openCV记录3——图像像素的读写操作

void QuickDemo::pixel_visit_demo(Mat &image)
{
int w = image.cols;
int h = image.rows;
int dims = image.channels();
/* for (int row = 0; row < h;row++)
{
for (int col = 0; col < w;col++)
{
if (dims == 1)//单通道灰度图像
{
int pv = image.at(row, col);
image.at(row, col) = 255 - pv;
}
if (dims == 3) //彩色图像
{
Vec3b bgr = image.at(row, col); //一次性获取3个值
image.at(row, col)[0] = 255 - bgr[0];
image.at(row, col)[1] = 255 - bgr[1];
image.at(row, col)[2] = 255 - bgr[2];
}
}
}*/

for (int row = 0; row < h; row++)
{
	uchar * current_row = image.ptr<uchar>(row) ;

	for (int col = 0; col < w; col++)
	{
		if (dims == 1)//单通道灰度图像
		{
			int pv = *current_row;
			*current_row ++ = 255 - pv;
		}
		if (dims == 3) //彩色图像
		{
			*current_row++ = 255 - *current_row;
			*current_row++ = 255 - *current_row;
			*current_row++ = 255 - *current_row;
		}
	}
}
imshow("像素读写演示", image);

}