CN107369144A - Based on the multiple dimensioned Retinex images defogging method for improving homomorphic filtering - Google Patents

Based on the multiple dimensioned Retinex images defogging method for improving homomorphic filtering Download PDF

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CN107369144A
CN107369144A CN201710565491.8A CN201710565491A CN107369144A CN 107369144 A CN107369144 A CN 107369144A CN 201710565491 A CN201710565491 A CN 201710565491A CN 107369144 A CN107369144 A CN 107369144A
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范保杰
戴飞
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Nanjing Post and Telecommunication University
Nanjing University of Posts and Telecommunications
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    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T5/00Image enhancement or restoration
    • G06T5/73Deblurring; Sharpening

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Abstract

The invention discloses a kind of based on the multiple dimensioned Retinex images defogging method for improving homomorphic filtering, belong to technical field of image processing, comprise the following steps:Step 01:Input foggy image I(x);Step 02:To traditional homomorphic filtering transfer function H(U, v)It is improved;Step 03:By foggy image I(x)Tri- color channel images of R, G, B are decomposed into, the homomorphic filtering processing after being improved respectively to each Color Channel;Step 04:Multi-Scale Retinex Algorithm processing is carried out respectively to the filtered channel image obtained in step 03;Step 05:The channel image that step 04 is obtained merges, and obtains the image after defogging.It is an advantage of the invention that:Improve defog effect so that the picture contrast height after defogging, details are clear, and computation complexity is low, speed is fast.

