Abstract: In order to solve the proplem of low image contrast and high diffculty of extracting independently for fringe image in photoelstic coatings measurement,an efficient approach is proposed to eliminate image noise based on RGB feature space before extracting fringe isochromatic and isoclinic,in which a modified vector median filter is given to filter color image noise without destroying undefiled pixel information.Through analyzing the color characteristics of fringe image.the R-G feature operator is adopted to extract fringe isochromatic which is transformed to binary image.Achromatic threshold is adopted to obtain the pure isoclinic in binary image.The results show that color image processing of photoelastic coating fringe pattern based on RGB feature space is more efficient than gray scale image processing for noise reduction and fringe image extraction.