CN101578855B - digital image enhancement - Google Patents
digital image enhancement Download PDFInfo
- Publication number
- CN101578855B CN101578855B CN200880000107.9A CN200880000107A CN101578855B CN 101578855 B CN101578855 B CN 101578855B CN 200880000107 A CN200880000107 A CN 200880000107A CN 101578855 B CN101578855 B CN 101578855B
- Authority
- CN
- China
- Prior art keywords
- image
- brightness
- adjustment
- adj
- dynamic range
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 claims description 31
- 230000006835 compression Effects 0.000 claims description 8
- 238000007906 compression Methods 0.000 claims description 8
- 239000000284 extract Substances 0.000 abstract 1
- 108090000623 proteins and genes Proteins 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 3
- 238000005728 strengthening Methods 0.000 description 3
- 230000002708 enhancing effect Effects 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- YBJHBAHKTGYVGT-ZKWXMUAHSA-N (+)-Biotin Chemical compound N1C(=O)N[C@@H]2[C@H](CCCCC(=O)O)SC[C@@H]21 YBJHBAHKTGYVGT-ZKWXMUAHSA-N 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000011002 quantification Methods 0.000 description 1
- 238000013139 quantization Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- FEPMHVLSLDOMQC-UHFFFAOYSA-N virginiamycin-S1 Natural products CC1OC(=O)C(C=2C=CC=CC=2)NC(=O)C2CC(=O)CCN2C(=O)C(CC=2C=CC=CC=2)N(C)C(=O)C2CCCN2C(=O)C(CC)NC(=O)C1NC(=O)C1=NC=CC=C1O FEPMHVLSLDOMQC-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
- H04N5/57—Control of contrast or brightness
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T5/00—Image enhancement or restoration
- G06T5/90—Dynamic range modification of images or parts thereof
- G06T5/92—Dynamic range modification of images or parts thereof based on global image properties
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
- H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
- H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
- H04N21/431—Generation of visual interfaces for content selection or interaction; Content or additional data rendering
- H04N21/4318—Generation of visual interfaces for content selection or interaction; Content or additional data rendering by altering the content in the rendering process, e.g. blanking, blurring or masking an image region
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
- H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
- H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
- H04N21/44—Processing of video elementary streams, e.g. splicing a video clip retrieved from local storage with an incoming video stream or rendering scenes according to encoded video stream scene graphs
- H04N21/44008—Processing of video elementary streams, e.g. splicing a video clip retrieved from local storage with an incoming video stream or rendering scenes according to encoded video stream scene graphs involving operations for analysing video streams, e.g. detecting features or characteristics in the video stream
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Image Processing (AREA)
- Facsimile Image Signal Circuits (AREA)
- Picture Signal Circuits (AREA)
Abstract
Strengthen image and comprise its brightness of adjustment, then carry out the setting contrast of brightness adjustment image.Adjustment brightness is the estimation of a use real world brightness.Setting contrast relates to and extracts background and contrast information, merged the contrast information of background and correction based on background information and obtained output image by a Dynamic gene adjustment contrast information.
Description
Technical field
The present invention relates to digital image enhancement (digital image enhancement), particularly strengthen the method for luminance digital image and contrast.
Background of invention
No matter digital picture is static images or video image, is recorded to always all can not to catch under desirable lighting conditions.Natural lighting condition may be often too bright or too secretly, the artificial daylight of camera work outdoor then often provides irregular illumination.Thus cause the image captured to have poor visual quality (visual quality).
In prior art, propose multiple technologies be used for improving or strengthening picture quality.Recently, the many methods strengthening image are disclosed at american documentation literature US 2008/0101719 (inventor Lim etc.), US 2008/0012992 and 2007/0171310 (inventor Arici etc.) and US 2007/0071350 (inventor Lee etc.).Especially, US 2008/0101719 (inventor Lim etc.) has carried out useful discussion to the multiple known technology improving picture quality.All these diverse ways all successfully make moderate progress to picture quality to some extent.
Summary of the invention
There is disclosed herein a kind of digital image enhancement method, be used for adjusting the brightness of input picture to obtain the image of a brightness adjustment, then adjust the contrast of brightness adjustment image to obtain an output image strengthened.
The method comprises:
The brightness of adjustment input picture and obtain the image of a brightness adjustment, comprising: estimate that the real world brightness of input picture, adjustment image are to the brightness estimated and compression adjusts the dynamic range of image,
A low pass filter is used to extract background information from the image of brightness adjustment,
Background information is deleted to extract contrast information from the image of brightness adjustment,
Adjustment contrast information, and
Merge the contrast information after background information and adjustment and obtain output image.
Preferably, the image that brightness strengthens is quantized.
Contrast information adjusts by being multiplied by a setting contrast factor (contrast adjustment factor), and the setting contrast factor is the function of background information.
