In my application I load a couple of images from JPEG and PNG files. When I place all those files into assets directory and load it in this way, everything is ok:
You must not depends on the GC to recycle your bitmap memory. You must clearly recycle the bitmap when it is not needed.
See the Bitmap method:
void recycle() Free up the memory associated with this bitmap's pixels, and mark the bitmap as "dead", meaning it will throw an exception if getPixels() or setPixels() is called, and will draw nothing.