Mat cv::imread(const String & filename, int flags = IMREAD_COLOR)
imwrite(filename, img[, params])
cvtColor(src, code[, dst[, dstCn]])
resize(src, dsize[, dst[, fx[, fy[, interpolation]]]])
boxFilter(src, ddepth, ksize[, dst[, anchor[, normalize[, borderType]]]])：Blurs an image using the box filter.
参考链接