Opto electric hybrid processing has made significant advance in implementing a great number of pattern recognition and classification algorithms and systems,especially for 2 D patterns.And real time image pre processing,including target detection and location,is a necessary stage for their applications.Based upon binary morphological erosion,a quick method of target detection and location is presented in this paper.Two morphological structuring elements are constructed to modify the morphological erosion.The basic algorithm is given.Also the experiment of image pre processing for a real time multi targets recognition neural network system is described,which shows that target detection and location of the binary image by thresholding the grayscale image grabbed by CCD camera are implemented successfully by the way putted forward in this paper.