OpenCV camera image shows bluish

Question

I'm using the below code to get an image from the camera, but the camera image shows colours differently.

public Mat mat = new Mat();
private BufferedImage img;
private byte[] dat;

    public void getSpace(Mat mat) {
            this.mat = mat;
            int w = mat.cols(), h = mat.rows();
            if (dat == null || dat.length != w * h * 3)
                dat = new byte[w * h * 3];
            if (img == null || img.getWidth() != w || img.getHeight() != h || img.getType() != BufferedImage.TYPE_3BYTE_BGR)
                img = new BufferedImage(w, h, BufferedImage.TYPE_3BYTE_BGR);
        }

        public BufferedImage getImage(Mat mat) {
            getSpace(mat);
            mat.get(0, 0, dat);
            img.getRaster().setDataElements(0, 0, mat.cols(), mat.rows(), dat);
            return img;
        }

looks like red and blue channels are interchanged (green light is still green but blue light is red and redish areas are bluish) — Micka, Apr 26 '16 at 20:39
@Micka no it isn't public, I included the fields now as well. — PRCube, Apr 26 '16 at 20:44

score 1 · Answer 1 · edited May 23 '17 at 11:58

1

Maybe your images is of type RGB instead of BRG? In that case you would have exchanged red and blue colour. Try changing TYPE_3BYTE_BGRinto TYPE_3BYTE_RGB

[EDIT] Sorry, I am only on the Python side of OpenCV. What has happend is that you accidentially switched channels B and R (1st and 3rd layer of your image matrix), you need to switch this back. Exchange it in the matrix if necessary.

That link might help: Converting BufferedImage to Mat in opencv

[EDIT2] Have a look at the comment of Micka below

edited May 23 '17 at 11:58

Community

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answered Apr 26 '16 at 20:27

tfv

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unfortunately, TYPE_3BYTE_RGB doesn't exist. the only rgb that exists is TYPE_INT_RGB which doesn't work. – PRCube Apr 26 '16 at 20:31
1

you can try to convert the opencv mat from rgb to bgr. c++ code would be cv::cvtColor (mat,mat, CV_RGB2BGR) maybe you xan convert that? – Micka Apr 26 '16 at 20:48

OpenCV camera image shows bluish

1 Answers1