Stereo image quality objective evaluation method based on gradient structure tensor

Abstract

The invention discloses a stereo image quality objective evaluation method based on a gradient structure tensor. The method comprises the following steps of: calculating the gradient structure tensor of each pixel point by calculating a horizontal gradient, a perpendicular gradient and a viewpoint gradient of each pixel point in a left viewpoint image of a stereo image, and performing matrix resolving to obtain a characteristic value and a characteristic vector of the gradient structure tensor of each pixel point; then dividing the left viewpoint image into a sensitive region and a non-sensitive region by using a region detection method; and finally obtaining a final image quality objective evaluation forecast value according to the region type of each pixel. The stereo image quality objective evaluation method has the advantages that the characteristic value and the characteristic vector of the gradient structure tensor are relatively high in stability and can well reflect the quality change of the stereo image; and furthermore, the pixel points in the sensitive region can be evaluated, so that the relativity between an objective evaluation result and subjective perception can be effectively improved.

Description

technical field [0001] The invention relates to an image quality evaluation method, in particular to an objective evaluation method of stereoscopic image quality based on gradient structure tensor. Background technique [0002] With the rapid development of image coding technology and stereoscopic display technology, stereoscopic image technology has received more and more attention and applications, and has become a current research hotspot. Stereoscopic image technology utilizes the binocular parallax principle of the human eye. Both eyes independently receive left and right viewpoint images from the same scene, and form binocular parallax through brain fusion, so as to enjoy a stereoscopic image with a sense of depth and realism. Due to the influence of acquisition system, storage compression and transmission equipment, stereoscopic images will inevitably introduce a series of distortions. Compared with single-channel images, stereoscopic images need to ensure the image q...

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Problems solved by technology

[0003] The gradient structure tensor is an analysis method to describe the structural information of a local point in the image, and the structural analysis method has been widely used in the quality evaluation of planar images, such as the classic Structural Similarity Index (SSIM), however The existing gradient structure tensor is mainly used in video quality evaluation. For the stereo image quality evaluation based on the gradient structure tensor, the following key problems need to be solved: 1) The stereo perception evaluation is reflected by disparity or depth information. Or depth information is embedded into the gradient structure tensor to truly represent the stereoscopic perception characteristics, which is still one of the difficult problems in the objective evaluation of stereoscopic image quality; 2) Not all pixels have strong structural information, how to choose a stable structure The application of information to quality evaluation without affecting the stereo perception performance is also a difficult problem to be solved in the objective evaluation of stereo image quality

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