Image reflection removing device and method based on photometric stereo

Abstract

The invention discloses an image reflection removing device and a method based on photometric stereo, which belong to the technical field of machine vision and video image processing. Four light sources with consistent light intensity are firstly mounted at proper positions, and the illumination angle of each light source is determined through light source calibration; a picture is photographed in a condition in which the four light sources are lighted separately, Gaussian filtering is used to pre-process the obtained four images to remove white noise, the gray adjustment parameter of each pixel is then solved, and according to the parameter, the gray value of a point with reflection existing possibly is adjusted; and the four images after processing form an overdetermined equation according to a photometric stereo algorithm, an albedo graph is solved, and images with reflection removed are thus acquired. On one hand, the four images are used as the photometric stereo to remove reflection, and good robustness is realized in shadows formed by occlusion and a complicated pattern; and on the other hand, decoupling between the image and the light source is realized, and a more accurate reflection-removed image can be acquired.

Description

technical field [0001] The invention relates to the technical field of machine vision and video image processing, and more specifically, to a device and method for removing reflections from an image based on photometric stereo. Background technique [0002] The application of machine vision in the field of quality inspection of industrial products is becoming more and more common. However, the surface of many products is prone to reflection, which causes some areas of the image to be covered by highlights after the camera captures the image, and surface information such as texture, characters or labels are also lost. Image detection algorithms are much less effective. [0003] At present, methods for removing reflections in industry are mainly divided into two categories: multi-image input and single-image input. Image reflections are removed based on the complementarity of multi-image highlight areas, such as image stitching and average image methods. The above methods eit...

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Problems solved by technology

[0009] The problem to be solved by the present invention is: the application demand of machine vision in the quality inspection of industrial products is increasing day by day, and the effect of the image detection algorithm will be greatly reduced by the reflection; The amount is large, which does not meet the real-time requirements of industrial production; and the existing methods that can quickly remove reflections can only deal with specific products, and the removal effect on products with other complex patterns is poor. In summary, the existing methods are difficult To achieve the compatibility of high real-time and high accuracy rate, a device and method for removing image reflection based on photometric stereo are provided; the present invention uses four light sources to shoot four images respectively, and uses photometric stereo Solve the albedo map and replace the gray value of the corresponding pixel with the albedo to remove the reflection of the image. It is not only efficient and robust, but also the obtained image is completely decoupled from the position of the light source, and the accuracy of the processed image very high

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