CN104408716A - Three-dimensional image quality objective evaluation method based on visual fidelity - Google Patents

Three-dimensional image quality objective evaluation method based on visual fidelity Download PDF

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CN104408716A
CN104408716A CN201410679301.1A CN201410679301A CN104408716A CN 104408716 A CN104408716 A CN 104408716A CN 201410679301 A CN201410679301 A CN 201410679301A CN 104408716 A CN104408716 A CN 104408716A
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point image
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邵枫
李柯蒙
李福翠
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Ningbo University
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    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00Image analysis
    • G06T7/0002Inspection of images, e.g. flaw detection
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00Indexing scheme for image analysis or image enhancement
    • G06T2207/10Image acquisition modality
    • G06T2207/10004Still image; Photographic image
    • G06T2207/10012Stereo images
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00Indexing scheme for image analysis or image enhancement
    • G06T2207/30Subject of image; Context of image processing
    • G06T2207/30168Image quality inspection

Abstract

The invention discloses a three-dimensional image quality objective evaluation method based on visual fidelity. The method includes: in a training stage, selecting multiple original distortionless three-dimensional images to form a training image set, determining whether pixel points in the distortionless three-dimensional images belong to a shielding area or a matching area through area detection, and structuring a monocular vision dictionary table and a binocular vision dictionary table to the training image set through an unsupervised learning mode; in a testing stage, for testing three-dimensional images and the original distortionless three-dimensional images, estimating sparse coefficient array of each subblock, belonging to the shielding area and the matching area, in the testing three-dimensional images and the corresponding distortionless three-dimensional images according to the monocular vision dictionary table and the binocular vision dictionary table, calculating monocular image quality objective evaluation prediction value and binocular image quality objective evaluation prediction value through the sparse coefficient array, and finally combining to acquire an image quality evaluation predication value. The three-dimensional image quality objective evaluation method has the advantage that the acquired image quality objective evaluation predication value is highly uniform with a subjective evaluation value.

Description

The objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity
Technical field
The present invention relates to a kind of image quality evaluating method, especially relate to the objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity.
Background technology
Along with developing rapidly of image coding technique and stereo display technique, stereo-picture technology receives to be paid close attention to and application more and more widely, has become a current study hotspot.Stereo-picture technology utilizes the binocular parallax principle of human eye, and binocular receives left visual point image from Same Scene and right visual point image independently of one another, is merged and forms binocular parallax, thus enjoy the stereo-picture with depth perception and realism by brain.Compared with single channel image, stereo-picture needs the picture quality simultaneously ensureing two passages, therefore carries out quality assessment to it and has very important significance.But current stereoscopic image quality lacks effective method for objectively evaluating and evaluates.Therefore, set up effective stereo image quality objective evaluation model tool to be of great significance.
Owing to affecting the many factors of stereo image quality, as left viewpoint and right viewpoint quality distortion situation, stereoscopic sensation are known the inside story condition, observer's visual fatigue etc., therefore how effectively carrying out stereo image quality evaluation is the difficulties needing solution badly.Existing method carrys out prediction and evaluation model by machine learning at present, but its computation complexity is higher, and training pattern needs the subjective assessment value predicting each evaluation map picture, and be not suitable for actual application scenario, has some limitations.Signal decomposes by rarefaction representation on known collection of functions, makes every effort to approach original signal with few basis function of trying one's best on transform domain.A key issue of rarefaction representation is exactly how effectively to construct the essential characteristic that dictionary carrys out token image.The dictionary construction algorithm proposed at present comprises: 1) have the dictionary construction method of learning process: trained obtaining dictionary information, as support vector machine etc. by machine learning; 2) without the dictionary construction method of learning process: directly utilize the feature of image to construct dictionary, as multiple dimensioned Gabor dictionary, multiple dimensioned Gauss's dictionary etc.Therefore, the dictionary how carried out without learning process constructs, and how to carry out quality estimation according to dictionary, and from dictionary, how to extract the visual signature of reflection eyefidelity, be all the technical matters needing emphasis to solve in stereo image quality evaluation study.
Summary of the invention
Technical matters to be solved by this invention is to provide the objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity, and its computation complexity is low, and effectively can improve the correlativity between objective evaluation result and subjective perception.
The present invention solves the problems of the technologies described above adopted technical scheme: the objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity, it is characterized in that comprising training stage and test phase two processes, and the described training stage comprises the following steps:
-1 1., choose N original undistorted stereo-picture composing training image set, be designated as { S i, org| 1≤i≤N}, wherein, N>1, S i, orgrepresent { S i, org| i-th in 1≤i≤N} original undistorted stereo-picture;
-2 1., utilize Region detection algorithms, judge { S i, org| each pixel in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image belongs to occlusion area and still belongs to matching area;
-3 1., adopt Gabor filter, obtain { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image;
Then according to { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture, obtains { S i, org| the amplitude of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture;
Equally, according to { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the right visual point image of every in 1≤i≤N} original undistorted stereo-picture, obtains { S i, org| the amplitude of each pixel under different center frequency and the different directions factor in the right visual point image of every in 1≤i≤N} original undistorted stereo-picture;
Further, according to { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, obtains { S i, org| the amplitude of each pixel under different center frequency, the skew of different directions Summing Factor out of phase in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image;
1.-4, to { S i, org| left visual point image and the right visual point image of every in 1≤i≤N} original undistorted stereo-picture carry out non-overlapped point sub-block process;
Then K-SVD method is adopted, to by { S i, org| dictionary training and operation is carried out in the proper vector set that all sub-blocks proper vector separately belonging to occlusion area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image is formed, and obtains { S i, org| the monocular vision dictionary table of 1≤i≤N}, is designated as D nc, wherein, the initial value of j is total number that 1, K represents the dictionary of setting, K>=1, represent D ncin a jth visual dictionary, any one sub-block belonging to occlusion area is have the pixel belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of occlusion area is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
Equally, adopt K-SVD method, to by { S i, org| dictionary training and operation is carried out in the proper vector set that all sub-blocks proper vector separately belonging to matching area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image is formed, and obtains { S i, org| the binocular vision dictionary table of 1≤i≤N}, is designated as D bf, wherein, the initial value of j is total number that 1, K represents the dictionary of setting, K>=1, represent D bfin a jth visual dictionary, any one sub-block belonging to matching area is the pixel not belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of matching area is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
Described test phase comprises the following steps:
2. for any one secondary test stereo-picture S test, by S testcorresponding original undistorted stereo-picture is designated as S org;
According to step 1.-2 to step 1.-3 process, with identical operation obtain S testand S orgthe amplitude of each pixel under different center frequency and the different directions factor in respective left visual point image and right visual point image, and obtain S testand S orgthe amplitude of each pixel under different center frequency, the skew of different directions Summing Factor out of phase in respective left visual point image and right visual point image;
By S testleft visual point image and right visual point image in belong to occlusion area all sub-blocks proper vector separately form a proper vector set, by S orgleft visual point image and right visual point image in belong to occlusion area all sub-blocks proper vector separately form a proper vector set, any one sub-block belonging to occlusion area is have the pixel belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of occlusion area is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block; By S testleft visual point image and right visual point image in belong to all sub-blocks of matching area proper vector form a proper vector set, by S orgleft visual point image and right visual point image in belong to all sub-blocks of matching area proper vector form a proper vector set, any one sub-block belonging to matching area is the pixel not belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of matching area is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
According to { the S that the training stage obtains i, org| the monocular vision dictionary table D of 1≤i≤N} nc, the sparse coefficient matrix of each proper vector in two proper vector set that acquisition occlusion area is correlated with; And { the S obtained according to the training stage i, org| the binocular vision dictionary table D of 1≤i≤N} bf, the sparse coefficient matrix of each proper vector in two proper vector set that acquisition matching area is correlated with;
Two the proper vectors sparse coefficient matrix separately corresponding according to position in two proper vector set that occlusion area is correlated with, obtains S testleft visual point image and right visual point image in the local objective evaluation metric of corresponding sub-block; And two proper vectors sparse coefficient matrix separately that in two proper vector set of being correlated with according to matching area, position is corresponding, obtain S testleft visual point image and right visual point image in the local objective evaluation metric of corresponding sub-block;
According to S testleft visual point image and right visual point image in belong to local objective evaluation metric and the S of each sub-block of occlusion area testleft visual point image and right visual point image in belong to the local objective evaluation metric of each sub-block of matching area, obtain S testpicture quality objective evaluation predicted value.
