Android高斯模糊、高斯平滑(Gaussian Blur)【1】

Android高斯模糊、高斯平滑(Gaussian Blur)，图形图像处理的一种效果，经过高斯模糊处理后的图片有一种“毛玻璃”的效果。

Android上的高斯模糊实现算法不少，现在结合一个流传甚广的算法(注意，此算法的性能有待进一步提高)，写一个高斯模糊的例子，实现“毛玻璃”的图像效果。

写一个布局：

android:layout_width="match_parent"

android:layout_height="match_parent" >

android:id="@+id/blurButton"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="left"

android:text="高斯模糊 力度:0" />

android:id="@+id/restButton"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="right"

android:text="重置" />

android:id="@+id/imageView"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:src="@drawable/pic" />

测试的主Activity MainActivity.java：

package zhangphil.blur;

import android.widget.Button;

import android.widget.ImageView;

import android.app.Activity;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.os.Bundle;

import android.view.View;

public class MainActivity extends Activity {

private int radius = 0;

private Button blurButton;

private ImageView image;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

image = (ImageView) findViewById(R.id.imageView);

blurButton = (Button) findViewById(R.id.blurButton);

blurButton.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

doMyBlur();

}

});

Button restButton = (Button) findViewById(R.id.restButton);

restButton.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

rest();

}

});

}

// 每次都加深力度10

private void doMyBlur() {

radius = radius + 10;

Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.pic);

Bitmap bmp = FastBlur.doBlur(bitmap, radius, false);

image.setImageBitmap(bmp);

blurButton.setText("高斯模糊 力度:" + radius);

}

// 重置为原始状态

private void rest() {

radius = 0;

image.setImageResource(R.drawable.pic);

blurButton.setText("高斯模糊 力度:" + radius);

}

}

核心的工具类FastBlur.java：

package zhangphil.blur;

import android.graphics.Bitmap;

import android.util.Log;

public class FastBlur {

public Bitmap fastblur(Bitmap sentBitmap, int radius) {

// Stack Blur v1.0 from

// http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html

//

// Java Author: Mario Klingemann

// http://incubator.quasimondo.com

// created Feburary 29, 2004

// Android port : Yahel Bouaziz

// http://www.kayenko.com

// ported april 5th, 2012

// This is a compromise between Gaussian Blur and Box blur

// It creates much better looking blurs than Box Blur, but is

// 7x faster than my Gaussian Blur implementation.

//

// I called it Stack Blur because this describes best how this

// filter works internally: it creates a kind of moving stack

// of colors whilst scanning through the image. Thereby it

// just has to add one new block of color to the right side

// of the stack and remove the leftmost color. The remaining

// colors on the topmost layer of the stack are either added on

// or reduced by one, depending on if they are on the right or

// on the left side of the stack.

//

// If you are using this algorithm in your code please add

// the following line:

//

// Stack Blur Algorithm by Mario Klingemann

Bitmap bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);

if (radius < 1) {

return (null);

}

int w = bitmap.getWidth();

int h = bitmap.getHeight();

int[] pix = new int[w * h];

Log.e("pix", w + " " + h + " " + pix.length);

bitmap.getPixels(pix, 0, w, 0, 0, w, h);

int wm = w - 1;

int hm = h - 1;

int wh = w * h;

int div = radius + radius + 1;

int r[] = new int[wh];

int g[] = new int[wh];

int b[] = new int[wh];

int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;

int vmin[] = new int[Math.max(w, h)];

int divsum = (div + 1) >> 1;

divsum *= divsum;

int dv[] = new int[256 * divsum];

for (i = 0; i < 256 * divsum; i++) {

dv[i] = (i / divsum);