Description

Based on the multiple dimensioned Retinex images defogging method for improving homomorphic filtering
Technical field
It is more particularly to a kind of based on the multiple dimensioned of improvement homomorphic filtering the present invention relates to technical field of image processing Retinex image defogging methods.
Background technology
Haze occurs in China frequently and distributed areas are wide, is a kind of common weather phenomenon.Influenceed by haze, imaging is set It is standby to be difficult to and extract characteristics of image, our life therefore can be by a certain degree of influence, such as under haze weather Traffic accident incidence increases, and the picture contrast that monitoring system is shot is low, is difficult to extract feature of personage etc..
In defogging method based on image enhaucament, homomorphic filtering and Retinex algorithm are two kinds of representative defoggings Algorithm, both algorithms are all based on irradiating reflection model, it is intended to remove irradiation light and retain reflected light so as to obtain image original This color, but Homomorphic Filtering Algorithm defog effect is bad, contrast is poor after Retinex algorithm defogging, details is unintelligible, and The problems such as cross-color occurs.
The content of the invention
The technical problems to be solved by the invention are the defects of being directed to background technology, are proposed a kind of based on improvement homomorphic filtering Multiple dimensioned Retinex images defogging method, how realization be efficiently modified that mist elimination image mist residual is excessive, details is unintelligible The problem of.
The present invention above-mentioned technical problem technical scheme is that:
A kind of multiple dimensioned Retinex images defogging method based on improvement homomorphic filtering, comprises the following steps:
Step 01:Input foggy image I (x);
Step 02:Traditional homomorphic filtering transfer function H (u, v) is improved, traditional H (u, v) expression formula is:It is as follows to improve step:
a:Cut-off frequency D is seto
b:To cut-off frequency in DoWithin part suppressed;
c:To cut-off frequency in DoPart above is strengthened;
d:Setting removes cut-off frequency DoOther specification numerical value in addition, obtain improved homomorphic filtering transmission function expression Formula:
Wherein rHRepresent high-frequency gain, rLLow-frequency gain is represented, and meets rH>1,rL<1, D (u, v) represents frequency (u, v) To filter center (uo,vo) distance, DoCut-off frequency is represented, coefficient c is used to control sharpness, and size is between rHAnd rLIt Between;
Step 03:Foggy image I (x) is decomposed into tri- color channel images of R, G, B, each Color Channel is entered respectively Homomorphic filtering after row improves is handled;
Step 04:Multi-Scale Retinex Algorithm processing is carried out respectively to the filtered channel image obtained in step 03;
Step 05:The channel image that step 04 is obtained merges, and obtains the image after defogging.
Further, wherein, rH=1.5, rL=0.5, c=1, Do=4.
Further, multi-Scale Retinex Algorithm expression formula is in step 04:
Wherein ri(x, y) represents the output in i-th of passage, Si(x, y) represents the foggy image of i-th of passage input, i Value be 1,2,3;N represents the number of scale parameter;ωnThe weight of each scale parameter is represented, and is metFn (x, y) is to surround function, and * represents convolution.
Further, around function FnThe expression formula of (x, y) is:
Wherein λnIt is normalization factor, b represents scale parameter.
Further, ∫ ∫ Fn(x, y) dxdy=1.
Further, wherein N value takes 3, and the scale parameter is set to 15,100,240.The present invention uses above skill Art scheme compared with prior art, has following technique effect:
It is proposed by the present invention a kind of based on the multiple dimensioned Retinex images defogging method for improving homomorphic filtering, using filter Ripple has used improved new forestry when handling foggy image, while carries out high LPF, to cut-off frequency in DoWithin Part suppressed, that is, inhibit the stronger part of irradiation component;To cut-off frequency in DoPart above is increased By force, that is, the details of image is enhanced;The foggy image I (x) of input tri- Color Channels of RGB are carried out at homomorphic filtering respectively Reason, reach the effect for suppressing irradiation component and compression of dynamic range;Multi-Scale Retinex Algorithm processing is carried out again to each passage; Each channel image after processing is merged, obtains final defogging result.Defogging speed of the present invention is fast, improves defogging effect Fruit, the problem of multiple dimensioned Retinex defoggings mist residual is excessive is improved, details picture rich in detail contrast is strong after defogging, has real The property used.
Brief description of the drawings
Fig. 1 is the schematic flow sheet of the present invention;
Fig. 2 positions present invention and homomorphic filtering and the comparison diagram of multi-Scale Retinex Algorithm.
Embodiment
