Exposure control method for human face image acquisition system under near-infrared condition

Abstract

The invention discloses an exposure control method for a human face image acquisition system under a near-infrared condition. The method is combined with a human face image information entropy and a human face image motion-blur extent to carry out exposure control, and comprises the following steps: a), using the human face image information entropy as an optimal human face image brightness judgment value, and determining the exposure time for optimal human face brightness through finding the maximum value of the human face image information entropy; b), estimating the human face image motion-blur extent through being combined with cepstrum and the interframe movement distance of a human face; c) adjusting the exposure time according to the human face image motion-blur extent. The exposure control method can be applicable to the human face image acquisition system under the near-infrared condition, can overcome the image degradation phenomenon of the human face image acquisition system due to illumination variation and motion blur effectively, improves the quality of the acquired human face images, and ensures the stability and the accuracy of human face image processing analysis.

Description

technical field [0001] The invention relates to an exposure control technology in image processing and image acquisition, in particular to an exposure control method for a face image acquisition system under near-infrared conditions. Background technique [0002] Various biometric recognition systems based on face images use machine vision technology to simulate human visual functions and image analysis and comprehension capabilities by computer, and extract the required feature information from face images to complete identification of people and fatigue status. detection work, etc. Although relevant researches have been developed by leaps and bounds, most of them are still in the stage of laboratory verification. One of the important constraints is that the degradation of image quality in the actual use environment leads to a decrease in the accuracy of the system. In the actual application environment, changes in illumination, uneven illumination, and relative motion wil...

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the defect of the exposure control method of the existing face image acquisition system, by designing an exposure control method that combines the information entropy of the face image and the motion blur scale of the face image, effectively overcome the problem caused by the illumination of the face image acquisition system. Image degradation caused by changes and motion blur, improve the quality of collected face images, and ensure the stability and accuracy of face image processing and analysis

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