Hang when trying to export Bitmap with Android. Memory Issue, array is too big

Question

I am trying to convert a image I take with drawView.getDrawingCache() When I run the code I don't get any errors, but it hangs with

11-20 15:43:14.208 28960-28960/edu.umass.ecs.chalkmaster3000 D/dalvikvm﹕ GC_FOR_ALLOC freed 285K, 8% free 19838K/21379K, paused 24ms, total 35ms

11-20 15:44:17.666 5502-5519/? W/ActivityManager﹕ Activity stop timeout for ActivityRecord{42e17c78 edu.umass.ecs.chalkmaster3000/.MainActivity}

Below is the code I am running

public Bitmap grayToBlackWhite(Bitmap b)
{
    Bitmap chanagebleBitMap = b.copy(Bitmap.Config.ARGB_8888, true);
    int[] pixels = new int[1];
    if(b != null){
       int picw = chanagebleBitMap.getWidth();
       int pich = chanagebleBitMap.getHeight();
       pixels = new int[picw*pich];
       chanagebleBitMap.getPixels(pixels, 0, picw, 0, 0, picw, pich);
        int R, G, B,Y;

        for (int y = 0; y < pich; y++){
            for (int x = 0; x < picw; x++)
            {
                int index = y * picw + x;
                R = (pixels[index] >> 16) & 0xff;     //bitwise shifting
                G = (pixels[index] >> 8) & 0xff;
                B = pixels[index] & 0xff;

                if(((R+G+B)/3)>128)
                R=G=B=150;
                else
                R=G=B=0;

                //R,G.B - Red, Green, Blue
                //to restore the values after RGB modification, use
                //next statement
                pixels[index] = 0xff000000 | (R << 16) | (G << 8) | B;

               chanagebleBitMap.setPixels(pixels, 0, chanagebleBitMap.getWidth(), 0, 0, chanagebleBitMap.getWidth(), chanagebleBitMap.getHeight());
            }
        }
    }

    return chanagebleBitMap;

}

The line that causes the issue is the setPixels call.

I have no experience with this type of problem, any hints or help would be much appreciated. Thanks!

After reading your response I went and took a look with the android debug monitor. Here is a picture of what I am seeing.

Nothing seems to be too out of check, does it to you?

I did more more debugging. The width and height of my original picture I am trying to convert is 700 by 886 pixels. When I create the int array it is 620200 in size! Multiply this by 4 (since each int is 4 bytes) and the size is 2 gigs!?!?

If this is correct, I understand why I am getting the memory error, but how would I go about doing what I need if this is the case?

As always, Thanks!

Answer 1

From: http://developer.android.com/tools/debugging/debugging-memory.html

GC_FOR_MALLOC A garbage collection caused because your app attempted to allocate memory when your heap was already full, so the system had to stop your app and reclaim memory.

So try to optimize your memory usage.