: first judgment means for determining a color of a target pixel by selecting from black, white, chromatic color, gray, and "assumed-to-be-gray" based on the three primary color data of the target pixel, and second judgment means which judges a color of the target pixel either gray or chromatic color based on a maximum density color of the target pixel and pixel colors and maximum density colors of pixels adjacent thereto, the target pixel having been judged to be "assumed-to-be-gray" by the first judgment means, and wherein selection/judgment conditions of the second judgment means are established based on the characteristics of a pixel color and a maximum density color of a black edge portion, which characteristics depend upon an arrangement order of color filters in a scanner.

Claim 8

An image processing apparatus comprising: means for reading a color image by means of a scanner to convert it into three primary color data which correspond to the respective densities of the three primary colors; edge detecting means for detecting a pixel of an edge portion based on the three primary color data; pixel color judging means for judging a color of a target pixel based on the three primary color data; and black edge detecting means for detecting a pixel of a black edge portion based on an edge detection result of the edge detecting means and a pixel color judgment result of the pixel color judging means; and detecting means for blurred color pixel adjacent black edge which detects a pixel of a boundary portion between a black edge portion and a base portion, based on a black edge detection result of the black edge detecting means and a pixel color judgement result of the pixel color judging means, the pixel color judging means including: first judgment means for determining a color of a target pixel by selecting from black, white, chromatic color, gray, and "assumed-to-be-gray" based on the three primary color data of the target pixel, and second judgment means which judges a color of the target pixel either gray or chromatic color based on a maximum density color of the target pixel and pixel colors and maximum density colors of pixels adjacent thereto, the target pixel having been judged to be "assumed-to-be-gray" by the first judgment means, and wherein selection/judgment conditions of the second judgment means are established based on the characteristics of a pixel color and a maximum density color of a black edge portion, which characteristics depend upon an arrangement order of color filters in a scanner.

Claim 9

An image processing apparatus as set forth in claim 4, wherein the detecting means for blurred color pixel adjacent black edge includes means for judging blurred color pixel adjacent black edge which determines whether a target pixel is in a boundary portion between a black edge and a base portion, based on a black edge detection result, a pixel color and a maximum density color of the target pixel; a black edge detection result of a next pixel on one side thereof; and a black edge detection result and a pixel color of the next pixel on the other side thereof.

Claim 10

An image processing apparatus as set forth in claim 5, wherein judgment conditions of the means for judging blurred color pixel adjacent black edge are established based on the characteristics of a pixel color and a maximum density color of said boundary portion, which characteristics depend upon an arrangement order of color filters in a scanner, and based on the characteristics of an image density of said boundary portion.