Image processing device and recording medium

• US 6,901,170 B1
• Filed: 09/05/2000
• Issued: 05/31/2005
• Est. Priority Date: 09/05/2000
• Status: Expired due to Term

• Current Assignee: Fujifilm Business Innovation Corp. (Fujifilm Holdings Corporation), GTX Corp.
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Terada, Yoshihiro, Ling, Marvin T., Filipski, Alan
• Primary Examiner(s): LEE, TOMMY D
• Application Number:
  US09/655,310
• Time in Patent Office: 1,729 Days
• Field of Search: 382/254, 382/260, 382/262, 382/264, 382/266, 382/269, 382/261
• US Class Current: 382/260
• CPC Class Codes: G06T 2207/10008 from scanner, fax or copier
• CPC Class Codes: G06T 2207/20012 Locally adaptive
• CPC Class Codes: G06T 2207/20016 Hierarchical, coarse-to-fine, multiscale or multiresolution image processing; Pyramid transform
• CPC Class Codes: G06T 2207/20192 Edge enhancement; Edge preservation
• CPC Class Codes: G06T 2207/30176 Document
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/174 involving the use of two or more images

Abstract

An image processing apparatus and a recording medium which can improve the quality of a color document image. Smoothing conditions which are defined by three parameters of “filter size”, “offset”, and “overlap” are set. An edge image which was generated in an edge detection processing is referred to, and a determination is made as to whether an edge pixel exists in a noticed region. When the edge pixel does not exist in the noticed region, a smoothing processing is carried out. When the edge pixel exists in the noticed region, it is determined inappropriate to effect the smoothing processing, and the process goes to a subsequent processing without effecting the smoothing processing. The processing is carried out until the image scanning ends. When the image scanning ends, the next smoothing conditions are set and the processing which is the same as the one described above is performed.

Claims

1. An image processing apparatus, comprising:

edge detection unit that detects an edge from an input image, the input image having been read by an image reading unit that scan-reads an image; and

smoothing unit that carries out a plurality of smoothing processings, and in the smoothing processing, said smoothing unit selects one smoothing condition from a plurality of smoothing conditions, which have been determined in advance and which include a region to be processed which is smaller than the input image, an amount of movement of the region to be processed, and a range of scanning in the input image, and on the basis of the selected smoothing condition, said smoothing unit smoothes an interior of the region to be processed in the input image, in which the edge is not detected, while moving and scanning the region to be processed within the range of scanning by the amount of movement.

2. An image processing apparatus according to claim 1, further comprising:

storing unit that stores the plurality of smoothing conditions which have been determined in advance.

3. An image processing apparatus according to claim 1, wherein said smoothing unit obtains a mean value of pixel values in the region to be processed, and said smoothing unit smoothes the interior of the region to be processed by replacing the pixel values in the region to be processed with the obtained mean value.

4. An image processing apparatus according to claim 1, wherein said smoothing unit obtains a central value of the pixel values in the region to be processed, and said smoothing unit smoothes the interior of the region to be processed by replacing the pixel values in the region to be processed with the obtained central value.

5. An image processing apparatus according to claim 1, wherein said smoothing unit determines whether the detected edge exists in the region to be processed, and if the edge does not exist, said smoothing unit extends the region to be processed.

6. An image processing apparatus according to claim 5, wherein said smoothing unit determines whether the detected edge exists in the region to be processed, and if the edge is non-existent, said smoothing unit repeats a processing for extending the region to be processed until it is determined that the edge exists, and when the edge exists in the extended region to be processed, said smoothing unit resets the last region to be processed as a region to be processed.

7. An image processing apparatus according to claim 5, wherein a size of the region to be processed is variable.

8. An image processing apparatus according to claim 1, further comprising:

image generating unit that which generates a plurality of converted images having resolutions which are lower than the resolution of the input image,

wherein said smoothing unit further generates a plurality of smoothed images by carrying out the plurality of smoothing processings on the plurality of converted images, and said smoothing unit respectively converts the plurality of generated smoothed images into converted smoothed images whose resolutions are the same as the resolution of the input image, and said smoothing unit synthesizes the input image and the converted smoothed images which have been respectively converted.

9. An image processing apparatus according to claim 1, further comprising:

segment element extracting unit that extracts a segment element from the input image; and

difference image generating unit that generates a difference image in which the segment element is excluded from the input image,

wherein said smoothing unit carries out the plurality of smoothing processings on the difference image.

10. An image processing apparatus according to claim 9, wherein a pixel value of a pixel included in the segment element is compared to a pixel value of a specific color which has been determined in advance,

and if the difference between the pixel value of the pixel included in the segment element and the pixel value of the specific color which has been determined in advance falls within a predetermined range, the pixel value of the pixel included in the segment element is replaced with the pixel value of the specific color.

11. An image processing apparatus according to claim 10, wherein the specific color is black.

12. An image processing apparatus according to claim 1, wherein the smoothing unit carries out the plurality of smoothing processings from a region to be processed with a larger size.

13. An image processing apparatus according to claim 1, wherein the input image comprises a document image which can include character information, a graph and a diagram.

14. A computer readable recording medium on which a program for executing processings is recorded, said program comprising:

detecting an edge from an input image which has been read by an image reading unit that scan-reads an image; and

carrying out a plurality of smoothing processings, and in the smoothing processing, a smoothing condition is selected from a plurality of smoothing conditions, which have been determined in advance and which include a region to be processed which is smaller than the input image, an amount of movement of the region to be processed, and a range of scanning in the input image, and on the basis of the selected smoothing condition, smoothing an interior of the region to be processed in the input image, in which the edge is not detected, while moving and scanning the region to be processed within the range of scanning by the amount of movement.

15. An image processing apparatus, comprising:

an edge detection unit that detects an edge from an input image, the input image having been read by an image reading unit that scan-reads an image; and

smoothing unit that carries out a plurality of smoothing processings, and in the smoothing processing, said smoothing unit selects one smoothing condition from a plurality of smoothing conditions, which have been determined in advance and which include a region to be processed which is smaller than the input image, an amount of movement of the region to be processed, and a range of scanning in the input image, and on the basis of the selected smoothing condition, said smoothing unit smoothes an interior of the region to be processed in the input image, in which the edge is not detected, while moving and scanning the region to be processed within the range of scanning by the amount of movement,

wherein each of the plurality of smoothing conditions includes,

a filter size parameter for indicating a size of the region to be processed,

an overlap parameter for indicating a width of an overlapped region of the region to be processed and a region to be processed after movement by the amount of movement, and

an offset parameter for indicating a distance from an end portion of the input image to an end portion of the range of scanning.

16. A computer readable recording medium on which a program for executing processings is recorded, said program comprising:

detecting an edge from an input image which has been read by an image reading unit that scan-reads an image; and

carrying out a plurality of smoothing processings, and in the smoothing processing, a smoothing condition is selected from a plurality of smoothing conditions, which have been determined in advance and which include a region to be processed which is smaller than the input image, an amount of movement of the region to be processed, and a range of scanning in the input image, and on the basis of the selected smoothing condition, smoothing an interior of the region to be processed in the input image, in which the edge is not detected, while moving and scanning the region to be processed within the range of scanning by the amount of movement,

wherein each of the plurality of smoothing conditions includes,

a filter size parameter for indicating a size of the region to be processed,

an overlap parameter for indicating a width of an overlapped region of the region to be processed and a region to be processed after movement by the amount of movement, and

an offset parameter for indicating a distance from an end portion of the input image to an end portion of the range of scanning.