WO2010022558A1 - Digital image enhancement - Google Patents

Digital image enhancement Download PDF

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Publication number
WO2010022558A1
WO2010022558A1 PCT/CN2008/072189 CN2008072189W WO2010022558A1 WO 2010022558 A1 WO2010022558 A1 WO 2010022558A1 CN 2008072189 W CN2008072189 W CN 2008072189W WO 2010022558 A1 WO2010022558 A1 WO 2010022558A1
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WO
WIPO (PCT)
Prior art keywords
image
contrast
brightness
adjusting
information
Prior art date
Application number
PCT/CN2008/072189
Other languages
French (fr)
Inventor
Min Chen
Huajun Peng
Guoping Qiu
Original Assignee
Hong Kong Applied Science and Technology Research Institute Co. Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hong Kong Applied Science and Technology Research Institute Co. Ltd filed Critical Hong Kong Applied Science and Technology Research Institute Co. Ltd
Priority to CN200880000107.9A priority Critical patent/CN101578855B/en
Priority to PCT/CN2008/072189 priority patent/WO2010022558A1/en
Publication of WO2010022558A1 publication Critical patent/WO2010022558A1/en

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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

Definitions

  • the current invention relates to digital image enhancement, and in particular to methods of enhancing the brightness and the contrast of a digital image.
  • a digital image enhancement method for adjusting the brightness of an input image to obtain a brightness adjusted image and then adjusting the contrast of the brightness adjusted image to obtain an enhanced output image.
  • Adjusting the brightness of the input image preferably comprises estimating a real world luminance of the input image.
  • the dynamic range of the adjusted image is compressed and the brightness enhanced image quantized.
  • Contrast adjustment preferably comprises extracting background and contrast information of the brightness enhanced image, adjusting the contrast information, and combining the background and adjusted contrast information to obtain an output image.
  • the background information may first be obtained using a low pass filter and then the background information is removed from the original image to obtain the contrast information.
  • the contrast information is adjusted by multiplying by a contrast adjustment factor, which is a function of the background information.
  • FIG. 1 is a schematic block diagram of the basic steps for image enhancement according to the invention
  • Figure 2 is a schematic block diagram showing more detail of a brightness adjustment step
  • Figure 3 is a functional block diagram of the brightness adjustment
  • Figure 4 is a schematic block diagram showing more detail of a contrast adjustment step
  • Figure 5 is a functional block diagram of contrast adjustment. Description of the preferred Embodiments
  • the following exemplary embodiments of the present invention are given by way of example only and are not intended to limit the scope of use or functionality of the invention.
  • the invention comprises two aspects, namely brightness adjustment and contrast adjustment, for enhancing an input image. Specific detail of each aspect is given to assist in understanding the invention. However, alternative embodiments of the invention need not comprise every step in both aspects.
  • the skilled addressee will appreciate that the quality of an image will be enhanced by practising brightness control according to the invention with any number of alternative contrast adjustment schemes. Alternatively the image may be adequately enhanced by practising contrast adjustment after brightness adjustment of an image using any one of a number of known techniques.
  • Figure 1 illustrates basic steps in digital image enhancement according to the invention.
  • An input image 10 firstly undergoes brightness adjustment 11.
  • the brightness adjusted image F then undergoes contrast adjustment 12 resulting in an enhanced output image 13.
  • Figures 2 through 5 illustrate in more detail each of the steps of brightness adjustment and contrast adjustment.
  • brightness adjustment of the input image 10 consists of adjusting the brightness of the image based in an estimated real world luminance L, and compressing and quantizing the brightness adjusted image.
  • the real world estimation L is a function of the input image /, a scaling factor S to adjust between an image dynamic range and the real word dynamic range, and a minimum luminance parameter ⁇ .
  • the dynamic range D of the input image / is:
  • the dynamic range of the brightness adjusted image I a ⁇ - is compressed by a log function and quantized 22 to simulate quantization by the human eye.
  • the log compression equation is:
  • Quantization of the image is to 256 discrete values in the range 0 to 255.
  • Figures 4 and 5 illustrate contrast adjustment of the brightness adjusted image /'.
  • the adjusted image /' is split in to its high and low frequency components I B and Ic
  • the high frequency contrast component Ic is adjusted based on the low frequency background component I B Firstly the low frequency background component I B is obtained 40 by applying an edge-preserved low pass filter (EPF) to the brightness adjusted image /'.
  • the high frequency contrast component Ic is then obtained 41 by removing the image background I B from the original input image /using a subtractor 42.
  • EPF edge-preserved low pass filter
  • a contrast adjustment level (Lev) is determined based on the image background component I B using a contrast enhancement function (EnF).
  • the adjustment level (Lev) is constrained between empirically determined minimum and maximum limits.
  • the equation for the adjustment level is:
  • Lev (Lev max - Lev min jx/g H Lev min
  • Lev max and Lev m ⁇ n are the empirically determined maximum and minimum limits of the adjustment level.
  • the high frequency contrast component Ic of the image is adjusted by the adjustment level (Lev) at a product block 45.
  • the final enhanced output image 13 is then obtained by adding the background component I B to the adjusted contrast component Ic at an addition block 43.

