C++把图片从BGR转到RGB

//fcount图片的个数
for (int b = 0; b < fcount; b++) {
				cv::Mat img = images[b];
				if (img.empty()) continue;
				//resize()缩放图片
				cv::Mat pr_img = preprocess_img(img); // letterbox BGR to RGB
				int i = 0;
			//BGR-RGB
				for (int row = 0; row < INPUT_H; ++row) {
					uchar* uc_pixel = pr_img.data + row * pr_img.step;
					for (int col = 0; col < INPUT_W; ++col) {
						data[b * 3 * INPUT_H * INPUT_W + i] = (float)uc_pixel[2] / 255.0;
						data[b * 3 * INPUT_H * INPUT_W + i + INPUT_H * INPUT_W] = (float)uc_pixel[1] / 255.0;
						data[b * 3 * INPUT_H * INPUT_W + i + 2 * INPUT_H * INPUT_W] = (float)uc_pixel[0] / 255.0;
						uc_pixel += 3;
						++i;
					}
				}
				}