一些几何变换 傅立叶变换 边缘提取 高通、低通、中值滤波器 一些效果变换：比如颜色变换，灰度变换，颜色变换等-Transformation Fourier transform of some geometric edge extraction high-pass, low pass, median filter transform some results: for example, color conversion, grayscale conversion, color conversion