Question

i m trying to implement some image filters fro that i use this code

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        imageView=(ImageView) findViewById(R.id.imgView);
        bgr = BitmapFactory.decodeResource(getResources(), R.drawable.test02);


        int A, R, G, B;
        int pixel;

        // scan through all pixels
        for(int x = 0; x < bgr.getWidth(); ++x) 
        {
            for(int y = 0; y < bgr.getHeight(); ++y) 
            {
                // get pixel color
                pixel = bgr.getPixel(x, y);
                A = Color.alpha(pixel);
                R = Color.red(pixel);
                G = Color.green(pixel);
                B = Color.blue(pixel);

                // increase/decrease each channel
                R += value;
                if(R > 255) { R = 255; }
                else if(R < 0) { R = 0; }

                G += value;
                if(G > 255) { G = 255; }
                else if(G < 0) { G = 0; }

                B += value;
                if(B > 255) { B = 255; }
                else if(B < 0) { B = 0; }

                // apply new pixel color to output bitmap
                bgr.setPixel(x, y, Color.argb(A, R, G, B));
            }
            System.out.println("x");
        }

        imageView.setImageBitmap(bgr);

    }

the problem is this is to slow is any other way to do it, OR make it faster..

Answer 1

You should read up about using a ColorMatrix. This matrix can perform exactly the operation you are performing manually. In your case, since you are just adding a constant value to each component, your matrix would have a = g = m = s = 1, and e = j = o = value, and the rest of your matrix would be zeroes.

Then you can use setColorFilter() to apply a ColorMatrixColorFilter to your ImageView.