Java – Crop and resize images in Android

I’m reading an image from disk and displaying it in one row in a ListView. The image file is larger than the file that needs to be displayed in the ImageView of the row. Since I need to cache bitmaps in RAM for faster access, I want them to be only as large as the ImageView (85×85 dip).

Now I’m reading the document

bitmap = BitmapFactory.decodeFile(file);

The ImageView is responsible for scaling and cropping

android:scaleType=”centerCrop”

As far as I can tell, this is keeping the entire bitmap in memory (because I cache it XD), which is bad

How can I remove this responsibility from ImageView and crop + zoom when loading the file? All bitmaps will be displayed at an 85×85 inclination and require “centerCrop”

You can find out the dimensions of the image before loading, cropping, and scaling:

BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;

Bitmap bmo = BitmapFactory.decodeFile(file.getAbsolutePath(), options);

Then load it at sample size:

...
options.inSampleSize = 1/2;
bmo = BitmapFactory.decodeFile(file.getAbsolutePath(), options);

...
 = Bitmap.createScaledBitmap(bmo, dW, dH, false);

Don’t forget to recycle temporary bitmaps, otherwise you’ll get OOME.

bmo.recycle();