Source link: https://github.com/PGSSoft/uglyfier

Uglyfier for Android

Gradle script for downsizing graphical assets in development builds

Problem

Usually you don't care how big the deployed APK is. However, if you are using metered connection and remote ADB, it would be good idea to build possibly smallest APK file.

Solution

Uglyfier for Android is a gradle script which will shrink all image resources in your application during build. It will look ugly, but image files will be 10 times smaller. Ninepatch (9-patch) PNGs are fully supported, with transparency preserved!

Installation

Install ImageMagick
Download uglyfy.gradle and save it to application directory (where build.gradle live)

Create new buildType, i.e. "uglyfied". You can define it to inherit existing one:

buildTypes {

  debug {

debuggable true
  
}

uglyfied.initWith(buildTypes.debug)
  uglyfied{

}

Add following snippet to your build.gradle, adjusting all three variables.

ext {

  UglyfierSourceVariant

= 'debug'
  // this is the source build type
  UglyfierDestinationVariant = 'uglyfied'  // this is the target, uglyfied build type

// provide path to Imagemagick here
  // (or remove this line and set IMAGEMAGICK_EXECUTABLE environment variable
  UglyfierImagemagickPath = 'c:/Program Files/ImageMagick-7.0.1-10-portable-Q16-x86/magick.exe' //sample value for Windows
  //UglyfierImagemagickPath = '/usr/bin/convert' //sample value for Linux 
}
 apply from: 'uglyfy.gradle'

Try to build new "uglyfied" variant.

What will happen?

During build following events will take place:

Image files (PNG, JPG, JPEG) from "main" resource directory will be copied to "uglyfied" resource directory, then downsized.
Image files from source variant (i.e. "debug") will be also copied to "uglyfied" resource directory, then downsized.
Any extra resource files from source variant (i.e. "debug") will be also copied to "uglyfied" resource directory.

How the downsizing works?

JPEG files are heavily recompressed, with target quality=5. Compression artifacts are expected.

PNG files are downsized to 10% of size, then scaled back. Big pixel blocks are expected. Ninepatch (9-patch) files are fully supported, 1-pixel frame is preserved! (as well as transparency)

Files smaller than 5KB are skipped.