The present invention is described in further detail below in conjunction with accompanying drawing.
First, as shown in figure 1, a kind of multiple dimensioned Retinex images based on improvement homomorphic filtering provided by the invention are gone Mist method, it specifically includes following step:
Step 01:Input foggy image I (x);
Step 02:Traditional homomorphic filtering transfer function H (u, v) is improved, traditional H (u, v) expression formula is:It is as follows to improve step:
a:Cut-off frequency D is seto
b:To cut-off frequency in DoWithin part suppressed;
c:To cut-off frequency in DoPart above is strengthened;
d:Setting removes cut-off frequency DoOther specification numerical value in addition, obtain improved homomorphic filtering transmission function expression Formula:
Wherein rHRepresent high-frequency gain, rLLow-frequency gain is represented, and meets rH>1,rL<1, D (u, v) represents frequency (u, v) To filter center (uo,vo) distance, DoCut-off frequency is represented, coefficient c is used to control sharpness, and size is between rHAnd rLIt Between;
Step 03:Foggy image I (x) is decomposed into tri- color channel images of R, G, B, each Color Channel is entered respectively Homomorphic filtering after row improves is handled;
Step 04:Multi-Scale Retinex Algorithm processing is carried out respectively to the filtered channel image obtained in step 03;
Step 05:The channel image that step 04 is obtained merges, and obtains the image after defogging.
Wherein rHRepresent high-frequency gain, rLLow-frequency gain is represented, D (u, v) represents that frequency (u, v) arrives filter center (uo, vo) distance, DoCut-off frequency is represented, coefficient c is used to control sharpness, and size is between rHAnd rLBetween.It is improved new same State filter transfer function is respectively to cut-off frequency DoThe part of both sides carries out low pass and high-pass filtering processing, to cut-off frequency in Do Within part suppressed, that is, inhibit the stronger part of irradiation component;To cut-off frequency in DoPart above is carried out Enhancing, that is, enhance the details of image.
Step 03:Foggy image I (x) is decomposed into tri- color channel images of R, G, B, each Color Channel is entered respectively Homomorphic filtering after row improves is handled;
Specifically, tri- color channel images of R, G, B for being decomposed into of foggy image I (x) for I (:,:,1)、I(:,:,2)、I (:,:, 3), be filtered respectively processing after result for I_filt (:,:,1)、I_filt(:,:,2)、I_filt(:,:,3).
Step 04:Multi-Scale Retinex Algorithm processing is carried out respectively to the filtered channel image obtained in step 03;
Step 05:The channel image that step 04 is obtained merges, and obtains the image after defogging.
Specifically, the expression formula of multi-Scale Retinex Algorithm is:
Wherein ri(x, y) represents the output in i-th of passage, Si(x, y) represents the foggy image of i-th of passage input, i Value be 1,2,3.N represents the number of scale parameter, usually 3, it is divided into 3 small yardstick, mesoscale, large scale yardsticks ginsengs Number, wherein scale parameter are set to 15,100,240 and allow multi-Scale Retinex Algorithm to have single scale Retinex calculations concurrently The advantages of when method takes small, middle and high yardstick.ωnThe weight of each scale parameter is represented, and is metFn(x, y) is ωn Corresponding n-th around function, * expression convolution.
Wherein, around function FnThe expression formula of (x, y) is:
Wherein λnIt is normalization factor, b represents scale parameter, ∫ ∫ Fn(x, y) dxdy=1.
After filtering process channel image I_filt (:,:,1)、I_filt(:,:,2)、I_filt(:,:, 3) and carry out more chis Spend Retinex algorithm processing after result be I_msr (:,:,1)、I_msr(:,:,2)、I_msr(:,:, 3), finally by merging After obtain defogging result I_msr=unit (I_msr).
Fig. 2 shows the mist elimination image after different several defogging algorithm process.(a), (e) have mist figure for original in Fig. 2 Picture, we carry out defogging using the method for traditional homomorphic filtering, multi-Scale Retinex Algorithm and the present invention to image respectively, its In (b), (f) be using the result after traditional homomorphic filtering defogging, it can be seen that the residual of mist is excessive after defogging, picture contrast Difference;Figure (c), (g) they are to use the result after multi-Scale Retinex Algorithm defogging, it can be seen that there is preferable defog effect, but it is special Determine region such as white construction thing not obtaining strengthening defog effect well, the profile and details of scenery are still relatively fuzzyyer;Figure (d), (h) is to use the result after the inventive method defogging, it can be seen that picture contrast obtains good improvement, the wheel of scenery Wide and texture becomes apparent from, stereovision is clearly demarcated.
This specific embodiment is only explanation of the invention, and it is not limitation of the present invention, people in the art Member can make the modification of no creative contribution to the present embodiment as needed after this specification is read, but as long as at this All protected in the right of invention by Patent Law.