A kind of digital image enhancement method, the brightness being used for adjusting input picture, to obtain a brightness adjustment image, comprising: estimate that the real world brightness of input picture, adjustment image are to the brightness estimated and compression adjusts the dynamic range of image.
A kind of digital image enhancement method, is used for the contrast of correcting luminance adjustment image, comprising:
A low pass filter is utilized to extract the background information of input picture,
Background information is deleted to extract the contrast information of input picture from input picture,
Adjustment contrast information, and
Merge the contrast information of background information and adjustment to obtain an output image.
Accompanying drawing explanation
Now according to example typical way of the present invention is described with reference to the drawings, wherein:
Fig. 1 is the theory diagram of image enhaucament basic step of the present invention;
Fig. 2 is the theory diagram of the more details of a story of display brightness set-up procedure;
Fig. 3 is the FBD (function block diagram) of brightness adjustment;
Fig. 4 is the theory diagram of the more details of a story of display comparison degree set-up procedure; With
Fig. 5 is the FBD (function block diagram) of setting contrast.
Preferred embodiment describes in detail
Following exemplary embodiments of the present invention provides by means of only example, but this is not be intended to limit the scope of application of the present invention or function.The present invention includes two aspects, i.e. brightness adjustment and setting contrast, be used for strengthening input picture.The detail of each aspect will be provided with helping understand the present invention.But other embodiments of the invention do not need each step comprising these two aspects.Technical staff will be understood that, utilizes other setting contrast scheme of any number, can strengthen picture quality according to the present invention by implementing brilliance control.Or, after use any one known technology carries out image brightness adjustment, image can be strengthened fully by implementing setting contrast.
Fig. 1 describes the basic step of digital image enhancement of the present invention.First input picture 10 carries out brightness adjustment 11.Then, carry out setting contrast 12 through the image I ' of brightness adjustment, produce an output image 13 strengthened.Fig. 2 to Fig. 5 describes each step of brightness adjustment and setting contrast in detail.
With reference to Fig. 2 and 3, the brightness adjustment of input picture 10 comprises the real world brightness L estimated based on and adjusts image brightness, and compression and the image after quantizing brightness adjustment.
Real world estimates that L is input picture I, is used for the function of scale factor (scaling factor) S and minimum brightness parameter τ carrying out adjusting between dynamic range of images and real world dynamic range.
The dynamic range D of input picture I is:
The following equation of image I is obtained after rearranging:
I＝Exp(D×log(I
max+1))-1
If restriction minimum brightness is to τ, so the adjustment dynamic range of image becomes:
Again rearrange, and introduce scale factor S, obtain the image I of brightness adjustment
adjfollowing equation:
I
adj＝Exp(D
adj×S)-1+τ
Wherein S is the scale factor of real world dynamic range, and τ is minimum brightness.
In preferred embodiment, brightness adjustment image I
adjdynamic range be compressed by a Log function, and to be quantized (step 22), to be carried out quantification emulation by human eye.Log compresses equation:
I′＝log(I
adj)
Image quantization is 256 centrifugal pumps in the scope of 0 to 255.
Fig. 4 and Fig. 5 describes the setting contrast of brightness adjustment image I '.The image I ' of adjustment is divided into its low frequency and HFS I
band I
c.Based on low frequency background parts I
b, adjust high frequency contrast part I
c.First, by applying an edge (edge-preserved) low pass filter (EPF) to brightness adjustment image I ', obtain low frequency background parts I
b(step 40).Then by use subtracter 42, image background I is removed from original input picture I
b, obtain high frequency contrast part I
c(step 41).
Then, high frequency contrast part I
ccarry out setting contrast (step 43).Use a Contrast Enhancing Function (EnF), based on image background part I
b, determine a setting contrast level (Lev).Between the minimum and greatest limit that adjustment level (Lev) experience of constraining in is determined.The equation of adjustment level is:
Lev＝(Lev
max-Lev
min)×I
B+Lev
min
Wherein Lev
maxand Lev
minit is the minimum and maximum limit of the adjustment level that experience is determined.
The high frequency contrast part I of adjustment image
cadjusted by adjustment level (Lev) in product module 45.Then, by addition module 43 by background parts I
bbe increased to the contrast part I after adjustment
c, and obtain final enhancing output image 13.
Although described various function and equation, this has not been be intended to limit the scope of application of the present invention or function.Also can use in the present invention those technical staff be familiar with this method equivalent function and equation and variation thereof.
