How to fill bitmap object with color in Android

I'm working on Android game and there are some problem appear I want to fill a color on bitmap object but can not I tried bitmap.setPixel but my Image is PNG format (like a circle or unsharp, surrounded with transparent color) and android can not getHeight() or getWidth(), ie

ImageView i = new ImageView(mContext);
Bitmap bMap = BitmapFactory.decodeResource(this.mContext.getResources(), mImageIds[position]);


//        for(int i1 = 0; i1 < bMap.getHeight();i1++)
//         for(int j = 0; j < bMap.getWidth(); j ++)
//          bMap.setPixel(i1, j, Color.RED);   //can not set

    i.setImageBitmap(bMap);        
    i.setLayoutParams(new Gallery.LayoutParams(150, 100));
    i.setScaleType(ImageView.ScaleType.FIT_XY);        
    i.setBackgroundResource(mGalleryItemBackground);
    i.setBackgroundColor(Color.TRANSPARENT);