The invention provides an automatic optic 
inspection method for surface defects of 
metal cylindrical workpieces and belongs to the automatic optic inspection methods. The automatic optic 
inspection method is particularly suitable for detecting surface defects of special 
metal cylindrical workpieces and comprises the following steps: a 
linear array CCD acquires the unrolled images of a 
metal cylindrical workpiece, the local binary pattern (LBP) and the 
local variance (LVAR) are combined, that is, the image variance intensity serves as the 
weight value to adjust the local 
texture extraction and measurement result of the LBP, not only the LBP 
texture space structure mode but also the texture intensity contrast mode is drawn into consideration, finally, the photoelectric image fault features of metal cylinders are accurately extracted, the sizes, the positions, the ranges, the severities and the like of the defects are determined, and the automatic intelligent detection of the workpiece 
production quality is realized. Therefore, nonuniform lighting caused by the metal materials of the workpieces per se is avoided, the accuracy in detecting tiny defects is improved, the misjudgement rate is lowered, and automatic optic inspection of the metal cylindrical workpieces is achieved.