The detailed process of the Region detection algorithms of described step 1. in-2 is:
A1, by { S i, org| current pending i-th original undistorted stereo-picture S in 1≤i≤N} i, orgbe defined as current stereo-picture, by current stereo-picture S i, orgleft visual point image be defined as when front left visual point image, by current stereo-picture S i, orgright visual point image be defined as when front right visual point image, wherein, the initial value of i is 1;
A2, the anaglyph adopting Block Matching Algorithm calculating to work as front left visual point image and work as between front right visual point image, be designated as { d i, org(x, y) }, wherein, 1≤x≤W, 1≤y≤H, W represents { S i, org| the width of the original undistorted stereo-picture in 1≤i≤N}, H represents { S i, org| the height of the original undistorted stereo-picture in 1≤i≤N}, d i, org(x, y) represents { d i, org(x, y) } in coordinate position be the pixel value of the pixel of (x, y);
A3, basis { d i, org(x, y) } in the pixel value of each pixel, judge still to belong to matching area when each pixel in front left visual point image belongs to occlusion area; For being the pixel of (x, y) when coordinate position in front left visual point image, if d i, org(x, y)=255, then judge when coordinate position in front left visual point image belongs to occlusion area, if d as the pixel of (x, y) i, org(x, y) ≠ 255, then judge when coordinate position in front left visual point image belongs to matching area as the pixel of (x, y);
A4, when in front right visual point image, the pixel corresponding with when each pixel belonging to matching area in front left visual point image is judged to belong to matching area; Then be judged to belong to occlusion area by when all pixels in front right visual point image except belonging to matching area;
A5, make i=i+1, by { S i, org| in 1≤i≤N}, next pending original undistorted stereo-picture is as current stereo-picture, using the left visual point image of current stereo-picture as working as front left visual point image, using the right visual point image of current stereo-picture as working as front right visual point image, then return step a2 to continue to perform, until { S i, org| till all original undistorted stereo-picture in 1≤i≤N} is disposed, wherein, "=" in i=i+1 is assignment.
Described step 1.-3 detailed process be:
B1, by { S i, org| current pending i-th original undistorted stereo-picture S in 1≤i≤N} i, orgbe defined as current stereo-picture, by current stereo-picture S i, orgleft visual point image be defined as when front left visual point image, by current stereo-picture S i, orgright visual point image be defined as when front right visual point image, wherein, the initial value of i is 1;
B2, employing Gabor filter carry out filtering process to when front left visual point image, obtain when the frequency response of each pixel under different center frequency and the different directions factor in front left visual point image, be that the pixel of (x, y) is designated as in the centre frequency frequency response that to be ω and direction factor be under θ by working as coordinate position in front left visual point image
Equally, Gabor filter is adopted to carry out filtering process to when front right visual point image, obtain when the frequency response of each pixel under different center frequency and the different directions factor in front right visual point image, be that the pixel of (x, y) is designated as in the centre frequency frequency response that to be ω and direction factor be under θ by working as coordinate position in front right visual point image G i , org R ( x , y ; ω , θ ) ;
Above-mentioned, 1≤x≤W, 1≤y≤H, W represents { S i, org| the width of the original undistorted stereo-picture in 1≤i≤N}, H represents { S i, org| the height of the original undistorted stereo-picture in 1≤i≤N}, ω represents the centre frequency of adopted Gabor filter, ω ∈ Ω ω, Ω ωrepresent the set of the centre frequency of the Gabor filter adopted, θ represents the direction factor of adopted Gabor filter, θ ∈ Ω θ, Ω θrepresent the set of the direction factor of the Gabor filter adopted;
B3, basis are when the frequency response of each pixel under different center frequency and the different directions factor in front left visual point image, calculate when the amplitude of each pixel under different center frequency and the different directions factor in front left visual point image, be that the pixel of (x, y) is designated as at the centre frequency amplitude that to be ω and direction factor be under θ by working as coordinate position in front left visual point image E i , org L ( x , y ; ω , θ ) = | | G i , org L ( x , y ; ω , θ ) | | 2 2 , Wherein, symbol " || || 2" for asking for the 2-norm sign of matrix;
Equally, according to the frequency response of each pixel under different center frequency and the different directions factor of working as in front right visual point image, calculate when the amplitude of each pixel under different center frequency and the different directions factor in front right visual point image, be that the pixel of (x, y) is designated as at the centre frequency amplitude that to be ω and direction factor be under θ by working as coordinate position in front right visual point image E i , org R ( x , y ; ω , θ ) = | | G i , org R ( x , y ; ω , θ ) | | 2 2 , Wherein, symbol " || || 2" for asking for the 2-norm sign of matrix;
B4, basis are when front left visual point image with when the frequency response of each pixel under different center frequency and the different directions factor in front right visual point image, calculate when front left visual point image with when the amplitude of each pixel in front right visual point image under different center frequency, the skew of different directions Summing Factor out of phase, by work as front left visual point image and when front right visual point image separately middle coordinate position be (x, y) pixel centre frequency be ω, the direction factor amplitude that to be θ and phase offset be under Δ ψ is designated as E i , org LR ( x , y ; ω , θ , Δψ ) = | | G i , org L ( x , y ; ω , θ ) + e jΔψ × G i , org R ( x , y ; ω , θ ) | | 2 2 , Wherein, Δ ψ ∈ Ω Δ ψ, Ω Δ ψrepresent the set of the phase offset of the Gabor filter adopted, symbol " || || 2" for asking for the 2-norm sign of matrix, e represents nature radix, j is imaginary unit;
B5, make i=i+1, by { S i, org| in 1≤i≤N}, next pending original undistorted stereo-picture is as current stereo-picture, using the left visual point image of current stereo-picture as working as front left visual point image, using the right visual point image of current stereo-picture as working as front right visual point image, then return step b2 to continue to perform, until { S i, org| till all original undistorted stereo-picture in 1≤i≤N} is disposed, wherein, "=" in i=i+1 is assignment.
Described step 1.-4 detailed process be:
C1, by { S i, org| left visual point image and the right visual point image of every in 1≤i≤N} original undistorted stereo-picture are divided into respectively individual size is the sub-block of the non-overlapping copies of 8 × 8, wherein, and W represents { S i, org| the width of the original undistorted stereo-picture in 1≤i≤N}, H represents { S i, org| the height of the original undistorted stereo-picture in 1≤i≤N};
C2, determine { S i, org| belong to all sub-blocks of occlusion area in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, for S i, orgleft visual point image and right visual point image in any one sub-block, if there is the pixel belonging to occlusion area in this sub-block, then determine that this sub-block belongs to occlusion area;
And by { S i, org| all sub-blocks in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image except the sub-block belonging to occlusion area are defined as belonging to matching area;
C3, acquisition { S i, org| belong to the proper vector of each sub-block of occlusion area in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, for S i, orgleft visual point image and right visual point image in belong to any one sub-block of occlusion area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
And obtain { S i, org| belong to the proper vector of each sub-block of matching area in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, for S i, orgleft visual point image and right visual point image in belong to any one sub-block of matching area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
C4, by { S i, org| all sub-blocks proper vector separately belonging to occlusion area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image forms a proper vector set, is designated as { y t| 1≤t≤M 1, wherein, y tfor { y t| 1≤t≤M 1in t proper vector, y tdimension be 64 × N ω× N θ, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, M 1represent { S i, org| belong to total number of the sub-block of occlusion area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image,
And by { S i, org| the proper vector belonging to all sub-blocks of matching area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image forms a proper vector set, is designated as { z t| 1≤t≤M 2, wherein, z tfor { z t| 1≤t≤M 2in t proper vector, z tdimension be 64 × N ω× N θ× N Δ ψ, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, N Δ ψrepresent total number of the phase offset of Gabor filter, M 2represent { S i, org| belong to total number of the sub-block of matching area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image, M 2 < W &times; H &times; N 64 ;
C5, employing K-SVD method are to { y t| 1≤t≤M 1carry out dictionary training and operation, obtain { y t| 1≤t≤M 1visual dictionary table, and by { y t| 1≤t≤M 1visual dictionary table as { S i, org| the monocular vision dictionary table of 1≤i≤N}, is designated as D nc, d ncsolved by K-SVD method obtain, constraint condition be: || x t|| 0≤ τ, wherein, D ncdimension be (64 × N ω× N θ) × K, K represents total number of the dictionary of setting, K>=1, represent D ncin a jth dictionary, min () for getting minimum value function, symbol " || || 2" for asking for the 2-norm sign of matrix, y ncdimension be (64 × N ω× N θ) × M 1, y 1represent { y t| 1≤t≤M 1in the 1st proper vector, y trepresent { y t| 1≤t≤M 1in t proper vector, represent { y t| 1≤t≤M 1in M 1individual proper vector, X ncrepresent sparse matrix, x ncdimension be K × M 1, x 1represent X ncin the 1st row, x trepresent X ncin t row, represent X ncin M 1row, symbol " [] " is vector representation symbol, represent existence t, symbol " || || 0" for asking for the 0-norm sign of matrix, τ is error coefficient;
And adopt K-SVD method to { z t| 1≤t≤M 2carry out dictionary training and operation, obtain { z t| 1≤t≤M 2visual dictionary table, and by { z t| 1≤t≤M 2visual dictionary table as { S i, org| the binocular vision dictionary table of 1≤i≤N}, is designated as D bf, d bfsolved by K-SVD method obtain, constraint condition be: || f t|| 0≤ τ, wherein, D bfdimension be (64 × N ω× N θ× N Δ ψ) × K, K represents total number of the dictionary of setting, K>=1, represent D bfin a jth dictionary, min () for getting minimum value function, symbol " || || 2" for asking for the 2-norm sign of matrix, z bfdimension be (64 × N ω× N θ× N Δ ψ) × M 2, z 1for { z t| 1≤t≤M 2in the 1st proper vector, z tfor { z t| 1≤t≤M 2in t proper vector, for { z t| 1≤t≤M 2in M 2individual proper vector, F bfrepresent sparse matrix, f bfdimension be K × M 2, f 1represent F bfin the 1st row, f trepresent F bfin t row, represent F bfin M 2row, symbol " [] " is vector representation symbol, represent existence t, symbol " || || 0" for asking for the 0-norm sign of matrix, τ is error coefficient.
τ=0.1 is got in described step c5.
