Optimal use of BitmapFactory.Options.inSampleSize for speed

Question

Thanks to Schermvlieger for asking this question on anddev.org,

I\'m just copying his question to SO as nobody replied on th

Answer 1

You've asked good questions , but it all depends on your needs and how much memory you use. I recommend checking out this link for many tips regarding bitmaps: http://developer.android.com/training/displaying-bitmaps/index.html .

In short , you should consider caching , downsampling , and using a good-enough bitmap format whenever you can.

Here's my answers to your questions:

1. Why not both? if you think there might be OOM , try to recycle old,unused bitmaps and then check again .

2. you can calculate the (estimated) size of the bitmap :

   width*height*bytesPerPixel

   where bytesPerPixel is usually 4 or 2 (depending on the bitmap format) .

3. Never used setImageURI , so I can't help you with that. I suggest downloading images in a background thread (using asyncTask is one way to do so) and showing them when it's ready.

4. If there are only a few that you know that won't take a lot of the memory , i guess it's ok. I still think caching could be better.