DownUpSampling_ByFactor2

代码说明：

  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 to achieve a 2-factor image upsampling and downsampling function. Down-sampling (with using the averaging filter) and do not use smoothing filter (without using the averaging filter) are two ways to use the smoothing filter. Upsampling including the pixels copied directly (pixel replication method) and linear interpolation (bilinear interpolatoin method) two methods. Down-sampling method and liters a total of four combinations of sampling methods. The program is running, it shows a picture of an original picture and four results. Picture 1 original picture. Photo 2. Smoothing filter downsampling & the pixel directly copied liter sample. Photo 3. Smoothing filter downsampling & the linear interpolation liter sampling. Picture 4. Smoothing filter down-sampling & the pixels directly copied liter sampling. Picture 5. Use smoothing filter down-sampling & the linear interpolation liter sampling.)