Claims (22)
1. a digital image enhancement method, comprising:
The brightness of adjustment input picture and obtain the image of a brightness adjustment, comprise: estimate the real world brightness of input picture, adjustment image is to the brightness estimated and compression adjusts the dynamic range of image, the real world brightness of estimation is input picture I, be used for the function of scale factor (scaling factor) S and minimum brightness parameter τ carrying out adjusting between dynamic range of images and real world dynamic range;
A low pass filter is used to extract background information from the image of brightness adjustment,
Background information is deleted to extract contrast information from the image of brightness adjustment,
Adjustment contrast information, and
Merge the contrast information after background information and adjustment and obtain output image.
2. method according to claim 1, wherein adjusting image has an equation:
I
adj＝Exp(D
adj×S)-1+τ
Wherein Iadj is adjustment image, D
adjbe the adjustment dynamic range of image, S is the scale factor of real world dynamic range, and τ controls minimum brightness.
3. method according to claim 2, wherein S is from the scope of 6 to 8.
4. method according to claim 2, wherein D
adjequation be:
i
maxit is the high-high brightness of the real world of catching.
5. method according to claim 1, wherein the dynamic range of adjustment adjustment image comprises compression of dynamic range and quantized image.
6. method according to claim 5, wherein compression of dynamic range comprises use function I'=log (I
adj) compress, I' is the image brightness values after quantizing, I
adjadjustment image:
I
adj＝Exp(D
adj×S)-1+τ
Wherein, D
adjbe the adjustment dynamic range of image, S is the scale factor of real world dynamic range, and τ controls minimum brightness.
7. method according to claim 5, wherein quantized image comprises and quantizes to 256 centrifugal pumps.
8. method according to claim 1, wherein low pass filter is a holding edge filter device (edge-preserve filter).
9. method according to claim 1, wherein adjusts contrast information and comprises contrast information is multiplied by a setting contrast factor.
10. method according to claim 9, wherein the setting contrast factor is the function of a background information.
11. methods according to claim 9, wherein the setting contrast factor uses equation:
Lev＝(Lev
max-Lev
min)×I
B+Lev
min
Wherein Lev is the setting contrast factor, Lev
maxand Lev
minthe minimum and maximum limit respectively, I
bit is image background part.
12. 1 kinds of digital image enhancement methods, be used for adjusting the brightness of input picture to obtain a brightness adjustment image, comprise: estimate the real world brightness of input picture, adjustment image is to the brightness estimated and compression adjusts the dynamic range of image, the real world brightness of estimation is input picture I, be used for the function of scale factor (scaling factor) S and minimum brightness parameter τ carrying out adjusting between dynamic range of images and real world dynamic range.
13. methods according to claim 12, wherein adjusting image has an equation:
I
adj＝Exp(D
adj×S)-1+τ
Wherein I
adjadjustment image, D
adjbe the adjustment dynamic range of image, S is the scale factor of real world dynamic range, and τ controls minimum brightness.
14. methods according to claim 13, wherein S is in the scope of 6 to 8.
15. methods according to claim 13, D
adjan equation:
i
maxit is the high-high brightness of the real world of catching.
16. methods according to claim 12, the dynamic range wherein adjusting estimated brightness comprises: Shrinkage estimation brightness also quantizes the brightness of Shrinkage estimation.
17. methods according to claim 16, wherein compression of dynamic range comprises use function I'=log (I
adj) compress, I' is the image brightness values after quantizing, I
adjadjustment image:
I
adj＝Exp(D
adj×S)-1+τ
Wherein, D
adjbe the adjustment dynamic range of image, S is the scale factor of real world dynamic range, and τ controls minimum brightness.
18. methods according to claim 16, the estimated brightness wherein quantizing to compress comprises quantizes to 256 centrifugal pumps.
19. 1 kinds of digital image enhancement methods, are used for correcting the contrast from the brightness adjustment image according to claim 12 gained, comprise:
A low pass filter is utilized to extract the background information of input picture,
Background information is deleted to extract the contrast information of input picture from input picture,
Adjustment contrast information, and
Merge the contrast information of background information and adjustment to obtain an output image.
20. methods according to claim 19, wherein low pass filter is a holding edge filter device.
21. methods according to claim 19, wherein adjust contrast information and comprise contrast information is multiplied by a setting contrast factor.
