Image-processing method, image-processing device, and storage medium

• US 6,954,288 B2
• Filed: 12/22/2000
• Issued: 10/11/2005
• Est. Priority Date: 12/27/1999
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamazoe, Manabu, Uekusa, Akihiko
• Primary Examiner(s): Williams, Kimberly
• Assistant Examiner(s): BURLESON, MICHAEL L
• Application Number:
  US09/742,122
• Publication Number:
  US 20010013953A1
• Time in Patent Office: 1,754 Days
• Field of Search: 358/1.9, 358/2.1, 358/519, 358/518, 382/162, 382/170
• US Class Current: 358/1.9
• CPC Class Codes: H04N 1/6027 Correction or control of colour gradation or colour contrast H04N1/6058 takes precedence
• CPC Class Codes: H04N 1/603 controlled by characteristics of the picture signal generator or the picture reproducer
• CPC Class Codes: H04N 1/6072 adapting to different types of images, e.g. characters, graphs, black and white image portions

Abstract

An image-processing method for performing color matching using a source profile and an output profile, includes a step of correcting input image data, a step of calculating a feature quantity of an input image based on the corrected image data, a step of performing an image correction process on the input image data in accordance with a processing condition responsive to the feature quantity, and a step of performing a color matching process on the corrected input image data. The image-processing method is thus performed with the color matching process result taken into account.

Claims

1. An image-processing method for performing color matching using a source profile and an output profile, said method comprising the steps of:

determining the type of input image, based on a rendering command indicating the input image;

correcting input image data in accordance with the source profile when it is determined in said determining step that the input image is a photograph image;

calculating a feature quantity of the input image based on the corrected input image data;

performing an image correction process on the corrected input image data in accordance with a processing condition responsive to the feature quantity; and

performing a color matching process on the input image data when it is determined in said determining step that the input image is not a photograph image, and on the corrected input image data subjected to the image correction process when it is determined in said determining step that the input image is a photograph image.

2. An image-processing method according to claim 1, wherein the correction of the input image data in accordance with the source profile is based on a gamma value described in the source profile.

3. An image-processing method according to claim 1, wherein the correction of the input image data in accordance with the source profile is based on a white point described in the source profile.

4. An image-processing method according to claim 1, wherein the color matching process is performed according to the type of the input image.

5. An image-processing method for performing color matching using a source profile and an output profile, said method comprising the steps of:

determining the type of input image based on a rendering command indicating the input image;

correcting input image data in accordance with the source profile when it is determined in said determining step that the input image is a photograph image;

calculating a feature quantity of the input image based on the corrected input image data;

performing an image correction process on the corrected input image data in accordance with a processing condition responsive to the feature quantity; and

performing a color matching process on the input image data when it is determined in said determining step that the input image is not a photograph image, and on the corrected input image data subjected to the image correction process when it is determined in said determining step that the input image is a photograph image,

wherein said calculation step includes a substep of creating a histogram based on the corrected input image data, and a substep of calculating a high-light point and a shadow point.

6. An image-processing device for performing color matching using a source profile and an output profile, said device comprising:

determination means for determining the type of input image, based on a rendering command indicating the input image;

correction means for correcting input image data in accordance with the source profile when it is determined by said determination means that the input image data is a photograph image;

calculation means for calculating a feature quantity of the input image based on the corrected input image data;

image correction processor means for performing an image correction process on the corrected input image data in accordance with a processing condition responsive to the feature quantity; and

color matching processor means for performing a color matching process on the input image data when it is determined by said determination means that the input image is not a photograph image, and on the corrected input image data subjected to the image correction process when it is determined by said determination means that the input image is a photograph image.

7. A storage medium for storing a computer-readable software program of an image-processing method for performing color matching using a source profile and an output profile, the software program comprising:

code for a determining step, of determining the type of input image, based on a rendering command indicating the input image;

code for a correction step, of correcting input image data in accordance with the source profile when it is determined by said code for a determining step that the input image is a photograph image;

code for a calculation step, of calculating a feature quantity of the input image based on the input image data;

code for an image correction step, of performing an image correction process on the corrected input image data in accordance with a processing condition responsive to the feature quantity; and

code for a color matching step, of performing a color matching process on the input image data when it is determined by said code for determining step that the input image is not a photograph image, and on the corrected input image data subjected to the image correction process when it is determined by said code for a determining step that the input image is a photograph image.

8. An image-processing apparatus for performing color matching using a source profile and an output profile, said apparatus comprising:

a determination unit adapted to determine the type of input image, based on a rendering command indicating the input image;

a correction unit adapted to correct input image data in accordance with the source profile when it is determined by said determination unit that the input image is a photograph image;

a calculation unit adapted to calculate a feature quantity of the input image based on the corrected input image data;

an image correction processor unit adapted to process an image correction process on the corrected input image data in accordance with a processing condition responsive to the feature quantity; and

a color matching processor adapted to perform a color matching process on the input image data when it is determined by said determination unit that the input image is not a photograph image, and on the corrected input image data subjected to the image correction process when it is determined by said determination unit that the input image is a photograph image,

wherein said calculation unit includes a histogram creation unit adapted to create a histogram based on the corrected input image data, and another calculation unit adapted to calculate a high-light point and a shadow point.

9. A storage medium for storing a computer-readable software program of an image-processing method for performing color matching using a source profile and an output profile, the software program comprising:

code for a determining step, of determining the type of input image, based on a rendering command indicating the input image;

code for a correction step, of correcting input image data in accordance with the source profile when it is determined by said code for a determining step that the input image is a photograph image;

code for a calculation step, of calculating a feature quantity of the input image based on the input image data;

code for an image correction step, of performing an image correction process on the corrected input image data in accordance with a processing condition responsive to the feature quantity; and

code for a color matching step, of performing a color matching process on the input image data when it is determined by said code for determining step that the input image is not a photograph image, and on the corrected input image data subjected to the image correction process when it is determined by said code for a determining step that the input image is a photograph image,

wherein said code for a calculation step includes code for a substep of creating a histogram based on the corrected input image data, and code for a substep of calculating a high-light point and a shadow point.