Whatever traditional wavelet edge detection technique was adopted

threshold was needed to filter candidate edge points for edge detection.However

threshold was obtained through experience presently

the best result was received after "cut and trial method" had been used repeatly

in addition

single-threshold calculation method can not accomplish accurate edge detection by now.These shortcomings restrict application of wavelet edge detection technique in practice.Aim at this problem

an algorithm of self-adaptive calculating double thresholds based on method of minimum interclass variance was proposed

and any parameter was not needing artificial setting .Fuzzy algorithm was adopted to link edge pixels

Theory and experiments showed that the algorithm was of validate and correct.