Native-Floyd-Steinberg-Dithering

Android library for floyd-steinberg dithering on bitmap using JNI/Cmake

Why FSD

For those who don't know the purpose of Floyd-Steinberg algorithm, it is a algorithm to turn color image to black and white(NOT GRAYSCALE).

When would we use this? Well, for those e-ink displays like Amazon Kindle, they can't display color images, and just black and white would still look bad, this is when this algorithm is usful.

I have tried using just java to run the algorithm, but it is slow. Not a good idea to run on main thread. This library is small and easy to use.

Using FSD

Setup

	allprojects {
		repositories {
			...
			maven { url 'https://jitpack.io' }
		}
	}

Dependencies

	dependencies {
	        compile 'com.github.jeffreyliu8:Native-Floyd-Steinberg-Dithering:0.0.5'
	}

A quick example is shown below:

Bitmap original = BitmapFactory.decodeResource(getResources(), R.drawable.lena);
Bitmap fsBitmap = Utils.floydSteinbergDithering(original);

And for just black and white image:

Bitmap bwBitmap = com.askjeffreyliu.floydsteinbergdithering.Utils.binaryBlackAndWhite(original);

And for gray-scale image(This is just a simple java function):

Bitmap grayBitmap = com.askjeffreyliu.floydsteinbergdithering.Utils.toGrayscale(original);

Requirements

Requires a minimum SDK version of 14