Aiming at all kinds of faults existed in artificial sampling visual method and measurement technology such as ultrasonic wave

electromagnetic wave applied for new type detection methods

in order to realize high speed online detection on flawed in auto brake cylinder wall

propose an image processing and defect detection method well meet the requirements based on digital image processing technology. Collect images on surface of parts needed to detect by CCD camera; process image by Matlab software

and extract edge; optimize edge by etching and expansion operation

again use tag of connected domain

judge types and characteristics of defect by calculating two physical quantities which are defect area and perimeter. The results show that the method can detect the cylinder inner-surface defects and can satisfy the requirement of rapid detection of defects basically.