A detection method for surface defects of curved glass by spatially encoded light field

Abstract

The invention discloses a detection method for curved glass surface defects by a spatial encoding optical field. The detection method comprises the following steps that: according to a selected encoding element number and the size of a first window, generating a one-dimensional pseudorandom sequence with window characteristics; adopting a diagonal method to construct a two-dimensional pseudorandomsequence M; according to the characteristic point distribution of the field of view of a sample to be detected, determining the size of an M' array; through a vertical splicing method and a diagonalsplicing method, converting an M array into the M' array; enabling different encoding elements to correspond to different geometric patterns, and converting the M' array into M' array encoding; and converting the M' array encoding into the encoding image of an object surface to realize the defect detection of the curved glass. By use of the detection method, a matrix M is converted into an M' array, a difference between the line number and the row number of the M' array can be reduced, and the resolution of the encoding image is improved. By use of the detection method, the vertical splicing way and the diagonal splicing way can be adopted to guarantee splicing efficiency, and meanwhile, accuracy generated when the defect of the sample to be detected is identified is improved.

Description

technical field [0001] The invention belongs to the field of defect detection, and more specifically relates to a method for detecting surface defects of curved glass with a spatially coded light field. Background technique [0002] According to the coding strategy, the existing structured light coding methods can be divided into three categories: temporal coding, direct coding and spatial coding. The time coding method projects multiple patterns sequentially in chronological order, and each projection generates a code value for each pixel, thereby generating a code word corresponding to each pixel; the direct coding method uses the characteristics of projected light to directly code each pixel of the coding pattern. For spatial coding, only one coding pattern needs to be projected, and the adjacent pixel information is used to generate a codeword. [0003] Although the time coding method has the advantages of easy implementation, high spatial resolution, and high 3D measur...

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Problems solved by technology

[0005] Aiming at the defects of the prior art, the object of the present invention is to provide a method for detecting defects on the curved glass surface by a spatially encoded light field, aiming at solving the problem of the existing M-arrays pattern encoding due to limitations of hardware and spatial encoding methods. The problem of low resolution of the encoding pattern after the 3D reconstruction of the object

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