Comparison of various image loading and cache technologies on the Android platform.

1. Cache images in Android
Ali Muzaffar

2. The goal
 Async download and cache images from the inter-web.
 Should be easy to maintain.
 Should handle large hi-res images.
 Should be as efficient as possible.
 Low memory usage.
 Fast display of images.
 Optionally, image transformations.

3. The contenders
 Bitmap Cache http://developer.android.com/training/displaying-bitmaps/cache-
bitmap.html
 Google Volley https://android.googlesource.com/platform/frameworks/volley
 Chris Bane’s Android-BitmapCache https://github.com/chrisbanes/Android-
BitmapCache
 Wu Man’s AndroidImageLoader https://github.com/wuman/AndroidImageLoader/
 Android-Query (AQuery) https://code.google.com/p/android-query/
 Picasso http://square.github.io/picasso/

4. Comparison
Google Google Volley Android-
BitmapCache
Android-
ImageLoader
AQuery Picasso
Ease of use Hard Easy Normal Easy V. Easy V. Easy
Loading image No Yes No Yes Yes Yes
Error image No Yes No Yes Yes Yes
Efficiency Good Excellent V. Good V. Good Excellent Excellent
Image Transform No No No Sort of Yes Yes
Other features No Sort of No No Yes Yes
Hi-Res Images Normal Excellent Good Good Excellent Excellent
Overall 5 2 4 3 1 1

5. Notes on Google Code
 PRO
 Lots of control.
 You can get most of the code from Google.
 Compatible with older Android versions.
 CONS
 Lots of coding required.
 You are responsible for caching on flash or in memory.
 No transformation controls.

6. Google Volley
 PROS
 Very efficient.
 Innovative caching of images so they load in batches.
 Backward compatible.
 Very little code required.
 Built with parallel operations in mind.
 Great support for cancelling network operations.
 CONS
 No image transformation support.
 Holds the entire server response in memory, if the server response is 1MB or
greater this could be an issue.
 No built in prefetching (though you can code it).
 Very little Documentation (mostly Javadoc and a Video).

7. Notes on Chris Bane’s Android-
BitmapCache
 PROS
 Efficient.
 Uses reliable libraries (Jake Whartons LruCache & CacheableImageView).
 Compatible with old versions.
 Provides implementation for downloading images from the network.
 Good samples.
 Frequent updates.
 CONS
 Too many libraries.
 No image transformation support.
 Does not (by default) support downloading images from the Network.
 No documentation.
 Not fast enough.
 Need to extend Application.

8. Wu Man’s AndroidImageLoader
 PROS
 Efficient.
 Image placeholders.
 Supports downloading of images, error handling.
 Good documentation & samples.
 Self contained.
 CONS
 Recycling views old image was visible for a second.
 Min SDK 7.
 Not updated in 8 months.
 Not fast enough.
 Need to extend Application.

9. AQuery (Android-Query)
 PROS
 Fast and very efficient (best in my tests by far).
 Single jar to include (200KB).
 Placeholders, image transformation, error handling etc..
 Amazing set of features.
 Backward compatible.
 App provided which shows off all the features and the source code used.
 CONS
 Have to use AQuery syntax.
 200KB for full or 100KB for core. Big?

10. Picasso or Android
Disclaimer: Not Tested for Efficiency
 PROS
 Fast & Efficient.
 Easy to use.
 Self contained single jar (95KB).
 Placeholders, image transformation, error handling etc.
 Image specific features, including cropping.
 CONS
 Has it’s own syntax.
 Decent documentation but could be better.
 95KB. Big?

11. Question
 Do you really need to download images from the inter-web?