}

yw = yi = 0;

int[][] stack = new int[div][3];

int stackpointer;

int stackstart;

int[] sir;

int rbs;

int r1 = radius + 1;

int routsum, goutsum, boutsum;

int rinsum, ginsum, binsum;

for (y = 0; y < h; y++) {

rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;

for (i = -radius; i <= radius; i++) {

p = pix[yi + Math.min(wm, Math.max(i, 0))];

sir = stack[i + radius];

sir[0] = (p & 0xff0000) >> 16;

sir[1] = (p & 0x00ff00) >> 8;

sir[2] = (p & 0x0000ff);

rbs = r1 - Math.abs(i);

rsum += sir[0] * rbs;

gsum += sir[1] * rbs;

bsum += sir[2] * rbs;

if (i > 0) {

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

} else {

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

}

}

stackpointer = radius;

for (x = 0; x < w; x++) {

r[yi] = dv[rsum];

g[yi] = dv[gsum];

b[yi] = dv[bsum];

rsum -= routsum;

gsum -= goutsum;

bsum -= boutsum;

stackstart = stackpointer - radius + div;

sir = stack[stackstart % div];

routsum -= sir[0];

goutsum -= sir[1];

boutsum -= sir[2];

if (y == 0) {

vmin[x] = Math.min(x + radius + 1, wm);

}

p = pix[yw + vmin[x]];

sir[0] = (p & 0xff0000) >> 16;

sir[1] = (p & 0x00ff00) >> 8;

sir[2] = (p & 0x0000ff);

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

rsum += rinsum;

gsum += ginsum;

bsum += binsum;

stackpointer = (stackpointer + 1) % div;

sir = stack[(stackpointer) % div];

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

rinsum -= sir[0];

ginsum -= sir[1];

binsum -= sir[2];

yi++;

}

yw += w;

}

for (x = 0; x < w; x++) {

rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;

yp = -radius * w;

for (i = -radius; i <= radius; i++) {

yi = Math.max(0, yp) + x;

sir = stack[i + radius];

sir[0] = r[yi];

sir[1] = g[yi];

sir[2] = b[yi];

rbs = r1 - Math.abs(i);

rsum += r[yi] * rbs;

gsum += g[yi] * rbs;

bsum += b[yi] * rbs;

if (i > 0) {

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

} else {

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

}

if (i < hm) {

yp += w;

}

}

yi = x;

stackpointer = radius;

for (y = 0; y < h; y++) {

// Preserve alpha channel: ( 0xff000000 & pix[yi] )

pix[yi] = ( 0xff000000 & pix[yi] ) | ( dv[rsum] << 16 ) | ( dv[gsum] << 8 ) | dv[bsum];

rsum -= routsum;

gsum -= goutsum;

bsum -= boutsum;

stackstart = stackpointer - radius + div;

sir = stack[stackstart % div];

routsum -= sir[0];

goutsum -= sir[1];

boutsum -= sir[2];

if (x == 0) {

vmin[y] = Math.min(y + r1, hm) * w;

}

p = x + vmin[y];

sir[0] = r[p];

sir[1] = g[p];

sir[2] = b[p];

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

rsum += rinsum;

gsum += ginsum;

bsum += binsum;

stackpointer = (stackpointer + 1) % div;

sir = stack[stackpointer];

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

rinsum -= sir[0];

ginsum -= sir[1];

binsum -= sir[2];

yi += w;

}

}

Log.e("pix", w + " " + h + " " + pix.length);

bitmap.setPixels(pix, 0, w, 0, 0, w, h);

return (bitmap);

}

public static Bitmap doBlur(Bitmap sentBitmap, int radius,

boolean canReuseInBitmap) {

// Stack Blur v1.0 from

// http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html

//

// Java Author: Mario Klingemann

// http://incubator.quasimondo.com

// created Feburary 29, 2004

// Android port : Yahel Bouaziz

// http://www.kayenko.com

// ported april 5th, 2012

// This is a compromise between Gaussian Blur and Box blur

// It creates much better looking blurs than Box Blur, but is

// 7x faster than my Gaussian Blur implementation.

//

// I called it Stack Blur because this describes best how this

// filter works internally: it creates a kind of moving stack

// of colors whilst scanning through the image. Thereby it

// just has to add one new block of color to the right side

// of the stack and remove the leftmost color. The remaining

// colors on the topmost layer of the stack are either added on

// or reduced by one, depending on if they are on the right or

// on the left side of the stack.

