AllBecomesGood's profile - activity

No worries, you've helped me plenty! It is odd as to why their Sepia Matrix is rotated, but I will be investigating tomorrow :)

This looks promising for Sepia, but absolutely not for my Protan Matrix. Why is yours left-rotated? Or do I completely misunderstand how the OpenCV Matrix is structured? I'm gonna be off soon, so might be looking at this again tomorrow.

If you are on Stack Overflow and want to get points here is the Thread I made there: http://stackoverflow.com/questions/38...

Didn't see your reply until it refreshed after my answer, will check.

Hi and thank you so much! I think this is doing exactly what I need. I ran into problems with applying the Sepia filter (it just turns the image into shades of green). I had this problem before, as I ran the intrinsic over Bitmap, so I don't think there's a problem in your code. I've marked your answer, but maybe you're a genius for this too:

ScriptIntrinsicColorMatrix colorMatrix = ScriptIntrinsicColorMatrix.create(mRS, element);
final Matrix4f mSepia = new Matrix4f(new float[]{
                0.189f, 0.769f, 0.393f, 0f,
                0.168f, 0.686f, 0.349f, 0f,
                0.131f, 0.534f, 0.272f, 0f,
                0.000f, 0.000f, 0.000f, 1f
        });
colorMatrix.setColorMatrix(mSepia); 
colorMatrix.forEach(inputAllocation, outputAllocation);

I am making an Android app to simulate colourblindness. It takes a camera feed and manipulates at runtime.

• My question:

I have an OpenCV Mat object rgba, containing all Pixels of a given frame with red, green, blue and alpha (rgba) values. To speed up processing I'd like to use Renderscript, but when I convert that Mat rgba to Bitmap I lose about 5 fps, making any speedgain by Renderscript pointless. So I would like to know a way of placing the contents of Mat rgba into an Allocation that I can give to Renderscript, where I then just do Matrix multiplication for it all and return it.

• What I tried:

  • Converting Mat to Bitmap and then give to Renderscript, which works but is way too expensive (minus ~5 fps).
  • Allocation aName2 = Allocation.createFromString(mRS, rgba.dump(), 3); // this just shows i am desperate ;(

• In case you're interested what I am doing at the moment:

I based my app on the imagemanipulations example provided by OpenCV, specifically the Sepia filter option.

In onCameraViewStarted{} I set a Kernel such as for example the Sepia Kernel:

        // Fill sepia kernel
        mSepiaKernel = new Mat(4, 4, CvType.CV_32F);
        mSepiaKernel.put(0, 0, /* R */0.189f, 0.769f, 0.393f, 0f);
        mSepiaKernel.put(1, 0, /* G */0.168f, 0.686f, 0.349f, 0f);
        mSepiaKernel.put(2, 0, /* B */0.131f, 0.534f, 0.272f, 0f);
        mSepiaKernel.put(3, 0, /* A */0.000f, 0.000f, 0.000f, 1f);

Then in onCameraFrame OpenCV places the frame into a Mat and the filter is run over it, causing it to have this yellowish tint.

public Mat onCameraFrame(CvCameraViewFrame inputFrame) {  
Mat rgba = inputFrame.rgba(); 
Core.transform(rgba, rgba, mSepiaKernel); 
return rgba;  
}

I have this running for Protan, Deutan and Tritan and on the S7 edge I get 10 fps. This is okayish, but as soon as we put the app on an older phone it becomes incredibly slow. Hence I would like to do what Core.transform() does in Renderscript instead.