MACROBLOCK LEVEL NO-REFERENCE OBJECTIVE QUALITY ESTIMATION OF VIDEO
A no-reference estimation of video quality in streaming video is provided on a macroblock basis. Compressed video is being deployed in video in streaming and transmission applications. MB-level no-reference objective quality estimation is provided based on machine learning techniques. First the feature vectors are extracted from both the MPEG coded bitstream and the reconstructed video. Various feature extraction scenarios are proposed based on bitstream information, MB prediction error, prediction source and reconstruction intensity. The features are then modeled using both a reduced model polynomial network and a Bayes classifier. The classified features may be used as feature vector used by a client device assess the quality of received video without use of the original video as a reference.
1 . A method for assessing a quality level of received video signal, comprising the steps of:
labeling individual macroblocks of a decoded video according to a determination of quality measurement;
extracting at least one feature associated with each macroblock of the decoded video;
classifying feature vectors associating the at least one extracted feature with the quality measurement.
2 . The method of claim 1 , wherein the quality measurement includes a peak signal to noise ratio measurement, and an identification of a plurality of quality classes.
3 . The method of claim 1 , wherein the feature of a macroblock includes at least one of: average macroblock border SAD; macroblock number of coding bits; macroblock quant stepsize; macroblock variance of coded prediction error or intensity; macroblock type; Magnitude of motion vector; Phase of motion vector; average macroblock motion vector border magnitude; average macroblock motion vector border phase; macroblock distance from last sync marker; macroblock sum of absolute high frequencies; macroblock sum of absolute Sobel edges; macroblock dist. from last intra macroblock; Texture mean; Texture Standard deviation; Texture Smoothness; Texture 3 rd moment; Texture Uniformity; Texture Entropy; or macroblock coded block pattern
4 . The method of claim 1 , further comprising the step of expanding a feature vector based on the at least one extracted feature as a polynomial.
5 . The method of claim 4 , wherein a global matrix for each quality class of a plurality of quality classes is obtained.
6 . The method of claim 1 , wherein the step of classifying includes using a statistical classifier.
7 . An apparatus for assessing a quality level of received video signal, comprising:
a quality classifier which classifies quality levels of macroblocks of a video signal based on a quality measurement of each macroblocks of the video signal;
a feature extraction unit which identifies at least one feature of each macroblock of the macroblocks of the video signal;
a classifier which classifies the at least one features of the macroblock with the detected quality level of the corresponding macroblocks.
8 . The apparatus of claim 7 , wherein the quality measurement includes a peak signal to noise ratio measurement, and an identification of a plurality of quality classes.
9 . The apparatus of claim 7 , wherein the feature of a macroblock includes at least one of average macroblock border SAD; macroblock number of coding bits; macroblock quant stepsize; macroblock variance of coded prediction error or intensity; macroblock type; Magnitude of motion vector; Phase of motion vector; average macroblock motion vector border magnitude; average macroblock motion vector border phase; macroblock distance from last sync marker; macroblock sum of absolute high frequencies; macroblock sum of absolute Sobel edges; macroblock dist. from last intra macroblock; Texture mean; Texture Standard deviation; Texture Smoothness; Texture 3 rd moment; Texture Uniformity; Texture Entropy; or macroblock coded block pattern
10 . The apparatus of claim 7 , further comprising an expander which expands a feature vector based on the at least one extracted feature as a polynomial.
11 . The apparatus of claim 10 , wherein a global matrix for each quality class of a plurality of quality classes is obtained.
12 . The apparatus of claim 7 , wherein the classifier is a statistical classifier.
13 . A computer readable medium containing instructions for a computer to perform a method for identifying a quality level of received video signal, comprising the steps of:
labeling macroblocks of a decoded video according to a determination of quality measurement;
extracting at least one feature associated with each macroblock of the decoded video;
classifying feature vectors associating the at least one extracted feature with the quality measurement.
14 . The computer readable medium of claim 13 , wherein the quality measurement includes a peak signal to noise ratio measurement, and an identification of a plurality of quality classes.
15 . The computer readable medium of claim 13 , wherein the feature of a macroblock includes at least one of: average macroblock border SAD; macroblock number of coding bits; macroblock quant stepsize; macroblock variance of coded prediction error or intensity; macroblock type; Magnitude of motion vector; Phase of motion vector; average macroblock motion vector border magnitude; average macroblock motion vector border phase; macroblock distance from last sync marker; macroblock sum of absolute high frequencies; macroblock sum of absolute Sobel edges; macroblock dist. from last intra macroblock; Texture mean; Texture Standard deviation; Texture Smoothness; Texture 3 rd moment; Texture Uniformity; Texture Entropy; or macroblock coded block pattern
16 . The computer readable medium of claim 13 , further comprising the step of expanding a feature vector based on the at least one extracted feature as a polynomial.
17 . The computer readable medium of claim 16 , wherein a global matrix for each quality class of a plurality of quality classes is obtained.
18 . The computer readable medium of claim 13 , wherein the step of classifying includes using a statistical classifier.
19 . An apparatus for identifying a quality level of received video signal, comprising:
a decoder which decodes received video macroblocks;
a feature extraction unit which identifies at least one feature of each macroblock of the macroblocks of the video signal;
a classifier which identifies the macroblock as a quality level based on the at least one feature and classified feature vectors associating features with an a representation of video quality.
20 . The apparatus of claim 19 , wherein the feature of a macroblock includes at least one of: average macroblock border SAD; macroblock number of coding bits; macroblock quant stepsize; macroblock variance of coded prediction error or intensity; macroblock type; Magnitude of motion vector; Phase of motion vector; average macroblock motion vector border magnitude; average macroblock motion vector border phase; macroblock distance from last sync market; macroblock sum of absolute high frequencies; macroblock sum of absolute Sobel edges; macroblock dist. from last intra macroblock; Texture mean; Texture Standard deviation; Texture Smoothness; Texture 3 rd moment; Texture Uniformity; Texture Entropy; or macroblock coded block pattern
21 . The apparatus of claim 19 , further comprising an expander which expands a feature vector based on the at least one extracted feature as a polynomial.
22 . The apparatus of claim 19 , wherein the classifier is a statistical classifier.