Image processing apparatus

• US 6,198,844 B1
• Filed: 01/27/1999
• Issued: 03/06/2001
• Est. Priority Date: 01/28/1998
• Status: Expired due to Fees

• Current Assignee: Konica Corporation (Konica Minolta Inc.)
• Original Assignee: Konica Corporation (Konica Minolta Inc.)
• Inventors: Nomura, Shouichi
• Primary Examiner(s): Tran, Phuoc
• Application Number:
  US09/237,967
• Time in Patent Office: 769 Days
• Field of Search: 382/168, 382/169, 382/167, 382/171, 382/274, 382/260, 358/518, 358/522, 358/521
• US Class Current: 382/168
• CPC Class Codes: H04N 1/4074 using histograms

Abstract

A method of processing an image includes steps of: obtaining data concerning the brightness of an original image; dividing the data concerning the brightness into a plurality of groups for each brightness domain on the basis of the histogram of the data concerning the brightness; preparing correction information for correcting the data concerning the brightness for each of the plurality of groups, and executing image processing to the original image on the basis of the correction information.

Claims

1. A method of processing an image, comprising steps of:

obtaining data concerning the brightness of an original image;

dividing the data concerning the brightness into a plurality of groups for each brightness domain on the basis of the histogram of the data concerning the brightness;

preparing correction information for correcting the data concerning the brightness for each of the plurality of groups, and

executing image processing to the original image on the basis of the correction information.

2. The method of claim 1, wherein the preparing step comprises:

producing a mask to correct the data concerning the brightness for each of the plurality of groups; and

blurring the mask by using a blurring filter so as to prepare the correction information.

3. The method of claim 2, wherein the executing step executes the image processing by adding the original image with the correction information for each pixel.

4. The method of claim 1, wherein the preparing step prepares the correction information such that each brightness having the highest frequency in each group comes relatively close to each other.

5. The method of claim 2, wherein the producing step produces the mask such that each brightness having the highest frequency in each group comes relatively close to each other and the data in the mask are equal for plural pixels belonging the same group among the plurality of groups.

6. An apparatus for processing an image, comprising:

data obtaining means for obtaining data concerning the brightness of an original image;

dividing means for dividing the data concerning the brightness into a plurality of groups for each brightness domain on the basis of the histogram of the data concerning the brightness;

preparing means for preparing correction information for correcting the data concerning the brightness for each of the plurality of groups, and

executing means for executing image processing to the original image on the basis of the correction information.

7. The apparatus of claim 6, wherein the preparing means comprises:

producing means for producing a mask to correct the data concerning the brightness for each of the plurality of groups; and

blurring means for blurring the mask by using a blurring filter so as to prepare the correction information.

8. The apparatus of claim 7, wherein the executing means executes the image processing by adding the original image with the correction information for each pixel.

9. The apparatus of claim 6, wherein the preparing means prepares the correction information such that each brightness having the highest frequency in each group comes relatively close to each other.

10. The apparatus of claim 7, wherein the producing means produces the mask such that each brightness having the highest frequency in each group comes relatively close to each other and the data in the mask are equal for plural pixels belonging the same group among the plurality of groups.

11. A media in which a program to execute an image processing is stored and from which the program is read by a computer to execute the image processing comprising steps of:

obtaining data concerning the brightness of an original image;

dividing the data concerning the brightness into a plurality of groups for each brightness domain on the basis of the histogram of the data concerning the brightness;

preparing correction information for correcting the data concerning the brightness for each of the plurality of groups, and

executing image processing to the original image on the basis of the correction information.

12. The media of claim 11, wherein the preparing step comprises:

producing a mask to correct the data concerning the brightness for each of the plurality of groups; and

blurring the mask by using a blurring filter so as to prepare the correction information.

13. The media of claim 12, wherein the executing step executes the image processing by adding the original image with the correction information for each pixel.

14. The media of claim 11, wherein the preparing step prepares the correction information such that each brightness having the highest frequency in each group comes relatively close to each other.

15. The media of claim 12, wherein the producing step produces the mask such that each brightness having the highest frequency in each group comes relatively close to each other and the data in the mask are equal for plural pixels belonging the same group among the plurality of groups.