Decoding subsampled bitmaps in Android
- by hgpc
I decode bitmaps from the SD card using BitmapFactory.decodeFile. Sometimes the bitmaps are bigger than what the application needs or that the heap allows, so I use BitmapFactory.Options.inSampleSize to request a subsampled (smaller) bitmap.
The problem is that the platform does not enforce the exact value of inSampleSize, and I sometimes end up with a bitmap either too small, or still too big for the available memory.
From http://developer.android.com/reference/android/graphics/BitmapFactory.Options.html#inSampleSize:
Note: the decoder will try to fulfill
this request, but the resulting bitmap
may have different dimensions that
precisely what has been requested.
Also, powers of 2 are often
faster/easier for the decoder to
honor.
How should I decode bitmaps from the SD card to get a bitmap of the exact size I need while consuming as little memory as possible to decode it?
