Converting `BufferedImage` to `Mat` in OpenCV

Question

How can I convert a `BufferedImage` to a `Mat` in `OpenCV`? I'm using the JAVA wrapper for `OpenCV`(not JavaCV). As I am new to `OpenCV` I have some problems understanding how `Mat` works. I want to do something like this. (Based on Ted W. reply): ``` BufferedImage image = ImageIO.read(b.getClass().getResource("Lena.png")); int rows = image.getWidth(); int cols = image.getHeight(); int type = CvType.CV_16UC1; Mat newMat = new Mat(rows, cols, type); for (int r = 0; r < rows; r++) { for (int c = 0; c < cols; c++) { newMat.put(r, c, image.getRGB(r, c)); } } Highgui.imwrite("Lena_copy.png", newMat); ``` This doesn't work. `Lena_copy.png` is just a black picture with the correct dimensions.

Accepted Answer

I also was trying to do the same thing, because of need to combining image processed with two libraries. And what I’ve tried to do is to put `byte[]` in to `Mat` instead of RGB value. And it worked! So what I did was:

1.Converted `BufferedImage` to byte array with:

```
byte[] pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
```

2. Then you can simply put it to Mat if you set type to CV_8UC3

```
image_final.put(0, 0, pixels);
```

Edit: Also you can try to do the inverse as on this answer

Converting `BufferedImage` to `Mat` in OpenCV

Solution

Problem