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  • 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

Enhancement of an image includ es adjusting its brightness and then adjusting the contrast of the brightness adjusted image. Adjusti ng the brightness uses an estimation of real world luminance. Contrast adjustment involves extracting ba ckground and contrast information, adjusting the contrast inform ation by an adjustment factor based on the background information and combining the back ground corrected contrast information to obtain an output image.

Description

Digital Image Enhancement
Background to the invention
1. Field of the Invention
The current invention relates to digital image enhancement, and in particular to methods of enhancing the brightness and the contrast of a digital image.
2. Background Information Digital images, either still or video, are not always captured under ideal lighting conditions. Natural lighting conditions can often be too bright or too dim and artificial lighting outside of a photographic studio often provides irregular illumination. This results in the captured image having poor visual quality.
Various techniques have been proposed in the art for improving or enhancing image quality. More recent methods of enhancing an image are disclosed in US patent publications US 2008/0101719 to Lim et al, US 2008/0012992 and 2007/0171310 to Arici et al and US 2007/0071350 to Lee et al. US publication 2008/0101719 to Lim, in particular, gives a good discussion on the various well known techniques for improving image quality. All of these various methods are successful in improving image quality to varying degrees.
Summary of the invention
There is disclosed herein a digital image enhancement method for adjusting the brightness of an input image to obtain a brightness adjusted image and then adjusting the contrast of the brightness adjusted image to obtain an enhanced output image.
Adjusting the brightness of the input image preferably comprises estimating a real world luminance of the input image. The dynamic range of the adjusted image is compressed and the brightness enhanced image quantized. Contrast adjustment preferably comprises extracting background and contrast information of the brightness enhanced image, adjusting the contrast information, and combining the background and adjusted contrast information to obtain an output image.
To extract the background and contrast information the background information may first be obtained using a low pass filter and then the background information is removed from the original image to obtain the contrast information.
The contrast information is adjusted by multiplying by a contrast adjustment factor, which is a function of the background information.
Brief Description of the Drawings
Exemplary forms of the present invention will now be described by way of example only and with reference to the accompanying drawings in which:
Figure 1 is a schematic block diagram of the basic steps for image enhancement according to the invention,
Figure 2 is a schematic block diagram showing more detail of a brightness adjustment step,
Figure 3 is a functional block diagram of the brightness adjustment,
Figure 4 is a schematic block diagram showing more detail of a contrast adjustment step, and
Figure 5 is a functional block diagram of contrast adjustment. Description of the preferred Embodiments
The following exemplary embodiments of the present invention are given by way of example only and are not intended to limit the scope of use or functionality of the invention. The invention comprises two aspects, namely brightness adjustment and contrast adjustment, for enhancing an input image. Specific detail of each aspect is given to assist in understanding the invention. However, alternative embodiments of the invention need not comprise every step in both aspects. The skilled addressee will appreciate that the quality of an image will be enhanced by practising brightness control according to the invention with any number of alternative contrast adjustment schemes. Alternatively the image may be adequately enhanced by practising contrast adjustment after brightness adjustment of an image using any one of a number of known techniques.
Figure 1 illustrates basic steps in digital image enhancement according to the invention. An input image 10 firstly undergoes brightness adjustment 11. The brightness adjusted image F then undergoes contrast adjustment 12 resulting in an enhanced output image 13. Figures 2 through 5 illustrate in more detail each of the steps of brightness adjustment and contrast adjustment.
Referring to Figures 2 and 3, brightness adjustment of the input image 10 consists of adjusting the brightness of the image based in an estimated real world luminance L, and compressing and quantizing the brightness adjusted image.
The real world estimation L is a function of the input image /, a scaling factor S to adjust between an image dynamic range and the real word dynamic range, and a minimum luminance parameter τ.
The dynamic range D of the input image / is:
Log(I Λ I) D =
1Og(1MOX + 1) Rearranging we get the following equation for the image /:
/ = Exp(Dxlog(Imax -\ l)) - l
If we limit the minimum luminance toτ then the adjusted dynamic range of the image becomes:
D _ Log(I - τ) λ 1 3 log(Imax + l)
Rearranging again and introducing the scaling factor S we get the following equation for the brightness adjusted image Iaφ :
Iadj = Exp(Dadj XS) - U τ
where S is the scaling factor of the real word dynamic range, and τ is the minimum luminance.
In the preferred embodiment the dynamic range of the brightness adjusted image Iaφ- is compressed by a log function and quantized 22 to simulate quantization by the human eye. The log compression equation is:
I'= log(Iadj )
Quantization of the image is to 256 discrete values in the range 0 to 255.
Figures 4 and 5 illustrate contrast adjustment of the brightness adjusted image /'. The adjusted image /' is split in to its high and low frequency components IB and Ic The high frequency contrast component Ic is adjusted based on the low frequency background component IB Firstly the low frequency background component IB is obtained 40 by applying an edge-preserved low pass filter (EPF) to the brightness adjusted image /'. The high frequency contrast component Ic is then obtained 41 by removing the image background IB from the original input image /using a subtractor 42.
The high frequency contrast component Ic then undergoes contrast adjustment 43. A contrast adjustment level (Lev) is determined based on the image background component IB using a contrast enhancement function (EnF). The adjustment level (Lev) is constrained between empirically determined minimum and maximum limits. The equation for the adjustment level is:
Lev = (Levmax - Levmin jx/g H Levmin
where Levmax and Levmιn are the empirically determined maximum and minimum limits of the adjustment level.
The high frequency contrast component Ic of the image is adjusted by the adjustment level (Lev) at a product block 45. The final enhanced output image 13 is then obtained by adding the background component IB to the adjusted contrast component Ic at an addition block 43.
Various functions and equations have been described which are not intended to limit the scope of use or functionality of the invention. Equivalent functions and equations and variations of the method obvious to those skilled may also be used in the invention.

