Using the computer vision technology and the machine servo system

the defects on the cylinder-bore's surface are detected automatically. The main problems solved in this paper are how to segment the image of the cylinder-bore; how to select threshold value; how to determine the object defects. To solve the problems

the value is chosen by the histogram average fitting method

the defects and the sizes are acquired by the regression formula. Experimental results show that the method has the features of high precision and high automation

which overcomes the weaknesses in traditional detecting method.