Method and apparatus for detecting image area, and computer product

• US 8,442,312 B2
• Filed: 12/30/2005
• Issued: 05/14/2013
• Est. Priority Date: 06/01/2005
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Moroo, Jun, Noda, Tsugio
• Primary Examiner(s): BEKELE, MEKONEN T
• Application Number:
  US11/322,127
• Publication Number:
  US 20060274339A1
• Time in Patent Office: 2,692 Days
• Field of Search: 358/520, 358/518, 358/524, 358/539, 358/1.9, 358/523, 358/534, 358/525, 358/515, 358/296, 358/300, 358/500, 358/504, 358/1.1, 358/3.32, 358/2.1, 382/162, 382/165, 382/166, 382/167, 382/100, 382/163, 382/232, 382/274, 382/275, 382/30, 382/300, 382/293, 382/276, 348/606, 348/631, 348/653, 348/662, 348/663, 348/713, 348/E9.047, 348/279, 348/E9.04, 345/602, 345/603, 345/604, 345/600, 345/594, 345/590, 345/601, 345/609, 345/589, 345/77
• US Class Current: 382/167
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 1/32352 Controlling detectability or arrangements to facilitate detection or retrieval of the embedded information, e.g. using markers for decoding, detection or retrieval operations H04N1/32149 and subgroups take precedence
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes

Abstract

An apparatus detects an area specified based on a mark of a specific color out of three primary colors in pigment or three primary colors in light from an image. An other-color-information eliminating unit eliminates information of other colors from a tone level of the specific color by correcting the tone level of the specific color based on tone levels of two colors other than the specific color out of the three primary colors in pigment or the three primary colors in light. An area detecting unit detects the area by specifying the mark based on the tone level from which the information of other colors is eliminated.

Claims

1. An apparatus that detects an area specified based on a mark of a specific color out of three primary colors in pigment or three primary colors in light from an image, the apparatus comprising:

a color separating unit that separates the specific color by correcting a tone level of the specific color and tone levels of two colors based on the tone levels of the two colors, the two colors being two primary colors other than the specific color in pigment when the specific color is one out of three primary colors in pigment and the two colors being two primary colors other than the specific color in light when the specific color is one out of three primary colors in light; and

an area detecting unit that detects the area by specifying the mark based on the corrected tone level of the specific color separated by the color separating unit, wherein

a minimum value of the tone level corresponds to a value of a tone level of a darkest color, and a maximum value of the tone level corresponds to a value of a tone level of a brightest color, and

the color separating unit separates the specific color by adding a value obtained by subtracting a smaller value of a tone level out of tone levels of complementary colors of the two colors from the maximum value of the tone level, to a tone level of a complementary color of the specific color.

3. The apparatus according to claim 1, wherein

the specific color is yellow,

the complementary color of the specific color is blue, and

the complementary colors of the two colors are red and green.

2. An apparatus that detects an area specified based on a mark of a specific color out of three primary colors in pigment or three primary colors in light from an image, the apparatus comprising:

a color separating unit that separates the specific color by correcting a tone level of the specific color and tone levels of two colors based on the tone levels of the two colors, the two colors being two primary colors other than the specific color in pigment when the specific color is one out of three primary colors in pigment and the two colors being two primary colors other than the specific color in light when the specific color is one out of three primary colors in light; and

an area detecting unit that detects the area by specifying the mark based on the corrected tone level of the specific color separated by the color separating unit, wherein

a minimum value of the tone level corresponds to a value of a tone level of a darkest color, and a maximum value of the tone level corresponds to a value of a tone level of a brightest color, and

the color separating unit separates the specific color by adding a value obtained by subtracting a smaller value of a tone level out of tone levels of complementary colors of the two colors multiplied by a predetermined coefficient from the maximum value of the tone level, to a tone level of a complementary color of the specific color.

4. The apparatus according to claim 2, wherein

the specific color is yellow,

the complementary color of the specific color is blue, and

the complementary colors of the two colors are red and green.

5. An apparatus that detects an area specified based on a mark of a specific color out of three primary colors in pigment or three primary colors in light from an image, the apparatus comprising:

a color separating unit that separates the specific color by correcting a tone level of the specific color and tone levels of two colors based on the tone levels of the two colors, the two colors being two primary colors other than the specific color in pigment when the specific color is one out of three primary colors in pigment and the two colors being two primary colors other than the specific color in light when the specific color is one out of three primary colors in light; and

an area detecting unit that detects the area by specifying the mark based on the corrected tone level of the specific color separated by the color separating unit, wherein

a minimum value of the tone level corresponds to a value of a tone level of a darkest color, and a maximum value of the tone level corresponds to a value of a tone level of a brightest color, and

the color separating unit separates the specific color by subtracting a larger value of a tone level out of tone levels of the two colors from the tone level of the specific color.

7. The image-area detecting apparatus according to claim 5, wherein

the specific color is yellow, and

the two colors are cyan and magenta.