Described step detailed process is 2.:
2.-1, by S testleft visual point image be designated as L test, by S testright visual point image be designated as R test, by S testcorresponding original undistorted stereo-picture is designated as S org, by S orgleft visual point image be designated as L org, by S orgright visual point image be designated as R org;
-2 2., according to step 1.-2 process, judge L with identical operation testand R testin each pixel belong to occlusion area and still belong to matching area, and judge L organd R orgin each pixel belong to occlusion area and still belong to matching area;
-3 2., according to step 1.-3 process, obtain L with identical operation testin amplitude, the R of each pixel under different center frequency and the different directions factor testin amplitude, the L of each pixel under different center frequency and the different directions factor testand R testin the amplitude of each pixel under different center frequency, the skew of different directions Summing Factor out of phase, and obtain L orgin amplitude, the R of each pixel under different center frequency and the different directions factor orgin amplitude, the L of each pixel under different center frequency and the different directions factor organd R orgin each pixel different center frequency, different directions Summing Factor out of phase skew under amplitude;
2.-4, to L testand R testand L organd R orgcarry out non-overlapped point sub-block process respectively;
Then L is determined testand R testand L organd R orgin belong to all sub-blocks of occlusion area, for L testand R testand L organd R orgin any one sub-block, if there is the pixel belonging to occlusion area in this sub-block, then determine that this sub-block belongs to occlusion area; And by L testand R testand L organd R orgin all sub-blocks except the sub-block belonging to occlusion area be defined as belonging to matching area;
Then L is obtained testand R testand L organd R orgin belong to the proper vector of each sub-block of occlusion area, for L testand R testand L organd R orgin belong to any one sub-block of occlusion area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block; And obtain L testand R testand L organd R orgin belong to the proper vector of each sub-block of matching area, for L testand R testand L organd R orgin belong to any one sub-block of matching area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
Afterwards by L testand R testin belong to occlusion area all sub-blocks proper vector separately form a proper vector set, be designated as { y t', test| 1≤t'≤M 1', and by L testand R testin belong to all sub-blocks of matching area proper vector form a proper vector set, be designated as { z t', test| 1≤t'≤M 2', wherein, y t', testfor { y t', test| 1≤t'≤M 1' in t' proper vector, y t', testdimension be 64 × N ω× N θ, at this M 1' represent L testand R testin belong to total number of the sub-block of occlusion area, z t', testfor { z t', test| 1≤t'≤M 2' in t' proper vector, z t', testdimension be 64 × N ω× N θ× N Δ ψ, at this M 2' represent L testand R testin belong to total number of the sub-block of matching area, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, N Δ ψrepresent total number of the phase offset of Gabor filter;
Equally, by L organd R orgin belong to occlusion area all sub-blocks proper vector separately form a proper vector set, be designated as { y t', org| 1≤t'≤M 1', and by L organd R orgin belong to all sub-blocks of matching area proper vector form a proper vector set, be designated as { z t', org| 1≤t'≤M 2', wherein, y t', orgfor { y t', org| 1≤t'≤M 1' in t' proper vector, y t', orgdimension be 64 × N ω× N θ, at this M 1' represent L organd R orgin belong to total number of the sub-block of occlusion area, z t', orgfor { z t', org| 1≤t'≤M 2' in t' proper vector, z t', orgdimension be 64 × N ω× N θ× N Δ ψ, at this M 2' represent L organd R orgin belong to total number of the sub-block of matching area, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, N Δ ψrepresent total number of the phase offset of Gabor filter;
2.-5, according to { the S that the training stage obtains i, org| the monocular vision dictionary table D of 1≤i≤N} nc, obtain { y t', test| 1≤t'≤M 1' in the sparse coefficient matrix of each proper vector and { y t', org| 1≤t'≤M 1' in the sparse coefficient matrix of each proper vector, by y t', testsparse coefficient matrix be designated as x t', test, x t', test=(D nc) -1y t', test, by y t', orgsparse coefficient matrix be designated as x t', org, x t', org=(D nc) -1y t', org, wherein, (D nc) -1for D ncinverse matrix;
According to { the S that the training stage obtains i, org| the binocular vision dictionary table D of 1≤i≤N} bf, obtain { z t', test| 1≤t'≤M 2' in the sparse coefficient matrix of each proper vector and { z t', org| 1≤t'≤M 2' in the sparse coefficient matrix of each proper vector, by z t', testsparse coefficient matrix be designated as f t', test, f t', test=(D bf) -1z t', test, by z t', orgsparse coefficient matrix be designated as f t', org, f t', org=(D bf) -1z t', org, wherein, (D bf) -1for D bfinverse matrix;
2.-6, L is calculated testand R testin belong to the local objective evaluation metric of each sub-block of occlusion area, by L testand R testin the local objective evaluation metric of t' sub-block that belongs in all sub-blocks of occlusion area be designated as q t', test, wherein, (x t', test) tfor x t', testtransposed matrix, symbol " || || 2" for asking for the 2-norm sign of matrix, C is controling parameters;
And calculate L testand R testin belong to the local objective evaluation metric of each sub-block of matching area, by L testand R testin belong to t' sub-block of matching area local objective evaluation metric be designated as p t', test, wherein, (f t', test) tfor f t', testtransposed matrix, symbol " || || 2" for asking for the 2-norm sign of matrix, C is controling parameters;
2.-7, S is calculated testmonocular image Objective Quality Assessment predicted value, be designated as and calculate S testbinocular image Objective Quality Assessment predicted value, be designated as
2.-8, S is calculated testpicture quality objective evaluation predicted value, be designated as Q, Q=w nc× Q nc+ (1-w nc) × Q bf, wherein, w ncfor Q ncweights proportion.
2. described step gets C=0.02 in-6.
2. described step gets w in-8 nc=0.2.
Compared with prior art, the invention has the advantages that:
1) the inventive method is in the training stage, obtained in undistorted stereo-picture by method for detecting area and belong to the pixel of occlusion area and belong to the pixel of matching area, and by unsupervised learning mode to training plan image set structure monocular vision dictionary table and binocular vision dictionary table, computation vision dictionary table is not more needed at test phase, this avoid complicated machine learning training process, reduce computation complexity.
2) the inventive method is at test phase, according to the monocular vision dictionary table constructed and binocular vision dictionary table, the sparse coefficient matrix of each sub-block of occlusion area and matching area is belonged in the test stereo-picture of distortion estimator and the undistorted stereo-picture of its correspondence, estimate that the sparse coefficient matrix obtained can reflect eyefidelity characteristic well according to monocular vision dictionary table and binocular vision dictionary table, and calculate monocular image Objective Quality Assessment predicted value and binocular image Objective Quality Assessment predicted value by sparse coefficient matrix, the picture quality objective evaluation predicted value obtained and subjective assessment value maintain good consistance.
Accompanying drawing explanation
Fig. 1 be the inventive method totally realize block diagram;
Fig. 2 is that the picture quality objective evaluation predicted value of every width distortion stereo-picture in the University Of Ningbo's stereo-picture storehouse utilizing the inventive method to obtain and mean subjective are marked the scatter diagram of difference;
Fig. 3 is that the picture quality objective evaluation predicted value of every width distortion stereo-picture in the LIVE stereo-picture storehouse utilizing the inventive method to obtain and mean subjective are marked the scatter diagram of difference.
Embodiment
Below in conjunction with accompanying drawing embodiment, the present invention is described in further detail.
The objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity that the present invention proposes, it totally realizes block diagram as shown in Figure 1, and it comprises training stage and test phase two processes, and the training stage comprises the following steps:
-1 1., choose N original undistorted stereo-picture composing training image set, be designated as { S i, org| 1≤i≤N}, wherein, N>1, S i, orgrepresent { S i, org| i-th in 1≤i≤N} original undistorted stereo-picture, symbol " { } " is set expression symbol.
In the specific implementation, the width number that original undistorted stereo-picture is chosen should be suitable, if the value of N is larger, then by training the precision of the visual dictionary table obtained also higher, but computation complexity is also higher, therefore gets N=10 in the present embodiment.
-2 1., utilize Region detection algorithms, judge { S i, org| each pixel in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image belongs to occlusion area and still belongs to matching area.
In this particular embodiment, the detailed process of the Region detection algorithms of step 1. in-2 is:
A1, by { S i, org| current pending i-th original undistorted stereo-picture S in 1≤i≤N} i, orgbe defined as current stereo-picture, by current stereo-picture S i, orgleft visual point image be defined as when front left visual point image, by current stereo-picture S i, orgright visual point image be defined as when front right visual point image, wherein, the initial value of i is 1.
A2, the anaglyph adopting the calculating of existing Block Matching Algorithm to work as front left visual point image and work as between front right visual point image, be designated as { d i, org(x, y) }, wherein, 1≤x≤W, 1≤y≤H, W represents { S i, org| the width of the original undistorted stereo-picture in 1≤i≤N}, H represents { S i, org| the height of the original undistorted stereo-picture in 1≤i≤N}, d i, org(x, y) represents { d i, org(x, y) } in coordinate position be the pixel value of the pixel of (x, y).
A3, basis { d i, org(x, y) } in the pixel value of each pixel, judge still to belong to matching area when each pixel in front left visual point image belongs to occlusion area; For being the pixel of (x, y) when coordinate position in front left visual point image, if d i, org(x, y)=255, then judge when coordinate position in front left visual point image belongs to occlusion area, if d as the pixel of (x, y) i, org(x, y) ≠ 255, then judge when coordinate position in front left visual point image belongs to matching area as the pixel of (x, y).
