CN108447030A - A kind of image processing method of descreening - Google Patents
A kind of image processing method of descreening Download PDFInfo
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- CN108447030A CN108447030A CN201810167029.7A CN201810167029A CN108447030A CN 108447030 A CN108447030 A CN 108447030A CN 201810167029 A CN201810167029 A CN 201810167029A CN 108447030 A CN108447030 A CN 108447030A
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- reticulate pattern
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- 238000003672 processing method Methods 0.000 title claims abstract description 10
- 238000006243 chemical reaction Methods 0.000 claims abstract description 13
- 230000003044 adaptive effect Effects 0.000 claims abstract description 4
- 238000003708 edge detection Methods 0.000 claims description 8
- 238000013075 data extraction Methods 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 3
- 238000007781 pre-processing Methods 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 8
- 239000000463 material Substances 0.000 abstract description 2
- 230000000007 visual effect Effects 0.000 abstract description 2
- 230000000694 effects Effects 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
Classifications
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T5/00—Image enhancement or restoration
- G06T5/73—Deblurring; Sharpening
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/10—Segmentation; Edge detection
- G06T7/13—Edge detection
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/10—Image acquisition modality
- G06T2207/10004—Still image; Photographic image
- G06T2207/10008—Still image; Photographic image from scanner, fax or copier
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/20—Special algorithmic details
- G06T2207/20024—Filtering details
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Image Processing (AREA)
- Facsimile Image Signal Circuits (AREA)
Abstract
The present invention provides a kind of image processing method of descreening, it would be desirable to which the picture of processing carries out capture acquisition, obtains the picture height X and picture width Y of pending picture, and as unit of pixel, the picture size for obtaining pending picture is x × y；Pending picture is subjected to double format conversions again；Picture size after progress double format conversions is pre-processed, then sorted out according to the type of picture, establish coordinate system, the radius that this method passes through the kernel function of adaptive adjustment filter, scale size and direction, obtained filter is changed according to picture material, adaptively remove the reticulate pattern in scan image, the clarity at edge in image is protected simultaneously, the present invention is while effectively removing halftoning reticulate pattern, sharp-edged continuous-tone image is obtained, effectively increase scan image quality, improve the visual effect of scan image, the problems such as capable of solving scan image display on an electronic device and reprinting.
Description
Technical field
The present invention is a kind of image processing method of descreening, belongs to image technique process field.
Background technology
In the prior art, electronic image printer generally prints continuous-tone image using halftoning technique, even
Continuous tone images are converted into digital halftone image and print on paper.However if paper document to printing in this way
Image is scanned, and the halftoning reticulate pattern as screen window will appear in obtained scan image, causes very poor regard
Feel effect.These images generate moire effect when printing again, reduce print quality.
Existing anti-halftoning algorithm is not suitable for scanning half tone image, and scanning half-tone picture seems gray level image, and
These algorithms can only handle two-value half tone image.Some algorithms also need to know that half tone image generates the details letter in algorithm
Breath, so needing a kind of new method to solve the above problems.
Invention content
In view of the deficienciess of the prior art, it is an object of the present invention to provide a kind of image processing method of descreening, with solution
Certainly the problems mentioned above in the background art, the present invention is easy to use, and easy to operation, stability is good, and reliability is high.
To achieve the goals above, the present invention is to realize by the following technical solutions：At a kind of picture of descreening
Reason method, includes the following steps：
S1, image preprocessing：Picture to be treated is subjected to capture acquisition, obtains the picture height X and figure of pending picture
Piece width Y, as unit of pixel, the picture size for obtaining pending picture is x × y；Pending picture is carried out again
Double format conversions；Picture size after progress double format conversions is pre-processed, then according to the type of picture
Sorted out, establish coordinate system, positions prime area；
S2, data extraction：Picture is traversed, the R of picture pixels point, G are captured, channel B pixel value utilizes all pixels point
R, G, channel B pixel value carries out edge detection and solves the gradient difference of each pixel, and contour area is obtained using edge detection；
Reticulate pattern edge extracting is carried out using the gradient difference of each pixel simultaneously, obtains reticulate pattern fringe region；
S3, data processing：Using based on redundancy Denoising Algorithm in image, the random noise in scan image is removed；Using
Discrete cosine transform to carry out frequency-domain transform to the scan image after denoising, detects and extract the reticulate pattern frequency of halftone pattern；
Using the scan image after denoising as input, Steerable filter is carried out to it to obtain the Grad of each pixel；By above-mentioned mistake
The reticulate pattern frequency of the halftone pattern obtained in journey and the Grad of scan image construct sef-adapting filter, use adaptive-filtering
Device is filtered scan image, obtains estimating image substantially；With scan image and basic estimation image obtained above
It as input, is filtered using holding edge filter algorithm, obtains the continuous tone figure after removal halftone pattern.
