On detection of cottonseed perimeter based on self-adaptive freeman code

To detect broken cottonseeds in cottonseeds real-time detection system,edge must be extracted and perimeter be calculated.Traditional methods of edge extraction such as Sobel,Robert,mathematical morphology and wavelet transformation are limited in real-time system due to their slow processing rate.Freeman code is one of the methods of edge description.The difference between Freeman code and other methods is that Freeman code gives the curvature and feature points and so on through relative techniques.Meanwhile,the curvature and feature points are essential to image compression and image restoration.The method of Freeman code in edge extraction was applied to cottonseed perimeter calculation.By comparison with Sobel and Robert,Freeman code method is single-pixel and proved to be quick and precise in calculating perimeter,especially in real time system.