A4, when in front right visual point image, the pixel corresponding with when each pixel belonging to matching area in front left visual point image is judged to belong to matching area; Then be judged to belong to occlusion area by when all pixels in front right visual point image except belonging to matching area.
A5, make i=i+1, by { S i, org| in 1≤i≤N}, next pending original undistorted stereo-picture is as current stereo-picture, using the left visual point image of current stereo-picture as working as front left visual point image, using the right visual point image of current stereo-picture as working as front right visual point image, then return step a2 to continue to perform, until { S i, org| till all original undistorted stereo-picture in 1≤i≤N} is disposed, wherein, "=" in i=i+1 is assignment.
-3 1., adopt Gabor filter, obtain { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image.Then according to { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture, obtains { S i, org| the amplitude of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture.Equally, according to { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the right visual point image of every in 1≤i≤N} original undistorted stereo-picture, obtains { S i, org| the amplitude of each pixel under different center frequency and the different directions factor in the right visual point image of every in 1≤i≤N} original undistorted stereo-picture.Further, according to { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, obtains { S i, org| the amplitude of each pixel under different center frequency, the skew of different directions Summing Factor out of phase in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image.
In this particular embodiment, step 1.-3 detailed process be:
B1, by { S i, org| current pending i-th original undistorted stereo-picture S in 1≤i≤N} i, orgbe defined as current stereo-picture, by current stereo-picture S i, orgleft visual point image be defined as when front left visual point image, by current stereo-picture S i, orgright visual point image be defined as when front right visual point image, wherein, the initial value of i is 1.
B2, employing Gabor filter carry out filtering process to when front left visual point image, obtain when the frequency response of each pixel under different center frequency and the different directions factor in front left visual point image, be that the pixel of (x, y) is designated as in the centre frequency frequency response that to be ω and direction factor be under θ by working as coordinate position in front left visual point image G i , org L ( x , y ; &omega; , &theta; ) = e i , org L ( x , y ; &omega; , &theta; ) + jo i , org L ( x , y ; &omega; , &theta; ) . Equally, Gabor filter is adopted to carry out filtering process to when front right visual point image, obtain when the frequency response of each pixel under different center frequency and the different directions factor in front right visual point image, be that the pixel of (x, y) is designated as in the centre frequency frequency response that to be ω and direction factor be under θ by working as coordinate position in front right visual point image G i , org R ( x , y ; &omega; , &theta; ) = e i , org R ( x , y ; &omega; , &theta; ) + jo i , org R ( x , y ; &omega; , &theta; ) . Above-mentioned, 1≤x≤W, 1≤y≤H, W represents { S i, org| the width of the original undistorted stereo-picture in 1≤i≤N}, H represents { S i, org| the height of the original undistorted stereo-picture in 1≤i≤N}, ω represents the centre frequency of adopted Gabor filter, ω ∈ Ω ω, Ω ωrepresent the set of the centre frequency of the Gabor filter adopted, Ω ω={ 1.74,2.47,3.49,4.93,6.98}, θ represent the direction factor of adopted Gabor filter, θ ∈ Ω θ, Ω θrepresent the set of the direction factor of the Gabor filter adopted, &Omega; &theta; = { 0 , &pi; 4 , &pi; 2 , 3 &pi; 4 , &pi; , 5 &pi; 4 , 3 &pi; 2 , 7 &pi; 4 } , for real part, for imaginary part, for real part, for imaginary part, j is imaginary unit.
B3, basis are when the frequency response of each pixel under different center frequency and the different directions factor in front left visual point image, calculate when the amplitude of each pixel under different center frequency and the different directions factor in front left visual point image, be that the pixel of (x, y) is designated as at the centre frequency amplitude that to be ω and direction factor be under θ by working as coordinate position in front left visual point image E i , org L ( x , y ; &omega; , &theta; ) = | | G i , org L ( x , y ; &omega; , &theta; ) | | 2 2 , Wherein, symbol " || || 2" for asking for the 2-norm sign of matrix.Equally, according to the frequency response of each pixel under different center frequency and the different directions factor of working as in front right visual point image, calculate when the amplitude of each pixel under different center frequency and the different directions factor in front right visual point image, be that the pixel of (x, y) is designated as at the centre frequency amplitude that to be ω and direction factor be under θ by working as coordinate position in front right visual point image E i , org R ( x , y ; &omega; , &theta; ) = | | G i , org R ( x , y ; &omega; , &theta; ) | | 2 2 , Wherein, symbol " || || 2" for asking for the 2-norm sign of matrix.
B4, basis are when front left visual point image with when the frequency response of each pixel under different center frequency and the different directions factor in front right visual point image, calculate when front left visual point image with when the amplitude of each pixel in front right visual point image under different center frequency, the skew of different directions Summing Factor out of phase, by work as front left visual point image and when front right visual point image separately middle coordinate position be (x, y) pixel centre frequency be ω, the direction factor amplitude that to be θ and phase offset be under Δ ψ is designated as E i , org LR ( x , y ; &omega; , &theta; , &Delta;&psi; ) = | | G i , org L ( x , y ; &omega; , &theta; ) + e j&Delta;&psi; &times; G i , org R ( x , y ; &omega; , &theta; ) | | 2 2 , Wherein, Δ ψ ∈ Ω Δ ψ, Ω Δ ψrepresent the set of the phase offset of the Gabor filter adopted, &Omega; &Delta;&psi; = { - &pi; , - 7 &pi; 8 , - 3 &pi; 4 , - 5 &pi; 8 , - &pi; 2 , - 3 &pi; 8 , - &pi; 4 , - &pi; 8 , 0 } , Symbol " || || 2" for asking for the 2-norm sign of matrix, e represents nature radix, j is imaginary unit.
B5, make i=i+1, by { S i, org| in 1≤i≤N}, next pending original undistorted stereo-picture is as current stereo-picture, using the left visual point image of current stereo-picture as working as front left visual point image, using the right visual point image of current stereo-picture as working as front right visual point image, then return step b2 to continue to perform, until { S i, org| till all original undistorted stereo-picture in 1≤i≤N} is disposed, wherein, "=" in i=i+1 is assignment.
1.-4, to { S i, org| left visual point image and the right visual point image of every in 1≤i≤N} original undistorted stereo-picture carry out non-overlapped point sub-block process.Then K-SVD method is adopted, to by { S i, org| dictionary training and operation is carried out in the proper vector set that all sub-blocks proper vector separately belonging to occlusion area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image is formed, and obtains { S i, org| the monocular vision dictionary table of 1≤i≤N}, is designated as D nc, wherein, the initial value of j is total number that 1, K represents the dictionary of setting, K>=1, represent D ncin a jth visual dictionary, any one sub-block belonging to occlusion area is have the pixel belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of occlusion area is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block.Equally, adopt K-SVD method, to by { S i, org| dictionary training and operation is carried out in the proper vector set that all sub-blocks proper vector separately belonging to matching area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image is formed, and obtains { S i, org| the binocular vision dictionary table of 1≤i≤N}, is designated as D bf, wherein, the initial value of j is total number that 1, K represents the dictionary of setting, K>=1, represent D bfin a jth visual dictionary, any one sub-block belonging to matching area is the pixel not belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of matching area is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block.
At this, the value due to K is excessive there will be cluster phenomenon, and the value of K is too small there will be deficient cluster phenomenon, therefore gets K=128 in the present embodiment.
In this particular embodiment, step 1.-4 detailed process be:
C1, by { S i, org| left visual point image and the right visual point image of every in 1≤i≤N} original undistorted stereo-picture are divided into respectively individual size is the sub-block of the non-overlapping copies of 8 × 8, wherein, and W represents { S i, org| the width of the original undistorted stereo-picture in 1≤i≤N}, H represents { S i, org| the height of the original undistorted stereo-picture in 1≤i≤N}.
C2, determine { S i, org| belong to all sub-blocks of occlusion area in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, for S i, orgleft visual point image and right visual point image in any one sub-block, if there is the pixel belonging to occlusion area in this sub-block, then determine that this sub-block belongs to occlusion area.
And by { S i, org| all sub-blocks in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image except the sub-block belonging to occlusion area are defined as belonging to matching area.
C3, acquisition { S i, org| belong to the proper vector of each sub-block of occlusion area in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, for S i, orgleft visual point image and right visual point image in belong to any one sub-block of occlusion area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block.
And obtain { S i, org| belong to the proper vector of each sub-block of matching area in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, for S i, orgleft visual point image and right visual point image in belong to any one sub-block of matching area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block.
C4, by { S i, org| all sub-blocks proper vector separately belonging to occlusion area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image forms a proper vector set, is designated as { y t| 1≤t≤M 1, wherein, y tfor { y t| 1≤t≤M 1in t proper vector, y tdimension be 64 × N ω× N θ, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, N in the present embodiment ω=5, N θ=8, M 1represent { S i, org| belong to total number of the sub-block of occlusion area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image, M 1 < W &times; H &times; N 64 .