Further, the kernel function of the sef-adapting filter selects two-dimensional Gaussian kernel, and core coefficient is by reticulate pattern frequency and ladder
Information self-adapting is spent to determine.
Further, to carrying out size adjusting by double format conversions, the height of picture is 200,66 or 118, right
The picture width answered is 158,72 or 84.
Beneficial effects of the present invention：A kind of image processing method of descreening of the present invention, this method passes through adaptive
Adjust filter kernel function radius, scale size and direction so that obtained filter can according to picture material into
Row variation adaptively removes the reticulate pattern in scan image, while the clarity at edge in image, the present invention being protected to be gone effectively
While except halftoning reticulate pattern, sharp-edged continuous-tone image has been obtained, has effectively increased scan image quality, improvement is swept
The visual effect of picture of tracing designs has extremely important the problems such as capable of solving scan image display on an electronic device and reprint
Practical application valence.
Specific implementation mode
To make the technical means, the creative features, the aims and the efficiencies achieved by the present invention be easy to understand, with reference to
Specific implementation mode, the present invention is further explained.
The present invention provides a kind of technical solution：A kind of image processing method of descreening, includes the following steps：
S1, image preprocessing：Picture to be treated is subjected to capture acquisition, obtains the picture height X and figure of pending picture
Piece width Y, as unit of pixel, the picture size for obtaining pending picture is x × y；Pending picture is carried out again
Double format conversions；Picture size after progress double format conversions is pre-processed, then according to the type of picture
Sorted out, establish coordinate system, positions prime area；
S2, data extraction：Picture is traversed, the R of picture pixels point, G are captured, channel B pixel value utilizes all pixels point
R, G, channel B pixel value carries out edge detection and solves the gradient difference of each pixel, and contour area is obtained using edge detection；
Reticulate pattern edge extracting is carried out using the gradient difference of each pixel simultaneously, obtains reticulate pattern fringe region；
S3, data processing：Using based on redundancy Denoising Algorithm in image, the random noise in scan image is removed；Using
Discrete cosine transform to carry out frequency-domain transform to the scan image after denoising, detects and extract the reticulate pattern frequency of halftone pattern；
Using the scan image after denoising as input, Steerable filter is carried out to it to obtain the Grad of each pixel；By above-mentioned mistake
The reticulate pattern frequency of the halftone pattern obtained in journey and the Grad of scan image construct sef-adapting filter, use adaptive-filtering
Device is filtered scan image, obtains estimating image substantially；With scan image and basic estimation image obtained above
It as input, is filtered using holding edge filter algorithm, obtains the continuous tone figure after removal halftone pattern.
The kernel function of the sef-adapting filter selects two-dimensional Gaussian kernel, core coefficient adaptive by reticulate pattern frequency and gradient information
It should determine, to carrying out size adjusting by double format conversions, the height of picture is 200,66 or 118, and corresponding picture is wide
Degree is 158,72 or 84.
Embodiment 1：Picture to be treated is subjected to capture acquisition, obtains the picture height X and picture of pending picture
Width Y, as unit of pixel, the picture size for obtaining pending picture is x × y；Pending picture is subjected to double again
Format conversion；Picture size after progress double format conversions is pre-processed, is then returned according to the type of picture
Class establishes coordinate system, positions prime area, data extraction：Picture is traversed, the R of picture pixels point, G, channel B are captured
Pixel value, using the R of all pixels point, G, channel B pixel value carries out the gradient difference that edge detection solves each pixel, utilizes
Edge detection obtains contour area；Reticulate pattern edge extracting is carried out using the gradient difference of each pixel simultaneously, obtains reticulate pattern edge
Region, data processing：Using based on redundancy Denoising Algorithm in image, the random noise in scan image is removed；Using from
Scattered cosine transform to carry out frequency-domain transform to the scan image after denoising, detects and extract the reticulate pattern frequency of halftone pattern；It will
Scan image after denoising carries out it Steerable filter to obtain the Grad of each pixel as input；By the above process
In the obtained Grad construction sef-adapting filter of the reticulate pattern frequency of halftone pattern and scan image, use sef-adapting filter
Scan image is filtered, obtains estimating image substantially；Made with scan image and basic estimation image obtained above
It for input, is filtered using holding edge filter algorithm, obtains the continuous tone figure after removal halftone pattern.
The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention, for this field skill
For art personnel, it is clear that invention is not limited to the details of the above exemplary embodiments, and without departing substantially from the present invention spirit or
In the case of essential characteristic, the present invention can be realized in other specific forms.Therefore, in all respects, should all incite somebody to action
Embodiment regards exemplary as, and is non-limiting, the scope of the present invention by appended claims rather than on state
Bright restriction, it is intended that including all changes that come within the meaning and range of equivalency of the claims in the present invention
It is interior.Claim should not be considered as and be limited the claims involved.
