Drawable temp = imageview.getDrawable();
Drawable temp1 = mContext.getResouce().getDrawable(R.drawable.icon);

Bitmap tmpBitmap = ((BitmapDrawable)temp).getBitmap();
Bitmap tmpBitmap1 = ((BitmapDrawable)temp1).getBitmap();

if(tmpBitmap.equals(tmpBitmap1) {
...
}