中文说明：对低分辨率图像进行高斯滤波（消除噪点的影响），然后在滤波后的图像上估计出整数值位移量（相当于采用大图像块来估计大位移量），并以这个位移量估计值作为下一级匹配的初始值。接下来，采用双线性插值法对低分辨率图像进行采样，并对上采样图像进行高斯滤波（消除双线性插值法造成的数据不平稳性），然后在滤波后的图像上继续进行块匹配，获得亚像素精度的运动矢量。这样经过逐级上采样、高斯滤波和块匹配，可以获得要求的匹配精度。
English Description：
The low resolution image is filtered by Gaussian filter (to eliminate the influence of noise), and then the integer displacement is estimated on the filtered image (which is equivalent to using large image block to estimate large displacement), and the estimated displacement is used as the initial value of the next level matching. Next, the low resolution image is sampled by bilinear interpolation, and the up sampled image is filtered by Gaussian filter (to eliminate the data instability caused by bilinear interpolation), and then the block matching is continued on the filtered image to obtain the sub-pixel precision motion vector. In this way, through step-by-step up sampling, Gaussian filtering and block matching, the required matching accuracy can be obtained.