用c语言在window窗口实现验证码图片，实现字符位置等随机，背景噪声功能-Using c language in the code window picture window, the location of the realization of random characters, the background noise function

c语言实现 功能是实现图象的平滑（去噪声），锐化-c language function is to achieve a smooth image (to noise), sharpening