And by { S i, org| the proper vector belonging to all sub-blocks of matching area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image forms a proper vector set, is designated as { z t| 1≤t≤M 2, wherein, z tfor { z t| 1≤t≤M 2in t proper vector, z tdimension be 64 × N ω× N θ× N Δ ψ, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, N Δ ψrepresent total number of the phase offset of Gabor filter, N in the present embodiment ω=5, N θ=8, N Δ ψ=9, M 2represent { S i, org| belong to total number of the sub-block of matching area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image,
C5, employing K-SVD method are to { y t| 1≤t≤M 1carry out dictionary training and operation, obtain { y t| 1≤t≤M 1visual dictionary table, and by { y t| 1≤t≤M 1visual dictionary table as { S i, org| the monocular vision dictionary table of 1≤i≤N}, is designated as D nc, d ncsolved by K-SVD method obtain, constraint condition be: || x t|| 0≤ τ, wherein, D ncdimension be (64 × N ω× N θ) × K, K represents total number of the dictionary of setting, K>=1, represent D ncin a jth dictionary, min () for getting minimum value function, symbol " || || 2" for asking for the 2-norm sign of matrix, y ncdimension be (64 × N ω× N θ) × M 1, y 1represent { y t| 1≤t≤M 1in the 1st proper vector, y trepresent { y t| 1≤t≤M 1in t proper vector, represent { y t| 1≤t≤M 1in M 1individual proper vector, X ncrepresent sparse matrix, x ncdimension be K × M 1, x 1represent X ncin the 1st row, x trepresent X ncin t row, represent X ncin M 1row, symbol " [] " is vector representation symbol, represent existence t, symbol " || || 0" for asking for the 0-norm sign of matrix, τ is error coefficient, gets τ=0.1 in the present embodiment.
And adopt K-SVD method to { z t| 1≤t≤M 2carry out dictionary training and operation, obtain { z t| 1≤t≤M 2visual dictionary table, and by { z t| 1≤t≤M 2visual dictionary table as { S i, org| the binocular vision dictionary table of 1≤i≤N}, is designated as D bf, d bfsolved by K-SVD method obtain, constraint condition be: || f t|| 0≤ τ, wherein, D bfdimension be (64 × N ω× N θ× N Δ ψ) × K, K represents total number of the dictionary of setting, K>=1, represent D bfin a jth dictionary, min () for getting minimum value function, symbol " || || 2" for asking for the 2-norm sign of matrix, z bfdimension be (64 × N ω× N θ× N Δ ψ) × M 2, z 1for { z t| 1≤t≤M 2in the 1st proper vector, z tfor { z t| 1≤t≤M 2in t proper vector, for { z t| 1≤t≤M 2in M 2individual proper vector, F bfrepresent sparse matrix, f bfdimension be K × M 2, f 1represent F bfin the 1st row, f trepresent F bfin t row, represent F bfin M 2row, symbol " [] " is vector representation symbol, represent existence t, symbol " || || 0" for asking for the 0-norm sign of matrix, τ is error coefficient, gets τ=0.1 in the present embodiment.
Test phase comprises the following steps:
2. for the distortion stereo-picture S of any one secondary test test, by S testcorresponding original undistorted stereo-picture is designated as S org.According to step 1.-2 to step 1.-3 process, with identical operation obtain S testand S orgthe amplitude of each pixel under different center frequency and the different directions factor in respective left visual point image and right visual point image, and obtain S testand S orgthe amplitude of each pixel under different center frequency, the skew of different directions Summing Factor out of phase in respective left visual point image and right visual point image.By S testleft visual point image and right visual point image in belong to occlusion area all sub-blocks proper vector separately form a proper vector set, by S orgleft visual point image and right visual point image in belong to occlusion area all sub-blocks proper vector separately form a proper vector set, any one sub-block belonging to occlusion area is have the pixel belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of occlusion area is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block; By S testleft visual point image and right visual point image in belong to all sub-blocks of matching area proper vector form a proper vector set, by S orgleft visual point image and right visual point image in belong to all sub-blocks of matching area proper vector form a proper vector set, any one sub-block belonging to matching area is the pixel not belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of matching area is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block.According to { the S that the training stage obtains i, org| the monocular vision dictionary table D of 1≤i≤N} nc, the sparse coefficient matrix of each proper vector in two proper vector set that acquisition occlusion area is correlated with; And { the S obtained according to the training stage i, org| the binocular vision dictionary table D of 1≤i≤N} bf, the sparse coefficient matrix of each proper vector in two proper vector set that acquisition matching area is correlated with.Two the proper vectors sparse coefficient matrix separately corresponding according to position in two proper vector set that occlusion area is correlated with, obtains S testleft visual point image and right visual point image in the local objective evaluation metric of corresponding sub-block; And two proper vectors sparse coefficient matrix separately that in two proper vector set of being correlated with according to matching area, position is corresponding, obtain S testleft visual point image and right visual point image in the local objective evaluation metric of corresponding sub-block.According to S testleft visual point image and right visual point image in belong to local objective evaluation metric and the S of each sub-block of occlusion area testleft visual point image and right visual point image in belong to the local objective evaluation metric of each sub-block of matching area, obtain S testpicture quality objective evaluation predicted value.
In this particular embodiment, step detailed process is 2.:
2.-1, by S testleft visual point image be designated as L test, by S testright visual point image be designated as R test, by S testcorresponding original undistorted stereo-picture is designated as S org, by S orgleft visual point image be designated as L org, by S orgright visual point image be designated as R org.
-2 2., according to step 1.-2 process, judge L with identical operation testand R testin each pixel belong to occlusion area and still belong to matching area, and judge L organd R orgin each pixel belong to occlusion area and still belong to matching area.With L testand R testfor example, judge L testand R testin each pixel belong to the detailed process that occlusion area still belongs to matching area and be: calculate L testwith R testbetween anaglyph, be designated as { d test(x, y) }, d test(x, y) represents { d test(x, y) } in coordinate position be the pixel value of the pixel of (x, y); For L testmiddle coordinate position is the pixel of (x, y), if d test(x, y)=255, then judge L testmiddle coordinate position is that the pixel of (x, y) belongs to occlusion area, if d test(x, y) ≠ 255, then judge L testmiddle coordinate position is that the pixel of (x, y) belongs to matching area; At R testin, will with L testin belong to each pixel of matching area corresponding pixel be judged to belong to matching area, by R testin all pixels except belonging to matching area be judged to belong to occlusion area.
-3 2., according to step 1.-3 process, obtain L with identical operation testin amplitude, the R of each pixel under different center frequency and the different directions factor testin amplitude, the L of each pixel under different center frequency and the different directions factor testand R testin the amplitude of each pixel under different center frequency, the skew of different directions Summing Factor out of phase, and obtain L orgin amplitude, the R of each pixel under different center frequency and the different directions factor orgin amplitude, the L of each pixel under different center frequency and the different directions factor organd R orgin each pixel different center frequency, different directions Summing Factor out of phase skew under amplitude.With L testand R testfor example, the detailed process obtaining the amplitude of pixel is: adopt Gabor filter to L testand R testcarry out filtering process respectively, correspondence obtains L testand R testin the frequency response of each pixel under different center frequency and the different directions factor; Calculate L testin the amplitude of each pixel under different center frequency and the different directions factor, by L testmiddle coordinate position is that the pixel of (x, y) is designated as at the centre frequency amplitude that to be ω and direction factor be under θ E test L ( x , y ; &omega; , &theta; ) = | | G test L ( x , y ; &omega; , &theta; ) | | 2 2 , represent L testmiddle coordinate position is the pixel of (x, y) be ω and direction factor be θ in centre frequency under frequency response; Calculate R testin the amplitude of each pixel under different center frequency and the different directions factor, by R testmiddle coordinate position is that the pixel of (x, y) is designated as at the centre frequency amplitude that to be ω and direction factor be under θ E test R ( x , y ; &omega; , &theta; ) = | | G test R ( x , y ; &omega; , &theta; ) | | 2 2 , represent R testmiddle coordinate position is the pixel of (x, y) be ω and direction factor be θ in centre frequency under frequency response; Calculate L testand R testin each pixel different center frequency, different directions Summing Factor out of phase skew under amplitude, by L testand R testmiddle coordinate position be (x, y) pixel centre frequency be ω, direction factor be θ and phase offset be Δ ψ under amplitude correspondence be designated as E test LR ( x , y ; &omega; , &theta; , &Delta;&psi; ) = | | G test L ( x , y ; &omega; , &theta; ) + e j&Delta;&psi; &times; G test R ( x , y ; &omega; , &theta; ) | | 2 2 .
