Pulse coupled neural network (PCNN) is a new generation of artificial neural networks and is characterized with adaptive image separation and adaptive image feature extraction. This paper presents a novel image feature, Space Adaptive Histogram(SAH), which is obtained from the output of PCNN stimulated by the image, to depict a histogram-like feature of an image but with both spatial and intensity features of the image. Then PCNN is utilized for adaptive image separation, and for SAH feature ext...