6. An apparatus that detects an area specified based on a mark of a specific color out of three primary colors in pigment or three primary colors in light from an image, the apparatus comprising:

a color separating unit that separates the specific color by correcting a tone level of the specific color and tone levels of two colors based on the tone levels of the two colors, the two colors being two primary colors other than the specific color in pigment when the specific color is one out of three primary colors in pigment and the two colors being two primary colors other than the specific color in light when the specific color is one out of three primary colors in light; and

an area detecting unit that detects the area by specifying the mark based on the corrected tone level of the specific color separated by the color separating unit, wherein

a minimum value of the tone level corresponds to a value of a tone level of a darkest color, and a maximum value of the tone level corresponds to a value of a tone level of a brightest color, and

the color separating unit separates the specific color by subtracting a value obtained by multiplying a larger value of a tone level out of tone levels of the two colors by a predetermined coefficient from the tone level of the specific color.

8. The image-area detecting apparatus according to claim 6, wherein

the specific color is yellow, and

the two colors are cyan and magenta.

9. An apparatus that detects an area specified based on a mark of a specific color out of three primary colors in pigment or three primary colors in light from an image, the apparatus comprising:

a color separating unit that separates the specific color by correcting a tone level of the specific color and tone levels of two colors based on the tone levels of the two colors, the two colors being two primary colors other than the specific color in pigment when the specific color is one out of three primary colors in pigment and the two colors being two primary colors other than the specific color in light when the specific color is one out of three primary colors in light; and

an area detecting unit that detects the area by specifying the mark based on the corrected tone level of the specific color separated by the color separating unit, wherein

a minimum value of the tone level corresponds to a value of a tone level of a brightest color, and a maximum value of the tone level corresponds to a value of a tone level of a darkest color, and

the color separating unit separates the specific color by subtracting a larger value of a tone level out of tone levels of complementary colors of the two colors from a tone level of a complementary color of the specific color.

10. A method of detecting an area specified based on a mark of a specific color out of three primary colors in pigment or three primary colors in light from an image, the method comprising:

separating, using a computer, the specific color by correcting the tone level of the specific color and tone levels of two colors based on the tone levels of the two colors, the two colors being two primary colors other than the specific color in pigment when the specific color is one out of three primary colors in pigment and the two colors being two primary colors other than the specific color in light when the specific color is one out of three primary colors in light; and

detecting the area by specifying the mark based on the corrected tone level of the specific color separated at the separating, wherein

a minimum value of the tone level corresponds to a value of a tone level of a darkest color, and a maximum value of the tone level corresponds to a value of a tone level of a brightest color, and

the separating separates the specific color by adding a value obtained by subtracting a smaller value of a tone level out of tone levels of complementary colors of the two colors from the maximum value of the tone level, to a tone level of a complementary color of the specific color.

11. A non-transitory computer-readable recording medium that stores a computer program for detecting an area specified based on a mark of a specific color out of three primary colors in pigment or three primary colors in light from an image, wherein the computer program causes a computer to execute operations, the computer program causing the computer to perform operations comprising:

separating the specific color by correcting the tone level of the specific color and tone levels of two colors based on the tone levels of the two colors, the two colors being two primary colors other than the specific color in pigment when the specific color is one out of three primary colors in pigment and the two colors being two primary colors other than the specific color in light when the specific color is one out of three primary colors in light; and

detecting the area by specifying the mark based on the corrected tone level of the specific color separated at the separating, wherein

a minimum value of the tone level corresponds to a value of a tone level of a darkest color, and a maximum value of the tone level corresponds to a value of a tone level of a brightest color, and

the separating separates the specific color by adding a value obtained by subtracting a smaller value of a tone level out of tone levels of complementary colors of the two colors from the maximum value of the tone level, to a tone level of a complementary color of the specific color.

12. A method of detecting an area specified based on a mark of a specific color out of three primary colors in pigment or three primary colors in light from an image, the method comprising:

separating, using a computer, the specific color by correcting the tone level of the specific color and tone levels of two colors based on the tone levels of the two colors, the two colors being two primary colors other than the specific color in pigment when the specific color is one out of three primary colors in pigment and the two colors being two primary colors other than the specific color in light when the specific color is one out of three primary colors in light; and

detecting the area by specifying the mark based on the corrected tone level of the specific color separated at the separating, wherein

a minimum value of the tone level corresponds to a value of a tone level of a darkest color, and a maximum value of the tone level corresponds to a value of a tone level of a brightest color, and

the separating separates the specific color by subtracting a larger value of a tone level out of tone levels of the two colors from the tone level of the specific color.

13. A non-transitory computer-readable recording medium that stores a computer program for detecting an area specified based on a mark of a specific color out of three primary colors in pigment or three primary colors in light from an image, wherein the computer program causes a computer to execute operations, the computer program causing the computer to perform operations comprising:

separating the specific color by correcting the tone level of the specific color and tone levels of two colors based on the tone levels of the two colors, the two colors being two primary colors other than the specific color in pigment when the specific color is one out of three primary colors in pigment and the two colors being two primary colors other than the specific color in light when the specific color is one out of three primary colors in light; and

detecting the area by specifying the mark based on the corrected tone level of the specific color separated at the separating, wherein a minimum value of the tone level corresponds to a value of a tone level of a darkest color, and a maximum value of the tone level corresponds to a value of a tone level of a brightest color, and

the separating separates the specific color by subtracting a larger value of a tone level out of tone levels of the two colors from the tone level of the specific color.