22. methods according to claim 21, wherein the setting contrast factor is the function of a background information.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2008/072189 WO2010022558A1 (en) | 2008-08-28 | 2008-08-28 | Digital image enhancement |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101578855A CN101578855A (en) | 2009-11-11 |
| CN101578855B true CN101578855B (en) | 2015-07-29 |
Family
ID=41720778
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200880000107.9A Active CN101578855B (en) | 2008-08-28 | 2008-08-28 | digital image enhancement |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN101578855B (en) |
| WO (1) | WO2010022558A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8311361B2 (en) | 2008-08-21 | 2012-11-13 | Hong Kong Applied Science and Technology Research Institute Company Limited | Digital image enhancement |
| CN103901378B (en) * | 2012-12-26 | 2018-01-12 | 深圳联影医疗科技有限公司 | The brightness control system and method for image in magnetic resonance system |
| CN109274949A (en) * | 2018-10-30 | 2019-01-25 | 京东方科技集团股份有限公司 | A kind of method of video image processing and its device, display equipment |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1172312A (en) * | 1996-05-21 | 1998-02-04 | 三星电子株式会社 | Image enhancing method using lowpass filtering and histogram equalization and device thereof |
| JP2005039458A (en) * | 2003-07-18 | 2005-02-10 | Canon Inc | Image processing apparatus and method |
| CN101098489A (en) * | 2006-06-27 | 2008-01-02 | 三星电子株式会社 | Image processing apparatus and method of enhancing visibility of displayed image |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0856316A (en) * | 1994-06-09 | 1996-02-27 | Sony Corp | Image processor |
| JP4274590B2 (en) * | 1997-01-20 | 2009-06-10 | オリンパス株式会社 | Image processing device |
| EP0963111A1 (en) * | 1998-06-02 | 1999-12-08 | Deutsche Thomson-Brandt Gmbh | Method and apparatus for dynamic contrast improvement in video pictures |
| JP3744778B2 (en) * | 2000-08-28 | 2006-02-15 | セイコーエプソン株式会社 | Image projection apparatus, image processing method, and information storage medium |
| KR100467610B1 (en) * | 2002-09-06 | 2005-01-24 | 삼성전자주식회사 | Method and apparatus for improvement of digital image quality |
| KR100484163B1 (en) * | 2002-09-14 | 2005-04-19 | 삼성전자주식회사 | Method and apparatus for improvement of digital image quality |
| US20070076971A1 (en) * | 2005-09-30 | 2007-04-05 | Nokia Corporation | Compression of images for computer graphics |
| KR100879536B1 (en) * | 2006-10-30 | 2009-01-22 | 삼성전자주식회사 | Method And System For Image Enhancement |
| CA2669028C (en) * | 2006-11-27 | 2016-01-12 | Dolby Laboratories Licensing Corporation | Apparatus and methods for boosting dynamic range in digital images |
-
2008
- 2008-08-28 WO PCT/CN2008/072189 patent/WO2010022558A1/en active Application Filing
- 2008-08-28 CN CN200880000107.9A patent/CN101578855B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1172312A (en) * | 1996-05-21 | 1998-02-04 | 三星电子株式会社 | Image enhancing method using lowpass filtering and histogram equalization and device thereof |
| JP2005039458A (en) * | 2003-07-18 | 2005-02-10 | Canon Inc | Image processing apparatus and method |
| CN101098489A (en) * | 2006-06-27 | 2008-01-02 | 三星电子株式会社 | Image processing apparatus and method of enhancing visibility of displayed image |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101578855A (en) | 2009-11-11 |
| WO2010022558A1 (en) | 2010-03-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102438097B (en) | Visual processing device, visual processing method | |
| EP1397780B1 (en) | Image enhancement methods and apparatus therefor | |
| US7433514B2 (en) | Tone mapping of high dynamic range images | |
| US8654221B2 (en) | Image processing device and method, and program | |
| EP2624204B1 (en) | Image processing apparatus and method of controlling the same | |
| CN101690226B (en) | Statistic image improving method, image encoding method, and image decoding method | |
| WO2015096955A1 (en) | Method for inverse tone mapping of an image | |
| CN111429357B (en) | Training data determining method, video processing method, device, equipment and medium | |
| CN107895350B (en) | HDR image generation method based on self-adaptive double gamma transformation | |
| CN103702116B (en) | A kind of dynamic range compression method and apparatus of image | |
| CN102339461A (en) | Method and equipment for enhancing image | |
| Wharton et al. | Human visual system based similarity metrics | |
| CN103380451B (en) | Video display device | |
| CN101578855B (en) | digital image enhancement | |
| Meylan et al. | Bio-inspired color image enhancement | |
| KR20200127439A (en) | Image processing method and apparatus thereof | |
| KR101668829B1 (en) | Texture enhancement method and apparatus reflected human visual characteristic on spatial frequency | |
| CN105791849A (en) | Image compression method and device | |
| US8311361B2 (en) | Digital image enhancement | |
| US20230057829A1 (en) | Encoder, decoder, system, and method for determining tone mapping curve parameters | |
| KR101514152B1 (en) | Method and apparatus for improving image quality using singular value decomposition | |
| Biswas et al. | Automatic contrast enhancement of low-light images based on Naka-Rushton visual adaptation in non-sub-sampled shearlet domain | |
| KR100701306B1 (en) | The device of processing the shoot artifact in the image signal and the method thereof | |
| CN107292829B (en) | Image processing method and device | |
| KR102556960B1 (en) | Sampled chrominance component restoration device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |