以下算法是对rgb数据进行抽样，将数据在内容不变的情况下，降低数据的内存占用，方便应用处理和网络传输。

int scaleRGB(const unsigned char* src_img, unsigned char* dst_img, unsigned int src_width, unsigned int src_height, unsigned int dst_width, unsigned int dst_height)
{//bilinear interpolationif (!src_img || !dst_img){return -1;}if (!dst_width || !dst_height){return -2;}double x_ratio = (double)src_width / dst_width;double y_ratio = (double)src_height / dst_height;double aspect_ratio = 0.0f;int border_shift = 0;int h = 0, w = 0;int x0 = 0, x1 = 0, y0 = 0, y1 = 0;int dst_r = 0, dst_g = 0, dst_b = 0;if (x_ratio < y_ratio){aspect_ratio = x_ratio;border_shift = (int)((src_height - (int)(dst_height * aspect_ratio)) / 2);for (h = 0; h < dst_height; h++){for (w = 0; w < dst_width; w++){double src_h = border_shift + h * aspect_ratio;double src_w = w * aspect_ratio;x0 = (int)src_w;x1 = x0 + 1;y0 = (int)src_h;y1 = y0 +  + 1;int rx0y0 = src_img[3 *