METHOD AND SYSTEM FOR DETERMINING A QUALITY MEASURE FOR AN IMAGE USING MULTI-LEVEL DECOMPOSITION OF IMAGES
First Claim
1. A method for determining a measure of quality for a distorted image Y, characterizing a similarity between the image Y and an undistorted reference image X, having the same number of rows and columns of pixels as the image Y, the method comprising:
- (a1) applying a N level multiresolution decomposition, comprising levels 1, 2, . . . i, i+1, . . . N, to the image X, to produce;
for each level i, with i ranging from 1 to N−
1, intermediate subbands of image X for processing at level 41; and
for the level N, an approximation subband containing main content of the image X and detail subbands containing edges of the image X;
(b1) applying said N level multiresolution decomposition, comprising levels 1, 2, . . . i, i+1, . . . N, to the image Y, to produce;
for each level i, with i ranging from 1 to N−
1, intermediate subbands of image Y for processing at level 41; and
for the level, N, an approximation subband containing main content of the image Y and detail subbands containing edges of the image Y;
(c1) applying an image quality metric (IQM) to the approximation subband of the image X and the approximation subband of the image Y to produce an approximation quality measure characterizing similarity between the main content of the image X and the main content of the image Y;
(d1) aggregating the intermediate subbands at the level i for the image X, with i ranging from levels 1 to N−
1, and the detail subbands of the image X to produce an edge map of the image X characterizing the edges of the image X;
(e1) aggregating the intermediate subbands at the level i for the image Y, with i ranging from 1 to N−
1, and the detail subbands of the image Y to produce an edge map of the image Y characterizing the edges of image Y;
(f1) applying the IQM between the edge map of the image X and the edge map of the image Y to produce an edge quality measure characterizing similarity between the edges of the image X and the edges of the image Y; and
(g1) processing the approximation quality measure and the edge quality measure to determine the measure of quality.
7 Assignments
0 Petitions
Accused Products
Abstract
Method and system for determining a measure of quality for images by using multi-level decomposition are presented. Multi-level decomposition of images is performed in the wavelet domain producing subbands at each level of decomposition. Aggregation of subbands is performed across multiple levels to produce an accurate measure of image quality. By aggregating only selected subbands the computational complexity of the method is greatly reduced.
-
Citations
49 Claims
-
1. A method for determining a measure of quality for a distorted image Y, characterizing a similarity between the image Y and an undistorted reference image X, having the same number of rows and columns of pixels as the image Y, the method comprising:
-
(a1) applying a N level multiresolution decomposition, comprising levels 1, 2, . . . i, i+1, . . . N, to the image X, to produce; for each level i, with i ranging from 1 to N−
1, intermediate subbands of image X for processing at level 41; andfor the level N, an approximation subband containing main content of the image X and detail subbands containing edges of the image X; (b1) applying said N level multiresolution decomposition, comprising levels 1, 2, . . . i, i+1, . . . N, to the image Y, to produce; for each level i, with i ranging from 1 to N−
1, intermediate subbands of image Y for processing at level 41; andfor the level, N, an approximation subband containing main content of the image Y and detail subbands containing edges of the image Y; (c1) applying an image quality metric (IQM) to the approximation subband of the image X and the approximation subband of the image Y to produce an approximation quality measure characterizing similarity between the main content of the image X and the main content of the image Y; (d1) aggregating the intermediate subbands at the level i for the image X, with i ranging from levels 1 to N−
1, and the detail subbands of the image X to produce an edge map of the image X characterizing the edges of the image X;(e1) aggregating the intermediate subbands at the level i for the image Y, with i ranging from 1 to N−
1, and the detail subbands of the image Y to produce an edge map of the image Y characterizing the edges of image Y;(f1) applying the IQM between the edge map of the image X and the edge map of the image Y to produce an edge quality measure characterizing similarity between the edges of the image X and the edges of the image Y; and (g1) processing the approximation quality measure and the edge quality measure to determine the measure of quality. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
-
-
25. A system for determining a measure of quality for a distorted image Y, characterizing a similarity between the image Y and an undistorted reference image X, having the same number of rows and columns of pixels as the image Y, the system comprising:
-
a processor, and a computer readable storage medium having computer readable instructions stored thereon, which, when executed by the processor, form the following; (a25) a first decomposition unit applying a N level multiresolution decomposition, comprising levels 1, 2, . . . i, i+1, . . . N, to the image X, to produce; for each level i, with i ranging from 1 to N−
1, intermediate subbands of image X for processing at level i+1; andfor the level N, an approximation subband containing main content of the image X and detail subbands containing edges of the image X; (b25) a second decomposition unit applying said N level multiresolution decomposition, comprising levels 1, 2, . . . i, i+1, . . . N, to the image Y, to produce; for each level i, with i ranging from 1 to N−
1, intermediate subbands for image Y; andfor the level, N, an approximation subband containing main content of the image Y and detail subbands containing edges of the image Y; (c25) an approximation quality measure unit applying an image quality metric (IQM) to the approximation subband of the image X and the approximation subband of the image Y to produce an approximation quality measure characterizing similarity between the main content of the image X and the main content of the image Y; (d25) a first aggregation unit aggregating the intermediate subbands at the level i for the image X, with i ranging from levels 1 to N−
1 and the detail subbands of the image X to produce an edge map of the image X characterizing the edges of the image X;(e25) a second aggregation unit aggregating the intermediate subbands at the level i for the image Y, with i ranging from 1 to N−
1 and the detail subbands of the image Y to produce an edge map of the image Y characterizing the edges of image Y;(f25) an edge quality measure unit applying the IQM between the edge map of the image X and the edge map of the image Y to produce an edge quality measure characterizing similarity between the edges of the image X and the edges of the image Y; and (g25) a quality measure unit processing the approximation quality measure and the edge quality measure to determine the measure of quality. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
-
-
49. A computer readable storage medium, having computer readable program code instructions stored thereon, which, when executed by a processor, perform the following:
-
(a49) applying a N level multiresolution decomposition, comprising levels 1, 2, . . . i, i+1, . . . N, to the image X, to produce; for each level i, with i ranging from 1 to N−
1, intermediate subbands of image X for processing at level i+1; andfor the level N, an approximation subband containing main content of the image X and detail subbands containing edges of the image X; (b49) applying said N level multiresolution decomposition, comprising levels 1, 2, . . . i, i+1, . . . N, to the image Y, to produce; for each level i, with i ranging from 1 to N−
1, intermediate subbands of image Y for processing at level i+1; andfor the level, N, an approximation subband containing main content of the image Y and detail subbands containing edges of the image Y; (c49) applying an image quality metric (IQM) to the approximation subband of the image X and the approximation subband of the image Y to produce an approximation quality measure characterizing similarity between the main content of the image X and the main content of the image Y; (d49) aggregating the intermediate subbands at the level i for the image X, with i ranging from levels 1 to N−
1, and the detail subbands of the image X to produce an edge map of the image X characterizing the edges of the image X;(e49) aggregating the intermediate subbands at the level i for the image Y, with i ranging from 1 to N−
1, and the detail subbands of the image Y to produce an edge map of the image Y characterizing the edges of image Y;(f49) applying the IQM between the edge map of the image X and the edge map of the image Y to produce an edge quality measure characterizing similarity between the edges of the image X and the edges of the image Y; and (g49) processing the approximation quality measure and the edge quality measure to determine the measure of quality.
-
Specification