In addition, it should be understood that although this specification is described in terms of embodiments, but not each embodiment is only wrapped
Containing an independent technical solution, this description of the specification is merely for the sake of clarity, and those skilled in the art should
It considers the specification as a whole, the technical solutions in the various embodiments may also be suitably combined, forms those skilled in the art
The other embodiment being appreciated that.
Claims (3)
1. a kind of image processing method of descreening, it is characterised in that include the following steps：
S1, image preprocessing：Picture to be treated is subjected to capture acquisition, obtains the picture height X and figure of pending picture
Piece width Y, as unit of pixel, the picture size for obtaining pending picture is x × y；Pending picture is carried out again
Double format conversions；Picture size after progress double format conversions is pre-processed, then according to the type of picture
Sorted out, establish coordinate system, positions prime area；
S2, data extraction：Picture is traversed, the R of picture pixels point, G are captured, channel B pixel value utilizes all pixels point
R, G, channel B pixel value carries out edge detection and solves the gradient difference of each pixel, and contour area is obtained using edge detection；
Reticulate pattern edge extracting is carried out using the gradient difference of each pixel simultaneously, obtains reticulate pattern fringe region；
S3, data processing：Using based on redundancy Denoising Algorithm in image, the random noise in scan image is removed；Using
Discrete cosine transform to carry out frequency-domain transform to the scan image after denoising, detects and extract the reticulate pattern frequency of halftone pattern；
Using the scan image after denoising as input, Steerable filter is carried out to it to obtain the Grad of each pixel；By above-mentioned mistake
The reticulate pattern frequency of the halftone pattern obtained in journey and the Grad of scan image construct sef-adapting filter, use adaptive-filtering
Device is filtered scan image, obtains estimating image substantially；With scan image and basic estimation image obtained above
It as input, is filtered using holding edge filter algorithm, obtains the continuous tone figure after removal halftone pattern.
2. a kind of image processing method of descreening according to claim 1, it is characterised in that：The sef-adapting filter
Kernel function select two-dimensional Gaussian kernel, core coefficient is by reticulate pattern frequency and gradient information adaptive determining.
3. a kind of image processing method of descreening according to claim 1, it is characterised in that：To passing through double formats
Conversion carries out size adjusting, and the height of picture is 200,66 or 118, and corresponding picture width is 158,72 or 84.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810167029.7A CN108447030A (en) | 2018-02-28 | 2018-02-28 | A kind of image processing method of descreening |
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| CN201810167029.7A CN108447030A (en) | 2018-02-28 | 2018-02-28 | A kind of image processing method of descreening |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112562020A (en) * | 2020-12-23 | 2021-03-26 | 绍兴图信物联科技有限公司 | TIFF image and halftone image format conversion method based on least square method |
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| CN101552860A (en) * | 2009-05-13 | 2009-10-07 | 西安理工大学 | De-screening method of halftone image based on dot detection and dot padding |
| CN102019771A (en) * | 2009-09-11 | 2011-04-20 | 富士施乐株式会社 | Image processing apparatus, system and method |
| CN103561194A (en) * | 2013-09-16 | 2014-02-05 | 湖南大学 | Scanned image descreening method based on adaptive filtering |
| CN107016657A (en) * | 2017-04-07 | 2017-08-04 | 河北工业大学 | The restorative procedure of the face picture covered by reticulate pattern |
| CN107358582A (en) * | 2017-06-19 | 2017-11-17 | 西安理工大学 | The printing image of adaptively selected gaussian filtering parameter removes network method |
| US20180013922A1 (en) * | 2015-01-14 | 2018-01-11 | Samsung Electronics Company., Ltd. | Frequency-adaptive descreening method and device for performing same |
-
2018
- 2018-02-28 CN CN201810167029.7A patent/CN108447030A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101552860A (en) * | 2009-05-13 | 2009-10-07 | 西安理工大学 | De-screening method of halftone image based on dot detection and dot padding |
| CN102019771A (en) * | 2009-09-11 | 2011-04-20 | 富士施乐株式会社 | Image processing apparatus, system and method |
| CN103561194A (en) * | 2013-09-16 | 2014-02-05 | 湖南大学 | Scanned image descreening method based on adaptive filtering |
| US20180013922A1 (en) * | 2015-01-14 | 2018-01-11 | Samsung Electronics Company., Ltd. | Frequency-adaptive descreening method and device for performing same |
| CN107016657A (en) * | 2017-04-07 | 2017-08-04 | 河北工业大学 | The restorative procedure of the face picture covered by reticulate pattern |
| CN107358582A (en) * | 2017-06-19 | 2017-11-17 | 西安理工大学 | The printing image of adaptively selected gaussian filtering parameter removes network method |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112562020A (en) * | 2020-12-23 | 2021-03-26 | 绍兴图信物联科技有限公司 | TIFF image and halftone image format conversion method based on least square method |
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