Image processing apparatus, image processing method, and recording medium with image processing program to process image according to input image

• US 6,628,833 B1
• Filed: 06/23/2000
• Issued: 09/30/2003
• Est. Priority Date: 06/30/1999
• Status: Expired due to Term

• Current Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Original Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Inventors: Horie, Daisaku
• Primary Examiner(s): Tran, Phuoc
• Application Number:
  US09/599,509
• Time in Patent Office: 1,194 Days
• Field of Search: 382/173, 382/195, 382/176, 382/199, 382/162, 382/272, 382/274, 382/286, 358/462, 358/464, 358/465
• US Class Current: 382/173
• CPC Class Codes: G06T 2207/20192 Edge enhancement; Edge preservation
• CPC Class Codes: G06T 5/00 Image enhancement or restoration
• CPC Class Codes: H04N 1/40062 Discrimination between different image types, e.g. two-tone, continuous tone
• CPC Class Codes: H04N 1/403 Discrimination between the two tones in the picture signal of a two-tone original
• CPC Class Codes: H04N 1/4074 using histograms

Abstract

An image processing apparatus includes a reception unit receiving image data, a region determination unit to extract a text region from the received image data, a threshold value calculation unit to calculate the background amount of the extracted text region, and an image correction unit to correct a non-text region of the image data according to the calculated background amount. Since the non-text region of the image data is corrected according to the background amount of the text region, an appropriate correction process can be applied on the image data according to difference in the paper sheet quality and image pickup condition.

Claims

1. An image processing apparatus comprising:

a reception unit receiving image data,

an extraction unit to extract a first region from said received image data,

a calculation unit to calculate a background amount of said extracted first region, and

a correction unit to correct a second region of said image data according to said calculated background amount.

2. The image processing apparatus according to claim 1, wherein said correction unit corrects image data included in said second region so as to remove an amount corresponding to said calculated amount from an image of said second region.

3. The image processing apparatus according to claim 1, wherein said calculation unit calculates a background amount of an area in said first region located close to said second region.

4. The image processing apparatus according to claim 1, wherein said calculation unit calculates a background amount according to standard deviation or average of image data corresponding to the background of said second region.

5. The image processing apparatus according to claim 1, wherein said first region includes a text image region.

6. The image processing apparatus according to claim 5, wherein said second region includes a photograph image region.

7. The image processing apparatus according to claim 5, wherein said second region includes a line copy image region.

8. The image processing apparatus according to claim 1, wherein said correction unit comprises

a threshold value calculation unit to calculate a threshold value according to said calculated background amount, and

an edge detection unit obtaining an edge of the second region in said received image data according to said calculated threshold value.

9. The image processing apparatus according to claim 8, wherein said first region includes a text image region, and said second region includes a line copy image region.

10. The image processing apparatus according to claim 1, wherein said correction unit includes a threshold value calculation unit calculating a threshold of color distance according to said calculated background amount, and

a subtractive color processing unit subtracting color of said second region in said received image data according to said calculated threshold value of color distance.

11. The image processing apparatus according to claim 10, wherein said first region includes a text image region, and said second region includes a line copy image region.

12. An image processing method comprising the steps of:

receiving image data,

extracting a first region from said received image data,

calculating a background amount of said extracted first region, and

correcting a second region of said image data according to said calculated background amount.

13. A computer-readable recording medium recorded with an image processing program for a computer to execute the steps of:

receiving image data,

extracting a first region from said received image data,

calculating a background amount of said extracted first region, and

correcting a second region of said image data according to said calculated background amount.