2.-4, to L testand R testand L organd R orgcarry out non-overlapped point sub-block process respectively, by L testand R testand L organd R orgbe divided into respectively individual size is the sub-block of the non-overlapping copies of 8 × 8, S testsize consistent with the size of the undistorted stereo-picture selected by the training stage.Then L is determined testand R testand L organd R orgin belong to all sub-blocks of occlusion area, for L testand R testand L organd R orgin any one sub-block, if there is the pixel belonging to occlusion area in this sub-block, then determine that this sub-block belongs to occlusion area; And by L testand R testand L organd R orgin all sub-blocks except the sub-block belonging to occlusion area be defined as belonging to matching area.Then L is obtained testand R testand L organd R orgin belong to the proper vector of each sub-block of occlusion area, for L testand R testand L organd R orgin belong to any one sub-block of occlusion area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block; And obtain L testand R testand L organd R orgin belong to the proper vector of each sub-block of matching area, for L testand R testand L organd R orgin belong to any one sub-block of matching area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block.Afterwards by L testand R testin belong to occlusion area all sub-blocks proper vector separately form a proper vector set, be designated as { y t', test| 1≤t'≤M 1', and by L testand R testin belong to all sub-blocks of matching area proper vector form a proper vector set, be designated as { z t', test| 1≤t'≤M 2', wherein, y t', testfor { y t', test| 1≤t'≤M 1' in t' proper vector, y t', testdimension be 64 × N ω× N θ, at this M 1' represent L testand R testin belong to total number of the sub-block of occlusion area, z t', testfor { z t', test| 1≤t'≤M 2' in t' proper vector, z t', testdimension be 64 × N ω× N θ× N Δ ψ, at this M 2' represent L testand R testin belong to total number of the sub-block of matching area, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, N Δ ψrepresent total number of the phase offset of Gabor filter, N in the present embodiment ω=5, N θ=8, N Δ ψ=9.Equally, by L organd R orgin belong to occlusion area all sub-blocks proper vector separately form a proper vector set, be designated as { y t', org| 1≤t'≤M 1', and by L organd R orgin belong to all sub-blocks of matching area proper vector form a proper vector set, be designated as { z t', org| 1≤t'≤M 2', wherein, y t', orgfor { y t', org| 1≤t'≤M 1' in t' proper vector, y t', orgdimension be 64 × N ω× N θ, at this M 1' represent L organd R orgin belong to total number of the sub-block of occlusion area, z t', orgfor { z t', org| 1≤t'≤M 2' in t' proper vector, z t', orgdimension be 64 × N ω× N θ× N Δ ψ, at this M 2' represent L organd R orgin belong to total number of the sub-block of matching area, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, N Δ ψrepresent total number of the phase offset of Gabor filter, N in the present embodiment ω=5, N θ=8, N Δ ψ=9.
2.-5, according to { the S that the training stage obtains i, org| the monocular vision dictionary table D of 1≤i≤N} nc, obtain { y t', test| 1≤t'≤M 1' in the sparse coefficient matrix of each proper vector and { y t', org| 1≤t'≤M 1' in the sparse coefficient matrix of each proper vector, by y t', testsparse coefficient matrix be designated as x t', test, x t', test=(D nc) -1y t', test, by y t', orgsparse coefficient matrix be designated as x t', org, x t', org=(D nc) -1y t', org, wherein, (D nc) -1for D ncinverse matrix.
According to { the S that the training stage obtains i, org| the binocular vision dictionary table D of 1≤i≤N} bf, obtain { z t', test| 1≤t'≤M 2' in the sparse coefficient matrix of each proper vector and { z t', org| 1≤t'≤M 2' in the sparse coefficient matrix of each proper vector, by z t', testsparse coefficient matrix be designated as f t', test, f t', test=(D bf) -1z t', test, by z t', orgsparse coefficient matrix be designated as f t', org, f t', org=(D bf) -1z t', org, wherein, (D bf) -1for D bfinverse matrix.
2.-6, L is calculated testand R testin belong to the local objective evaluation metric of each sub-block of occlusion area, by L testand R testin the local objective evaluation metric of t' sub-block that belongs in all sub-blocks of occlusion area be designated as q t', test, wherein, (x t', test) tfor x t', testtransposed matrix, symbol " || || 2" for asking for the 2-norm sign of matrix, C is controling parameters, gets C=0.02 in the present embodiment.
And calculate L testand R testin belong to the local objective evaluation metric of each sub-block of matching area, by L testand R testin belong to t' sub-block of matching area local objective evaluation metric be designated as p t', test, wherein, (f t', test) tfor f t', testtransposed matrix, symbol " || || 2" for asking for the 2-norm sign of matrix, C is controling parameters, gets C=0.02 in the present embodiment.
2.-7, S is calculated testmonocular image Objective Quality Assessment predicted value, be designated as and calculate S testbinocular image Objective Quality Assessment predicted value, be designated as Q bf,
2.-8, S is calculated testpicture quality objective evaluation predicted value, be designated as Q, Q=w nc× Q nc+ (1-w nc) × Q bf, wherein, w ncfor Q ncweights proportion, get w in the present embodiment nc=0.2.
For further illustrating feasibility and the validity of the inventive method, test assessment is carried out to the inventive method.
Here, utilize 2 of evaluate image quality evaluating method conventional objective parameters as evaluation index, namely Pearson correlation coefficient (the Pearson linear correlation coefficient under non-linear regression condition, PLCC), Spearman related coefficient (Spearman rank order correlation coefficient, SRCC), PLCC reflects the accuracy of the objective evaluation result of distortion stereo-picture, and SRCC reflects its monotonicity.
Utilize the inventive method to calculate the picture quality objective evaluation predicted value of the every width distortion stereo-picture in the picture quality objective evaluation predicted value of the every width distortion stereo-picture in University Of Ningbo's stereo-picture storehouse and LIVE stereo-picture storehouse, recycle the mean subjective scoring difference that existing subjective evaluation method obtains the every width distortion stereo-picture in the mean subjective scoring difference of the every width distortion stereo-picture in University Of Ningbo's stereo-picture storehouse and LIVE stereo-picture storehouse.The picture quality objective evaluation predicted value of the distortion stereo-picture calculated by the inventive method is done five parameter Logistic function nonlinear fittings, PLCC and SRCC value is higher, illustrates that the objective evaluation result of the inventive method and mean subjective difference correlativity of marking is better.Table 1 and table 2 give the picture quality objective evaluation predicted value of distortion stereo-picture that adopts the inventive method to obtain and mean subjective and to mark Pearson correlation coefficient between difference and Spearman related coefficient.As can be seen from Table 1 and Table 2, final picture quality objective evaluation predicted value and the mean subjective correlativity of marking between difference of the distortion stereo-picture adopting the inventive method to obtain are very high, the result indicating objective evaluation result and human eye subjective perception is more consistent, is enough to the validity that the inventive method is described.
Fig. 2 gives the scatter diagram that the picture quality objective evaluation predicted value of the every width distortion stereo-picture in the University Of Ningbo's stereo-picture storehouse utilizing the inventive method to obtain and mean subjective mark difference, Fig. 3 gives the scatter diagram that the picture quality objective evaluation predicted value of the every width distortion stereo-picture in the LIVE stereo-picture storehouse utilizing the inventive method to obtain and mean subjective mark difference, loose point is more concentrated, illustrates that the consistance of objective evaluation result and subjective perception is better.As can be seen from Fig. 2 and Fig. 3, adopt the scatter diagram that obtains of the inventive method more concentrated, and the goodness of fit between subjective assessment data is higher.
The Pearson correlation coefficient that picture quality objective evaluation predicted value and the mean subjective of the distortion stereo-picture that table 1 utilizes the inventive method to obtain are marked between difference compares
The Spearman related coefficient that picture quality objective evaluation predicted value and the mean subjective of the distortion stereo-picture that table 2 utilizes the inventive method to obtain are marked between difference compares

Claims (8)

1. an objective evaluation method for quality of stereo images for view-based access control model fidelity, it is characterized in that comprising training stage and test phase two processes, the described training stage comprises the following steps:
-1 1., choose N original undistorted stereo-picture composing training image set, be designated as { S i, org| 1≤i≤N}, wherein, N>1, S i, orgrepresent { S i, org| i-th in 1≤i≤N} original undistorted stereo-picture;
-2 1., utilize Region detection algorithms, judge { S i, org| each pixel in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image belongs to occlusion area and still belongs to matching area;
-3 1., adopt Gabor filter, obtain { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image;
Then according to { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture, obtains { S i, org| the amplitude of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture;
Equally, according to { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the right visual point image of every in 1≤i≤N} original undistorted stereo-picture, obtains { S i, org| the amplitude of each pixel under different center frequency and the different directions factor in the right visual point image of every in 1≤i≤N} original undistorted stereo-picture;
Further, according to { S i, org| the frequency response of each pixel under different center frequency and the different directions factor in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, obtains { S i, org| the amplitude of each pixel under different center frequency, the skew of different directions Summing Factor out of phase in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image;
1.-4, to { S i, org| left visual point image and the right visual point image of every in 1≤i≤N} original undistorted stereo-picture carry out non-overlapped point sub-block process;
Then K-SVD method is adopted, to by { S i, org| dictionary training and operation is carried out in the proper vector set that all sub-blocks proper vector separately belonging to occlusion area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image is formed, and obtains { S i, org| the monocular vision dictionary table of 1≤i≤N}, is designated as D nc, wherein, the initial value of j is total number that 1, K represents the dictionary of setting, K>=1, represent D ncin a jth visual dictionary, any one sub-block belonging to occlusion area is have the pixel belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of occlusion area is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
Equally, adopt K-SVD method, to by { S i, org| dictionary training and operation is carried out in the proper vector set that all sub-blocks proper vector separately belonging to matching area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image is formed, and obtains { S i, org| the binocular vision dictionary table of 1≤i≤N}, is designated as D bf, wherein, the initial value of j is total number that 1, K represents the dictionary of setting, K>=1, represent D bfin a jth visual dictionary, any one sub-block belonging to matching area is the pixel not belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of matching area is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
Described test phase comprises the following steps:
2. for any one secondary test stereo-picture S test, by S testcorresponding original undistorted stereo-picture is designated as S org;
According to step 1.-2 to step 1.-3 process, with identical operation obtain S testand S orgthe amplitude of each pixel under different center frequency and the different directions factor in respective left visual point image and right visual point image, and obtain S testand S orgthe amplitude of each pixel under different center frequency, the skew of different directions Summing Factor out of phase in respective left visual point image and right visual point image;
By S testleft visual point image and right visual point image in belong to occlusion area all sub-blocks proper vector separately form a proper vector set, by S orgleft visual point image and right visual point image in belong to occlusion area all sub-blocks proper vector separately form a proper vector set, any one sub-block belonging to occlusion area is have the pixel belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of occlusion area is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block; By S testleft visual point image and right visual point image in belong to all sub-blocks of matching area proper vector form a proper vector set, by S orgleft visual point image and right visual point image in belong to all sub-blocks of matching area proper vector form a proper vector set, any one sub-block belonging to matching area is the pixel not belonging to occlusion area in this sub-block, and the proper vector belonging to any one sub-block of matching area is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
According to { the S that the training stage obtains i, org| the monocular vision dictionary table D of 1≤i≤N} nc, the sparse coefficient matrix of each proper vector in two proper vector set that acquisition occlusion area is correlated with; And { the S obtained according to the training stage i, org| the binocular vision dictionary table D of 1≤i≤N} bf, the sparse coefficient matrix of each proper vector in two proper vector set that acquisition matching area is correlated with;
Two the proper vectors sparse coefficient matrix separately corresponding according to position in two proper vector set that occlusion area is correlated with, obtains S testleft visual point image and right visual point image in the local objective evaluation metric of corresponding sub-block; And two proper vectors sparse coefficient matrix separately that in two proper vector set of being correlated with according to matching area, position is corresponding, obtain S testleft visual point image and right visual point image in the local objective evaluation metric of corresponding sub-block;
According to S testleft visual point image and right visual point image in belong to local objective evaluation metric and the S of each sub-block of occlusion area testleft visual point image and right visual point image in belong to the local objective evaluation metric of each sub-block of matching area, obtain S testpicture quality objective evaluation predicted value.
2. the objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity according to claim 1, is characterized in that the detailed process of the Region detection algorithms of described step 1. in-2 is:
A1, by { S i, org| current pending i-th original undistorted stereo-picture S in 1≤i≤N} i, orgbe defined as current stereo-picture, by current stereo-picture S i, orgleft visual point image be defined as when front left visual point image, by current stereo-picture S i, orgright visual point image be defined as when front right visual point image, wherein, the initial value of i is 1;
A2, the anaglyph adopting Block Matching Algorithm calculating to work as front left visual point image and work as between front right visual point image, be designated as { d i, org(x, y) }, wherein, 1≤x≤W, 1≤y≤H, W represents { S i, org| the width of the original undistorted stereo-picture in 1≤i≤N}, H represents { S i, org| the height of the original undistorted stereo-picture in 1≤i≤N}, d i, org(x, y) represents { d i, org(x, y) } in coordinate position be the pixel value of the pixel of (x, y);
A3, basis { d i, org(x, y) } in the pixel value of each pixel, judge still to belong to matching area when each pixel in front left visual point image belongs to occlusion area; For being the pixel of (x, y) when coordinate position in front left visual point image, if d i, org(x, y)=255, then judge when coordinate position in front left visual point image belongs to occlusion area, if d as the pixel of (x, y) i, org(x, y) ≠ 255, then judge when coordinate position in front left visual point image belongs to matching area as the pixel of (x, y);
A4, when in front right visual point image, the pixel corresponding with when each pixel belonging to matching area in front left visual point image is judged to belong to matching area; Then be judged to belong to occlusion area by when all pixels in front right visual point image except belonging to matching area;
A5, make i=i+1, by { S i, org| in 1≤i≤N}, next pending original undistorted stereo-picture is as current stereo-picture, using the left visual point image of current stereo-picture as working as front left visual point image, using the right visual point image of current stereo-picture as working as front right visual point image, then return step a2 to continue to perform, until { S i, org| till all original undistorted stereo-picture in 1≤i≤N} is disposed, wherein, "=" in i=i+1 is assignment.
3. the objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity according to claim 1 and 2, it is characterized in that described step 1.-3 detailed process be:
B1, by { S i, org| current pending i-th original undistorted stereo-picture S in 1≤i≤N} i, orgbe defined as current stereo-picture, by current stereo-picture S i, orgleft visual point image be defined as when front left visual point image, by current stereo-picture S i, orgright visual point image be defined as when front right visual point image, wherein, the initial value of i is 1;
B2, employing Gabor filter carry out filtering process to when front left visual point image, obtain when the frequency response of each pixel under different center frequency and the different directions factor in front left visual point image, be that the pixel of (x, y) is designated as in the centre frequency frequency response that to be ω and direction factor be under θ by working as coordinate position in front left visual point image
Equally, Gabor filter is adopted to carry out filtering process to when front right visual point image, obtain when the frequency response of each pixel under different center frequency and the different directions factor in front right visual point image, be that the pixel of (x, y) is designated as in the centre frequency frequency response that to be ω and direction factor be under θ by working as coordinate position in front right visual point image G i , org R ( x , y ; &omega; , &theta; ) ;
Above-mentioned, 1≤x≤W, 1≤y≤H, W represents { S i, org| the width of the original undistorted stereo-picture in 1≤i≤N}, H represents { S i, org| the height of the original undistorted stereo-picture in 1≤i≤N}, ω represents the centre frequency of adopted Gabor filter, ω ∈ Ω ω, Ω ωrepresent the set of the centre frequency of the Gabor filter adopted, θ represents the direction factor of adopted Gabor filter, θ ∈ Ω θ, Ω θrepresent the set of the direction factor of the Gabor filter adopted;
B3, basis are when the frequency response of each pixel under different center frequency and the different directions factor in front left visual point image, calculate when the amplitude of each pixel under different center frequency and the different directions factor in front left visual point image, be that the pixel of (x, y) is designated as at the centre frequency amplitude that to be ω and direction factor be under θ by working as coordinate position in front left visual point image E i , org L ( x , y ; &omega; , &theta; ) = | | G i , org L ( x , y ; &omega; , &theta; ) | | 2 2 , Wherein, symbol " || || 2" for asking for the 2-norm sign of matrix;
Equally, according to the frequency response of each pixel under different center frequency and the different directions factor of working as in front right visual point image, calculate when the amplitude of each pixel under different center frequency and the different directions factor in front right visual point image, be that the pixel of (x, y) is designated as at the centre frequency amplitude that to be ω and direction factor be under θ by working as coordinate position in front right visual point image E i , org R ( x , y ; &omega; , &theta; ) = | | G i , org R ( x , y ; &omega; , &theta; ) | | 2 2 , Wherein, symbol " || || 2" for asking for the 2-norm sign of matrix;
B4, basis are when front left visual point image with when the frequency response of each pixel under different center frequency and the different directions factor in front right visual point image, calculate when front left visual point image with when the amplitude of each pixel in front right visual point image under different center frequency, the skew of different directions Summing Factor out of phase, by work as front left visual point image and when front right visual point image separately middle coordinate position be (x, y) pixel centre frequency be ω, the direction factor amplitude that to be θ and phase offset be under Δ ψ is designated as E i , org LR ( x , y ; &omega; , &theta; , &Delta;&psi; ) = | | G i , org L ( x , y ; &omega; , &theta; ) + e j&Delta;&psi; &times; G i , org R ( x , y ; &omega; , &theta; ) | | 2 2 , Wherein, Δ ψ ∈ Ω Δ ψ, Ω Δ ψrepresent the set of the phase offset of the Gabor filter adopted, symbol " || || 2" for asking for the 2-norm sign of matrix, e represents nature radix, j is imaginary unit;
B5, make i=i+1, by { S i, org| in 1≤i≤N}, next pending original undistorted stereo-picture is as current stereo-picture, using the left visual point image of current stereo-picture as working as front left visual point image, using the right visual point image of current stereo-picture as working as front right visual point image, then return step b2 to continue to perform, until { S i, org| till all original undistorted stereo-picture in 1≤i≤N} is disposed, wherein, "=" in i=i+1 is assignment.