//

// If you are using this algorithm in your code please add

// the following line:

//

// Stack Blur Algorithm by Mario Klingemann

Bitmap bitmap;

if (canReuseInBitmap) {

bitmap = sentBitmap;

} else {

bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);

}

if (radius < 1) {

return (null);

}

int w = bitmap.getWidth();

int h = bitmap.getHeight();

int[] pix = new int[w * h];

bitmap.getPixels(pix, 0, w, 0, 0, w, h);

int wm = w - 1;

int hm = h - 1;

int wh = w * h;

int div = radius + radius + 1;

int r[] = new int[wh];

int g[] = new int[wh];

int b[] = new int[wh];

int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;

int vmin[] = new int[Math.max(w, h)];

int divsum = (div + 1) >> 1;

divsum *= divsum;

int dv[] = new int[256 * divsum];

for (i = 0; i < 256 * divsum; i++) {

dv[i] = (i / divsum);

}

yw = yi = 0;

int[][] stack = new int[div][3];

int stackpointer;

int stackstart;

int[] sir;

int rbs;

int r1 = radius + 1;

int routsum, goutsum, boutsum;

int rinsum, ginsum, binsum;

for (y = 0; y < h; y++) {

rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;

for (i = -radius; i <= radius; i++) {

p = pix[yi + Math.min(wm, Math.max(i, 0))];

sir = stack[i + radius];

sir[0] = (p & 0xff0000) >> 16;

sir[1] = (p & 0x00ff00) >> 8;

sir[2] = (p & 0x0000ff);

rbs = r1 - Math.abs(i);

rsum += sir[0] * rbs;

gsum += sir[1] * rbs;

bsum += sir[2] * rbs;

if (i > 0) {

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

} else {

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

}

}

stackpointer = radius;

for (x = 0; x < w; x++) {

r[yi] = dv[rsum];

g[yi] = dv[gsum];

b[yi] = dv[bsum];

rsum -= routsum;

gsum -= goutsum;

bsum -= boutsum;

stackstart = stackpointer - radius + div;

sir = stack[stackstart % div];

routsum -= sir[0];

goutsum -= sir[1];

boutsum -= sir[2];

if (y == 0) {

vmin[x] = Math.min(x + radius + 1, wm);

}

p = pix[yw + vmin[x]];

sir[0] = (p & 0xff0000) >> 16;

sir[1] = (p & 0x00ff00) >> 8;

sir[2] = (p & 0x0000ff);

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

rsum += rinsum;

gsum += ginsum;

bsum += binsum;

stackpointer = (stackpointer + 1) % div;

sir = stack[(stackpointer) % div];

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

rinsum -= sir[0];

ginsum -= sir[1];

binsum -= sir[2];

yi++;

}

yw += w;

}

for (x = 0; x < w; x++) {

rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;

yp = -radius * w;

for (i = -radius; i <= radius; i++) {

yi = Math.max(0, yp) + x;

sir = stack[i + radius];

sir[0] = r[yi];

sir[1] = g[yi];

sir[2] = b[yi];

rbs = r1 - Math.abs(i);

rsum += r[yi] * rbs;

gsum += g[yi] * rbs;

bsum += b[yi] * rbs;

if (i > 0) {

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

} else {

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

}

if (i < hm) {

yp += w;

}

}

yi = x;

stackpointer = radius;

for (y = 0; y < h; y++) {

// Preserve alpha channel: ( 0xff000000 & pix[yi] )

pix[yi] = (0xff000000 & pix[yi]) | (dv[rsum] << 16)

| (dv[gsum] << 8) | dv[bsum];

rsum -= routsum;

gsum -= goutsum;

bsum -= boutsum;

stackstart = stackpointer - radius + div;

sir = stack[stackstart % div];

routsum -= sir[0];

goutsum -= sir[1];

boutsum -= sir[2];

if (x == 0) {

vmin[y] = Math.min(y + r1, hm) * w;

}

p = x + vmin[y];

sir[0] = r[p];

sir[1] = g[p];

sir[2] = b[p];

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

rsum += rinsum;

gsum += ginsum;

bsum += binsum;

stackpointer = (stackpointer + 1) % div;

sir = stack[stackpointer];

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

rinsum -= sir[0];

ginsum -= sir[1];

binsum -= sir[2];

yi += w;

}

}

bitmap.setPixels(pix, 0, w, 0, 0, w, h);

return (bitmap);

}

}

处理前的原始图片pic.png：

处理后的效果(radius=20)：