Claims (6)

1. it is a kind of based on the multiple dimensioned Retinex images defogging method for improving homomorphic filtering, it is characterized in that:Comprise the following steps:
Step 01:Input foggy image I (x);
Step 02:Traditional homomorphic filtering transfer function H (u, v) is improved, traditional H (u, v) expression formula is:It is as follows to improve step:
a:Cut-off frequency D is seto
b:To cut-off frequency in DoWithin part suppressed;
c:To cut-off frequency in DoPart above is strengthened;
d:Setting removes cut-off frequency DoOther specification numerical value in addition, obtain improved homomorphic filtering transmission function expression formula:
<mrow> <mi>H</mi> <mrow> <mo>(</mo> <mi>u</mi> <mo>,</mo> <mi>v</mi> <mo>)</mo> </mrow> <mo>=</mo> <mrow> <mo>(</mo> <msub> <mi>r</mi> <mi>H</mi> </msub> <mo>-</mo> <msub> <mi>r</mi> <mi>L</mi> </msub> <mo>)</mo> </mrow> <mo>{</mo> <mfrac> <mn>1</mn> <msup> <mrow> <mo>&amp;lsqb;</mo> <mn>1</mn> <mo>+</mo> <msub> <mi>D</mi> <mi>o</mi> </msub> <mo>/</mo> <mi>c</mi> <mi>D</mi> <mrow> <mo>(</mo> <mi>u</mi> <mo>,</mo> <mi>v</mi> <mo>)</mo> </mrow> <mo>&amp;rsqb;</mo> </mrow> <mn>2</mn> </msup> </mfrac> <mo>+</mo> <mfrac> <mn>1</mn> <msup> <mrow> <mo>&amp;lsqb;</mo> <mn>1</mn> <mo>+</mo> <mi>D</mi> <mrow> <mo>(</mo> <mi>u</mi> <mo>,</mo> <mi>v</mi> <mo>)</mo> </mrow> <mo>/</mo> <msub> <mi>D</mi> <mi>o</mi> </msub> <mo>&amp;rsqb;</mo> </mrow> <mn>2</mn> </msup> </mfrac> <mo>}</mo> <mo>+</mo> <msub> <mi>r</mi> <mi>L</mi> </msub> </mrow>
Wherein rHRepresent high-frequency gain, rLLow-frequency gain is represented, and meets rH>1,rL<1, D (u, v) represents frequency (u, v) to filtering Device center (uo,vo) distance, DoCut-off frequency is represented, coefficient c is used to control sharpness, and size is between rHAnd rLBetween;
Step 03:Foggy image I (x) is decomposed into tri- color channel images of R, G, B, each Color Channel is changed respectively Homomorphic filtering processing after entering;
Step 04:Multi-Scale Retinex Algorithm processing is carried out respectively to the filtered channel image obtained in step 03;
Step 05:The channel image that step 04 is obtained merges, and obtains the image after defogging.
2. the method according to claim 11, it is characterized in that:Wherein, rH=1.5, rL=0.5, c=1, Do=4.
3. the method according to claim 11, it is characterized in that:Multi-Scale Retinex Algorithm expression formula is in step 04:
<mrow> <msub> <mi>r</mi> <mi>i</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>,</mo> <mi>y</mi> <mo>)</mo> </mrow> <mo>=</mo> <munderover> <mo>&amp;Sigma;</mo> <mrow> <mi>n</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <msub> <mi>&amp;omega;</mi> <mi>n</mi> </msub> <mo>{</mo> <mi>log</mi> <mi> </mi> <msub> <mi>S</mi> <mi>i</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>,</mo> <mi>y</mi> <mo>)</mo> </mrow> <mo>-</mo> <mi>l</mi> <mi>o</mi> <mi>g</mi> <mo>&amp;lsqb;</mo> <msub> <mi>F</mi> <mi>n</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>,</mo> <mi>y</mi> <mo>)</mo> </mrow> <mo>*</mo> <msub> <mi>S</mi> <mi>i</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>,</mo> <mi>y</mi> <mo>)</mo> </mrow> <mo>&amp;rsqb;</mo> <mo>}</mo> </mrow>
Wherein ri(x, y) represents the output in i-th of passage, Si(x, y) represents the foggy image of i-th of passage input, and i's takes It is worth for 1,2,3;N represents the number of scale parameter;ωnThe weight of each scale parameter is represented, and is metFn(x,y) It is to surround function, * represents convolution.
4. the method according to claim 11, it is characterized in that:Around function FnThe expression formula of (x, y) is:
<mrow> <msub> <mi>F</mi> <mi>n</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>,</mo> <mi>y</mi> <mo>)</mo> </mrow> <mo>=</mo> <msub> <mi>&amp;lambda;</mi> <mi>n</mi> </msub> <msup> <mi>e</mi> <mrow> <mo>-</mo> <mfrac> <mrow> <mo>(</mo> <msup> <mi>x</mi> <mn>2</mn> </msup> <mo>+</mo> <msup> <mi>y</mi> <mn>2</mn> </msup> <mo>)</mo> </mrow> <mrow> <msup> <msub> <mi>b</mi> <mi>n</mi> </msub> <mn>2</mn> </msup> </mrow> </mfrac> </mrow> </msup> </mrow>
Wherein λnIt is normalization factor, b represents scale parameter.
5. the method according to claim 11, it is characterized in that:∫∫Fn(x, y) dxdy=1.
6. the method according to claim 11, it is characterized in that:Wherein N value takes 3, the scale parameter is set to 15, 100、240。
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108288258A (en) * 2018-04-23 2018-07-17 电子科技大学 A kind of low-quality images Enhancement Method under severe weather conditions
CN109753878A (en) * 2018-12-06 2019-05-14 北京科技大学 Imaging recognition methods and system under a kind of bad weather
CN109829862A (en) * 2019-01-22 2019-05-31 三峡大学 A kind of solar flare image based on multiple dimensioned Retinex removes cloud method
CN110276729A (en) * 2019-06-10 2019-09-24 浙江工业大学 A kind of Enhancement Method of low-luminance color image
CN111161360A (en) * 2019-12-17 2020-05-15 天津大学 Retinex theory-based image defogging method for end-to-end network
CN112613458A (en) * 2020-12-29 2021-04-06 安徽创世科技股份有限公司 Image preprocessing method and device for face recognition