Claims

What is Claimed is:
1. A digital image enhancement method comprising: adjusting the brightness of an input image to obtain a brightness adjusted image, extracting background information from the brightness adjusted image, extracting contrast information from the brightness adjusted image, adjusting the contrast information, and combining the background information and adjusted contrast information to obtain an output image.
2. The method of claim 1 wherein adjusting the brightness of the input image to obtain the brightness adjusted image comprises estimating a luminance for the input image, adjusting the image to the estimated luminance and compressing the dynamic range of the adjusted image.
3. The method of claim 2 wherein estimating the luminance of the input image comprises estimating using a estimating function including factors for a real world dynamic range and a minimum luminance.
4. The method of claim 3 wherein the adjusted image has an equation: Iadj = ExP(Dadj ^S)- lλ τ where Iadj is the adjusted image, S is a scaling factor of the real word dynamic range, and τ controls the minimum luminance.
5. The method of claim 4 wherein S is in a range from 6 to 8.
6. The method of claim 4 wherein Dadj is an equation having a form:
Figure imgf000007_0001
7. The method of claim 3 wherein adjusting the dynamic range of the adjusted image comprises compressing the dynamic range and quantization of the image.
8. The method of claim 7 wherein compressing the dynamic range comprises compressing using a function /'= log(IeSf ) .
9. The method of claim 7 wherein quantization of the image comprises quantizing to 256 discrete values.
10. The method of claim 1 wherein extracting background information of the brightness adjusted image comprises extracting with a low pass filter.
11. The method of claim 10 wherein the low pass filter is an edge-preserve filter.
12. The method of claim 1 wherein extracting contrast information of the brightness adjusted image comprises removing the background information from the input image.
13. The method of claim 1 wherein adjusting the contrast information comprises multiplying the contrast information by a contrast adjustment factor.
14. The method of claim 13 wherein the contrast adjustment factor is a function of the background information.
15. The method of claim 13 wherein the contrast adjustment factor uses the equation Lev = (Levmax - Levmin )xIB λ Levmin where Lev is the contrast adjustment factor, aΑάLevmax and Levmιn are maximum and minimum limits respectively.
16. A digital image enhancement method, for adjusting the brightness of an input image to obtain a brightness adjusted image, comprising estimating a luminance for the input image, adjusting the image to the estimated luminance and compressing the dynamic range of the adjusted image.
17. The method of claim 16 wherein estimating the luminance of the input image comprises estimating using a estimating function including factors for a real world dynamic range and a minimum luminance.
18. The method of claim 17 wherein the adjusted image has an equation: Iadj = Exp(DadJ xS)- U τ where Iadj is the adjusted image, S is a scaling factor of the real word dynamic range, and τ controls the minimum luminance.
19. The method of claim 18 wherein S is in a range from 6 to 8.
20. The method of claim 18 wherein Daφ- is an equation having a form: Log [(I - τ) Λ 1
Dadj =
1Og(1MOX + 1)
21. The method of claim 17 wherein adjusting the dynamic range of the estimated luminance comprises compression of the estimated luminance and quantization of the compressed estimated luminance.
