The invention relates to a paper defect detection method based on the local brightness invariance priori, which comprises the following steps of 1, photographing the surface of paper to be detected byusing a color area array camera, and capturing a frame of
color image with a pixel format of RGB components; 2, carrying out nonlinear graying operation on all pixels of the
color image in the
mask of the
convolution template by using a
convolution template with local brightness invariance priori, and finally obtaining pixels corresponding to the
convolution window; according to the 1*1 convolution operation and the 3 * 3 convolution operation, obtaining two
gray level images respectively; 3, carrying out corresponding position pixel division on the two
grayscale images to obtain a grayscaleimage; 4, performing 3 * 3 Fourier convolution operation on the
grayscale image; 5, performing gradient morphological operation on an operation result; 6, performing
thresholding processing to obtaina paper defect detection result. According to the present invention, a common
light source and an area array camera can be used for detecting paper defects, and a detection
system is low in complexity, high in accuracy and low in cost.