Abstract: To enhance the reliability and automation of stitch length measurement,a stitch length measuring system through processing the scanned image based on MatLab was introduced.First,by extracting the features reflecting the stitch length with FFT(Fast Fourier Transform) and specific processing,the 2-D stitch length was measured,and then,the 3-D stitch length was calculated automatically according to regression analysis.Experiments demonstrate that no notable difference is found of the data obtained between the system and manual measurement.