Recycling Bitmap does not free memory

I have an `Activity` in a `TabHost` with 3 other activities. Hence, these are always alive (or in "on pause" state). The first activity has four different images (~250kb each) and they are retrieving a lot of memory (around 80MB. Just to point out, I load the minimum size needed for the screen and I'm using `layout_weight` if that helps), so I want to minimize the amount of memory which is needed. I already tried to delete the images on the `OnPause` state and set them again on `OnResume`, but I didn't have luck, this is one example of what I was trying to do: ``` imageView.Drawable.Callback = null; ((BitmapDrawable)imageView.Drawable).Bitmap.Recycle(); imageView.Drawable.Dispose(); imageView.SetImageDrawable(null); imageView.SetImageBitmap(null); GC.Collect(); ``` I don't know if deleting the `Bitmap` on `OnPause` is the best strategy, but it should work. I don't understand why the `ImageView` isn't collected by the GC (since there are not external references) EDIT This is how I'm loading the images. It doesn't work even if I put the images on the xml file. Besides, I don't care this code, I just want to dispose the bitmaps. ``` void SetBackgroundImages(int imageId, int resId, float width, float height) { var imageView = FindViewById<ImageView>(imageId); using (var bitmap = DecodeSampledBitmapFromResource(Resources, resId, width, height)) imageView.SetImageBitmap(bitmap); } public static Bitmap DecodeSampledBitmapFromResource(Resources res, int resId, float reqWidth, float reqHeight) { var options = new BitmapFactory.Options {InJustDecodeBounds = true}; using (var b = BitmapFactory.DecodeResource(res,resId,options)){} options.InSampleSize = CalculateInSampleSize(options, reqWidth, reqHeight); options.InJustDecodeBounds = false; return BitmapFactory.DecodeResource(res, resId, options); } ```