说明：  该代码实现了以2为因子的图像升采样和降采样功能。 降采样包括使用平滑滤波器(with using the averaging filter)和不使用平滑滤波器(without using the averaging filter)两种方法。 升采样包括像素点直接复制(pixel replication method)和线性插值(bilinear interpolatoin method)两种方法。 降采样方法和升采样方法共有4种组合。程序运行后，给出了一个原始图片和四个结果图片。 图片1.原始图片。 图片2.平滑滤波器降采样&像素点直接复制升采样。 图片3.平滑滤波器降采样&线性插值升采样。 图片4.不使用平滑滤波器降采样&像素点直接复制升采样。 图片5.不使用平滑滤波器降采样&线性插值升采样。
(The code implements a factor of 2 liters of sampling and down-sampling the image function. Downsampling including the use of smoothing filter (with using the averaging filter) and does not use smoothing filter (without using the averaging filter) in two ways. L sample includes direct copying pixels (pixel replication method) and linear interpolation (bilinear interpolatoin method) in two ways. Downsampling and upsampling method There are four combinations of methods. After the program runs, gives a picture of the original image and the four results. Picture 1 original picture. Picture 2. Smoothing filter downsampling & Pixel copied directly liter sample. Picture 3. Smoothing filter downsampling & linear interpolation upsampling. Picture 4 without using a smoothing filter downsampling & Pixel copied directly liter sample. Picture 5. Downsampling does not use smoothing filter & linear interpolation upsampling.)