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101783012A (en) * 2010-04-06 2010-07-21 中南大学 Automatic image defogging method based on dark primary colour
CN104200437A (en) * 2014-09-04 2014-12-10 北京工业大学 Image defogging method
CN105844601A (en) * 2016-05-20 2016-08-10 中国矿业大学(北京) Mine image enhancement method based on bilateral filtering and multi-scale Retinex algorithm
CN106355563A (en) * 2016-08-31 2017-01-25 河南工业大学 Image defogging method and device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101783012A (en) * 2010-04-06 2010-07-21 中南大学 Automatic image defogging method based on dark primary colour
CN104200437A (en) * 2014-09-04 2014-12-10 北京工业大学 Image defogging method
CN105844601A (en) * 2016-05-20 2016-08-10 中国矿业大学(北京) Mine image enhancement method based on bilateral filtering and multi-scale Retinex algorithm
CN106355563A (en) * 2016-08-31 2017-01-25 河南工业大学 Image defogging method and device

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
周小军等: "基于改进同态滤波的遥感图像去云算法", 《无线电工程》 *
汪秦峰等: "基于同态滤波和Retinex的图像去雾算法", 《火控雷达技术》 *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108288258A (en) * 2018-04-23 2018-07-17 电子科技大学 A kind of low-quality images Enhancement Method under severe weather conditions
CN108288258B (en) * 2018-04-23 2021-08-10 电子科技大学 Low-quality image enhancement method under severe weather condition
CN109753878A (en) * 2018-12-06 2019-05-14 北京科技大学 Imaging recognition methods and system under a kind of bad weather
CN109829862A (en) * 2019-01-22 2019-05-31 三峡大学 A kind of solar flare image based on multiple dimensioned Retinex removes cloud method
CN110276729A (en) * 2019-06-10 2019-09-24 浙江工业大学 A kind of Enhancement Method of low-luminance color image
CN110276729B (en) * 2019-06-10 2021-12-17 浙江工业大学 Low-illumination color image enhancement method
CN111161360A (en) * 2019-12-17 2020-05-15 天津大学 Retinex theory-based image defogging method for end-to-end network
CN111161360B (en) * 2019-12-17 2023-04-28 天津大学 Image defogging method of end-to-end network based on Retinex theory
CN112613458A (en) * 2020-12-29 2021-04-06 安徽创世科技股份有限公司 Image preprocessing method and device for face recognition

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