A flat-field calibration method of a linear array camera

Abstract

The invention discloses a flat field correction method of a linear array camera suitable for field working conditions. The method includes: obtaining an original correction coefficient matrix by shooting an initial gray value matrix of an initial row of a screen to be inspected; obtaining an original gray value matrix by scanning and photographing the gray value image of the screen to be inspectedby the linear array camera; multiplying the original gray value matrix by the original correction coefficients of the corresponding columns to obtain a preliminarily corrected gray value matrix; dividing the gray value of each pixel in the preliminarily corrected gray value matrix by the median value of the row to determine the pixel response non-uniformity coefficient of the initial row in the pixel matrix of the screen to be inspected; obtaining effective flat-field correction coefficients to correct the gray-scale image taken by the linear array camera. The method of the technical scheme of the invention aims at the problems that the current flat field correction method of the linear array camera is difficult to adapt to the difference of the working environment and the precision is not high, and under the actual working condition, the flat field correction of the linear array camera is carried out through the combination of the optics and the algorithm, which has good adaptabilityand high precision.

Description

technical field [0001] The invention belongs to the technical field of flat-field correction of line-scan cameras, in particular to a correction technology before panel defect detection based on line-scan cameras, and in particular relates to a line-scan camera flat-field correction method suitable for on-site working conditions. Background technique [0002] In machine vision, according to the arrangement of sensor pixels, cameras can be divided into area scan cameras and line scan cameras. Area array cameras, that is, the target surface of the sensor is a surface, are very commonly used. For a line scan camera, the sensor pixels are distributed in a "line" shape, that is, the pixels are only arranged in one row. Compared with area scan cameras, line scan cameras have higher precision. The field of view taken by the line array camera is a slender strip, which is mostly used for scanning inspection, scanning the screen to be inspected moving at a constant speed, and synthe...

AI Technical Summary

Problems solved by technology

The method of the technical solution of the present invention aims at the problem that the current flat field correction method of the line array camera is difficult to adapt to the difference in the working environment and the accuracy is not high. Field correction, good adaptability and high precision

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