public
class
NativeBlurFilter
extends Object| java.lang.Object | |
| ↳ | com.facebook.imagepipeline.nativecode.NativeBlurFilter |
Class Overview
A fast native blur filter. See iterativeBoxBlur(Bitmap, int, int)
Summary
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| NativeBlurFilter() | |||||||||||
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| static void |
iterativeBoxBlur(Bitmap bitmap, int iterations, int blurRadius)
This is a fast, native implementation of an iterative box blur.
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From class
java.lang.Object
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Public Constructors
public NativeBlurFilter ()
Public Methods
public static void iterativeBoxBlur (Bitmap bitmap, int iterations, int blurRadius)
This is a fast, native implementation of an iterative box blur. The algorithm runs in-place on the provided bitmap and therefore has a very small memory footprint.
The iterative box blur has the nice property that it approximates the Gaussian blur very quickly. Usually iterations=3 is sufficient such that the casual observer cannot tell the difference.
The edge pixels are repeated such that the bitmap still has a well-defined border.
Asymptotic runtime: O(width * height * iterations)
Asymptotic memory: O(radius + max(width, height))
Parameters
| bitmap | The targeted bitmap that will be blurred in-place. Each dimension must not be greater than 65536. |
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| iterations | The number of iterations to run. Must be greater than 0 and not greater than 65536. |
| blurRadius | The given blur radius. Must be greater than 0 and not greater than 65536. |