Here you can find the source of blur(Bitmap bitmap)
public static Bitmap blur(Bitmap bitmap)
//package com.java2s; import android.graphics.Bitmap; public class Main { public static Bitmap blur(Bitmap bitmap) { int iterations = 1; int radius = 8; int width = bitmap.getWidth(); int height = bitmap.getHeight(); int[] inPixels = new int[width * height]; int[] outPixels = new int[width * height]; Bitmap blured = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); bitmap.getPixels(inPixels, 0, width, 0, 0, width, height); for (int i = 0; i < iterations; i++) { blur(inPixels, outPixels, width, height, radius); blur(outPixels, inPixels, height, width, radius); }// www.j a v a2 s . c o m blured.setPixels(inPixels, 0, width, 0, 0, width, height); return blured; } private static void blur(int[] in, int[] out, int width, int height, int radius) { int widthMinus1 = width - 1; int tableSize = 2 * radius + 1; int divide[] = new int[256 * tableSize]; for (int index = 0; index < 256 * tableSize; index++) { divide[index] = index / tableSize; } int inIndex = 0; for (int y = 0; y < height; y++) { int outIndex = y; int ta = 0, tr = 0, tg = 0, tb = 0; for (int i = -radius; i <= radius; i++) { int rgb = in[inIndex + clamp(i, 0, width - 1)]; ta += (rgb >> 24) & 0xff; tr += (rgb >> 16) & 0xff; tg += (rgb >> 8) & 0xff; tb += rgb & 0xff; } for (int x = 0; x < width; x++) { out[outIndex] = (divide[ta] << 24) | (divide[tr] << 16) | (divide[tg] << 8) | divide[tb]; int i1 = x + radius + 1; if (i1 > widthMinus1) i1 = widthMinus1; int i2 = x - radius; if (i2 < 0) i2 = 0; int rgb1 = in[inIndex + i1]; int rgb2 = in[inIndex + i2]; ta += ((rgb1 >> 24) & 0xff) - ((rgb2 >> 24) & 0xff); tr += ((rgb1 & 0xff0000) - (rgb2 & 0xff0000)) >> 16; tg += ((rgb1 & 0xff00) - (rgb2 & 0xff00)) >> 8; tb += (rgb1 & 0xff) - (rgb2 & 0xff); outIndex += height; } inIndex += width; } } private static int clamp(int x, int a, int b) { return (x < a) ? a : (x > b) ? b : x; } }