这个matlab程序通过标准的hough变换，并指定圆半径的情况下，在二值图像中检测圆。-The matlab program through standard hough transform, and specify the radius, the two values in the detection of circular images.

this circle detection in binary image-this is circle detection in binary image

this code is one of robust codes in circle detection

这是一个关于齿轮的齿顶圆和齿根圆半径的计算程序，先将图片预处理和二值化，然后进行边缘检测求出圆心，最后用平均法求出半径。-This is an addendum on the gear tooth root radius circle and the calculation procedure, the first image preprocessing and binarization, edge detection and then find the center of a circle,

Edge detection result should be enhanced using linear method like Median filter to remove the garbage around the pupil to gain clear pupil to determine perfect centre. Get the centre of the pupil by counting the number of black pixels (zero value