Spritesheet programmatically cutting: best practices

Question

I have a big spritesheet (3808x1632) composed by 42 frames. I would present an animation with these frames and I use a thread to load a bitmap array with all the frames, wit

Answer 1

Thanks to stevehb for the suggestion, I finally got it:

for (int i = 0; i < TotalFramesTeapotBG; i++) {
    xStartTeapotBG = (i % framesInRowsTeapotBG) * frameWidthTeapotBG; 
    yStartTeapotBG = (i / framesInRowsTeapotBG) * frameHeightTeapotBG;
    Bitmap bmFrame = Bitmap.createBitmap(frameWidthTeapotBG, frameHeightTeapotBG, Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(bmFrame);  
    Rect src = new Rect(xStartTeapotBG, yStartTeapotBG, xStartTeapotBG+frameWidthTeapotBG, yStartTeapotBG+frameHeightTeapotBG); 
    Rect dst = new Rect(0, 0, frameWidthTeapotBG, frameHeightTeapotBG);  
    c.drawBitmap(framesBitmapTeapotBG, src, dst, null);         
    mVectorTeapotBG.add(bmFrame);
}

The computation time falls incredibly! :)