22. The method of claim 21 wherein compressing the dynamic range comprises compressing using a function /' = log(Iest ) .
23. The method of claim 21 wherein quantization of the compressed estimated luminance comprises quantizing to 256 discrete values.
24. A digital image enhancement method, for correcting the contrast of an input image, comprising: extracting background information of the input image, extracting contrast information of the input image, adjusting the contrast information, and combining the background information and adjusted contrast information to obtain an output image.
25. The method of claim 24 wherein extracting background information of the brightness adjusted image comprises extracting with a low pass filter.
26. The method of claim 25 wherein the low pass filter is a edge-preserve filter.
27. The method of claim 24 wherein extracting contrast information of the brightness adjusted image comprises removing the background information from the input image.
28. The method of claim 24 wherein adjusting the contrast information comprises multiplying the contrast information by a contrast adjustment factor.
29. The method of claim 26 wherein the contrast adjustment factor is a function of the background information.
PCT/CN2008/072189 2008-08-28 2008-08-28 Digital image enhancement WO2010022558A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
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

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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 (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0856316A (en) * 1994-06-09 1996-02-27 Sony Corp Image processor
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
JPH10210324A (en) * 1997-01-20 1998-08-07 Olympus Optical Co Ltd Image-processing unit
JP2005039458A (en) * 2003-07-18 2005-02-10 Canon Inc Image processing apparatus and method
US7170645B2 (en) * 2002-09-06 2007-01-30 Samsung Electronics Co., Ltd. Method and apparatus for enhancing digital image quality
US7187808B2 (en) * 2002-09-14 2007-03-06 Samsung Electronics Co., Ltd. Method and apparatus for enhancing digital image quality
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
US20080101719A1 (en) * 2006-10-30 2008-05-01 Samsung Electronics Co., Ltd. Image enhancement method and system

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
US20070076971A1 (en) * 2005-09-30 2007-04-05 Nokia Corporation Compression of images for computer graphics
KR101466596B1 (en) * 2006-11-27 2014-11-28 돌비 레버러토리즈 라이쎈싱 코오포레이션 Apparatus and methods for boosting dynamic range in digital images

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0856316A (en) * 1994-06-09 1996-02-27 Sony Corp Image processor
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
JPH10210324A (en) * 1997-01-20 1998-08-07 Olympus Optical Co Ltd Image-processing unit
US7170645B2 (en) * 2002-09-06 2007-01-30 Samsung Electronics Co., Ltd. Method and apparatus for enhancing digital image quality
US7187808B2 (en) * 2002-09-14 2007-03-06 Samsung Electronics Co., Ltd. Method and apparatus for enhancing digital image quality
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
US20080101719A1 (en) * 2006-10-30 2008-05-01 Samsung Electronics Co., Ltd. Image enhancement method and system

Cited By (1)

* Cited by examiner, † Cited by third party
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

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CN101578855B (en) 2015-07-29

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