4. the objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity according to claim 3, it is characterized in that described step 1.-4 detailed process be:
C1, by { S i, org| left visual point image and the right visual point image of every in 1≤i≤N} original undistorted stereo-picture are divided into respectively individual size is the sub-block of the non-overlapping copies of 8 × 8, wherein, and W represents { S i, org| the width of the original undistorted stereo-picture in 1≤i≤N}, H represents { S i, org| the height of the original undistorted stereo-picture in 1≤i≤N};
C2, determine { S i, org| belong to all sub-blocks of occlusion area in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, for S i, orgleft visual point image and right visual point image in any one sub-block, if there is the pixel belonging to occlusion area in this sub-block, then determine that this sub-block belongs to occlusion area;
And by { S i, org| all sub-blocks in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image except the sub-block belonging to occlusion area are defined as belonging to matching area;
C3, acquisition { S i, org| belong to the proper vector of each sub-block of occlusion area in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, for S i, orgleft visual point image and right visual point image in belong to any one sub-block of occlusion area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
And obtain { S i, org| belong to the proper vector of each sub-block of matching area in the left visual point image of every in 1≤i≤N} original undistorted stereo-picture and right visual point image, for S i, orgleft visual point image and right visual point image in belong to any one sub-block of matching area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
C4, by { S i, org| all sub-blocks proper vector separately belonging to occlusion area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image forms a proper vector set, is designated as { y t| 1≤t≤M 1, wherein, y tfor { y t| 1≤t≤M 1in t proper vector, y tdimension be 64 × N ω× N θ, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, M 1represent { S i, org| belong to total number of the sub-block of occlusion area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image,
And by { S i, org| the proper vector belonging to all sub-blocks of matching area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image forms a proper vector set, is designated as { z t| 1≤t≤M 2, wherein, z tfor { z t| 1≤t≤M 2in t proper vector, z tdimension be 64 × N ω× N θ× N Δ ψ, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, N Δ ψrepresent total number of the phase offset of Gabor filter, M 2represent { S i, org| belong to total number of the sub-block of matching area in the left visual point image of all original undistorted stereo-picture in 1≤i≤N} and right visual point image, M 2 < W &times; H &times; N 64 ;
C5, employing K-SVD method are to { y t| 1≤t≤M 1carry out dictionary training and operation, obtain { y t| 1≤t≤M 1visual dictionary table, and by { y t| 1≤t≤M 1visual dictionary table as { S i, org| the monocular vision dictionary table of 1≤i≤N}, is designated as D nc, d ncsolved by K-SVD method obtain, constraint condition be: wherein, D ncdimension be (64 × N ω× N θ) × K, K represents total number of the dictionary of setting, K>=1, represent D ncin a jth dictionary, min () for getting minimum value function, symbol " || || 2" for asking for the 2-norm sign of matrix, y ncdimension be (64 × N ω× N θ) × M 1, y 1represent { y t| 1≤t≤M 1in the 1st proper vector, y trepresent { y t| 1≤t≤M 1in t proper vector, represent { y t| 1≤t≤M 1in M 1individual proper vector, X ncrepresent sparse matrix, x ncdimension be K × M 1, x 1represent X ncin the 1st row, x trepresent X ncin t row, represent X ncin M 1row, symbol " [] " is vector representation symbol, represent existence t, symbol " || || 0" for asking for the 0-norm sign of matrix, τ is error coefficient;
And adopt K-SVD method to { z t| 1≤t≤M 2carry out dictionary training and operation, obtain { z t| 1≤t≤M 2visual dictionary table, and by { z t| 1≤t≤M 2visual dictionary table as { S i, org| the binocular vision dictionary table of 1≤i≤N}, is designated as D bf, d bfsolved by K-SVD method obtain, constraint condition be: wherein, D bfdimension be (64 × N ω× N θ× N Δ ψ) × K, K represents total number of the dictionary of setting, K>=1, represent D bfin a jth dictionary, min () for getting minimum value function, symbol " || || 2" for asking for the 2-norm sign of matrix, z bfdimension be (64 × N ω× N θ× N Δ ψ) × M 2, z 1for { z t| 1≤t≤M 2in the 1st proper vector, z tfor { z t| 1≤t≤M 2in t proper vector, for { z t| 1≤t≤M 2in M 2individual proper vector, F bfrepresent sparse matrix, f bfdimension be K × M 2, f 1represent F bfin the 1st row, f trepresent F bfin t row, represent F bfin M 2row, symbol " [] " is vector representation symbol, represent existence t, symbol " || || 0" for asking for the 0-norm sign of matrix, τ is error coefficient.
5. the objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity according to claim 4, is characterized in that getting τ=0.1 in described step c5.
6. the objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity according to claim 4, is characterized in that described step detailed process is 2.:
2.-1, by S testleft visual point image be designated as L test, by S testright visual point image be designated as R test, by S testcorresponding original undistorted stereo-picture is designated as S org, by S orgleft visual point image be designated as L org, by S orgright visual point image be designated as R org;
-2 2., according to step 1.-2 process, judge L with identical operation testand R testin each pixel belong to occlusion area and still belong to matching area, and judge L organd R orgin each pixel belong to occlusion area and still belong to matching area;
-3 2., according to step 1.-3 process, obtain L with identical operation testin amplitude, the R of each pixel under different center frequency and the different directions factor testin amplitude, the L of each pixel under different center frequency and the different directions factor testand R testin the amplitude of each pixel under different center frequency, the skew of different directions Summing Factor out of phase, and obtain L orgin amplitude, the R of each pixel under different center frequency and the different directions factor orgin amplitude, the L of each pixel under different center frequency and the different directions factor organd R orgin each pixel different center frequency, different directions Summing Factor out of phase skew under amplitude;
2.-4, to L testand R testand L organd R orgcarry out non-overlapped point sub-block process respectively;
Then L is determined testand R testand L organd R orgin belong to all sub-blocks of occlusion area, for L testand R testand L organd R orgin any one sub-block, if there is the pixel belonging to occlusion area in this sub-block, then determine that this sub-block belongs to occlusion area; And by L testand R testand L organd R orgin all sub-blocks except the sub-block belonging to occlusion area be defined as belonging to matching area;
Then L is obtained testand R testand L organd R orgin belong to the proper vector of each sub-block of occlusion area, for L testand R testand L organd R orgin belong to any one sub-block of occlusion area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies and direction factor in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block; And obtain L testand R testand L organd R orgin belong to the proper vector of each sub-block of matching area, for L testand R testand L organd R orgin belong to any one sub-block of matching area, the proper vector of this sub-block is that the amplitude of all pixels under all centre frequencies, direction factor and phase offset in this sub-block is formed by the sequencing arrangement of the coordinate position of each pixel in this sub-block;
Afterwards by L testand R testin belong to occlusion area all sub-blocks proper vector separately form a proper vector set, be designated as { y t', test| 1≤t'≤M 1' ,and by L testand R testin belong to all sub-blocks of matching area proper vector form a proper vector set, be designated as { z t', test| 1≤t'≤M 2', wherein, y t', testfor { y t', test| 1≤t'≤M 1' in t' proper vector, y t', testdimension be 64 × N ω× N θ, at this M 1' represent L testand R testin belong to total number of the sub-block of occlusion area, z t', testfor { z t', test| 1≤t'≤M 2' in t' proper vector, z t', testdimension be 64 × N ω× N θ× N Δ ψ, at this M 2' represent L testand R testin belong to total number of the sub-block of matching area, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, N Δ ψrepresent total number of the phase offset of Gabor filter;
Equally, by L organd R orgin belong to occlusion area all sub-blocks proper vector separately form a proper vector set, be designated as { y t', org| 1≤t'≤M 1', and by L organd R orgin belong to all sub-blocks of matching area proper vector form a proper vector set, be designated as { z t', org| 1≤t'≤M 2', wherein, y t', orgfor { y t', org| 1≤t'≤M 1' in t' proper vector, y t', orgdimension be 64 × N ω× N θ, at this M 1' represent L organd R orgin belong to total number of the sub-block of occlusion area, z t', orgfor { z t', org| 1≤t'≤M 2' in t' proper vector, z t', orgdimension be 64 × N ω× N θ× N Δ ψ, at this M 2' represent L organd R orgin belong to total number of the sub-block of matching area, N ωrepresent total number of the centre frequency of Gabor filter, N θrepresent total number of the direction factor of Gabor filter, N Δ ψrepresent total number of the phase offset of Gabor filter;
2.-5, according to { the S that the training stage obtains i, org| the monocular vision dictionary table D of 1≤i≤N} nc, obtain { y t', test| 1≤t'≤M 1' in the sparse coefficient matrix of each proper vector and { y t', org| 1≤t'≤M 1' in the sparse coefficient matrix of each proper vector, by y t', testsparse coefficient matrix be designated as x t', test, x t', test=(D nc) -1y t', test, by y t', orgsparse coefficient matrix be designated as x t', org, x t', org=(D nc) -1y t', org, wherein, (D nc) -1for D ncinverse matrix;
According to { the S that the training stage obtains i, org| the binocular vision dictionary table D of 1≤i≤N} bf, obtain { z t', test| 1≤t'≤M 2' in the sparse coefficient matrix of each proper vector and { z t', org| 1≤t'≤M 2' in the sparse coefficient matrix of each proper vector, by z t', testsparse coefficient matrix be designated as f t', test, f t', test=(D bf) -1z t', test, by z t', orgsparse coefficient matrix be designated as f t', org, f t', org=(D bf) -1z t', org, wherein, (D bf) -1for D bfinverse matrix;
2.-6, L is calculated testand R testin belong to the local objective evaluation metric of each sub-block of occlusion area, by L testand R testin the local objective evaluation metric of t' sub-block that belongs in all sub-blocks of occlusion area be designated as q t', test, wherein, (x t', test) tfor x t', testtransposed matrix, symbol " || || 2" for asking for the 2-norm sign of matrix, C is controling parameters;
And calculate L testand R testin belong to the local objective evaluation metric of each sub-block of matching area, by L testand R testin belong to t' sub-block of matching area local objective evaluation metric be designated as p t', test, wherein, (f t', test) tfor f t', testtransposed matrix, symbol " || || 2" for asking for the 2-norm sign of matrix, C is controling parameters;
2.-7, S is calculated testmonocular image Objective Quality Assessment predicted value, be designated as Q nc, and calculate S testbinocular image Objective Quality Assessment predicted value, be designated as Q bf,
2.-8, S is calculated testpicture quality objective evaluation predicted value, be designated as Q, Q=w nc× Q nc+ (1-w nc) × Q bf, wherein, w ncfor Q ncweights proportion.
7. the objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity according to claim 6, is characterized in that 2. described step gets C=0.02 in-6.
8. the objective evaluation method for quality of stereo images of a kind of view-based access control model fidelity according to claim 7, is characterized in that 2. described step gets w in-8 nc=0.2.
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