getPixels

package com.example.tt;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;
import android.widget.ScrollView;
import android.widget.Scroller;

public class MainActivity extends  Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);

setContentView(new MyView(getApplicationContext()));
}

class MyView extends View{

public MyView(Context context) {
super(context);
}

@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
canvas.drawColor(Color.GRAY);
Bitmap bitmapSrc=BitmapFactory.decodeResource(getResources(), R.drawable.img);

int bmpSrcW=bitmapSrc.getWidth();
int bmpSrcH=bitmapSrc.getHeight();
Paint paint=new Paint();
paint.setTextSize(50);
paint.setColor(Color.RED);
canvas.drawText("宽："+bmpSrcW+" 高："+bmpSrcH, 10, 60,paint );
canvas.translate(0, 60);

canvas.drawBitmap(bitmapSrc, 0, 0, null);
/*
* int[] pixels=new int [bmpSrcH*bmpSrcW];
* bitmapSrc.getPixels(pixels, 0, bmpSrcW, 0, 0, bmpSrcW, bmpSrcH);
*
* 把图片中的各个像素的值放到了pixels数组中，bitmap中像素按从左到右，从上到下次序依次放到pixels中，
* 第三个参数通常使用图片宽度即可，第二个参数是从pixels数组中那个位置开始存放像素值。
* 第4、5个参数是bitmap中像素坐标
* 最后两个是要获取的图片的宽高
*
*/

Bitmap newBmp = change1(bitmapSrc, bmpSrcW, bmpSrcH);
canvas.drawBitmap(newBmp, bmpSrcW+10,0 , null);

newBmp = change2(bitmapSrc, bmpSrcW, bmpSrcH);
canvas.drawBitmap(newBmp, 0, bmpSrcH+10 , null);

newBmp = change3(bitmapSrc, bmpSrcW, bmpSrcH);
canvas.drawBitmap(newBmp,  bmpSrcW+10, bmpSrcH+10 , null);

newBmp = change4(bitmapSrc, bmpSrcW, bmpSrcH);
canvas.drawBitmap(newBmp,0 , ( bmpSrcH+10)*2 , null);

newBmp = change5(bitmapSrc, bmpSrcW, bmpSrcH);
canvas.drawBitmap(newBmp,bmpSrcW+10 , ( bmpSrcH+10)*2 , null);

newBmp = change6(bitmapSrc, bmpSrcW, bmpSrcH);
canvas.drawBitmap(newBmp,0 , ( bmpSrcH+10)*3 , null);

newBmp = change7(bitmapSrc, bmpSrcW, bmpSrcH);
canvas.drawBitmap(newBmp,bmpSrcW+10 , ( bmpSrcH+10)*3 , null);

}

/**
* 对角调换
* @param bitmapSrc
* @param bmpSrcW
* @param bmpSrcH
* @return
*/
private Bitmap change1(Bitmap bitmapSrc, int bmpSrcW, int bmpSrcH) {
int[] pixels=new int [bmpSrcH*bmpSrcW];

bitmapSrc.getPixels(pixels, 0, bmpSrcW, 0, 0, bmpSrcW, bmpSrcH);

for (int i = 0; i < pixels.length/2; i++) {
int tmp=pixels[i];

pixels[i]=pixels[pixels.length-1-i];

pixels[pixels.length-1-i]=tmp;
}

Bitmap newBmp=Bitmap.createBitmap(pixels, 0, bmpSrcW, bmpSrcW, bmpSrcH, Config.ARGB_8888);
return newBmp;
}

/**
* 上下对调
* @param bitmapSrc
* @param bmpSrcW
* @param bmpSrcH
* @return
*/
private Bitmap change2(Bitmap bitmapSrc, int bmpSrcW, int bmpSrcH) {
int[] pixels=new int [bmpSrcH*bmpSrcW];

bitmapSrc.getPixels(pixels, 0, bmpSrcW, 0, 0, bmpSrcW, bmpSrcH);

for (int i = 0; i < bmpSrcH/2; i++) {

for (int j = 0; j < bmpSrcW; j++) {
int tmp=pixels[i*bmpSrcW+j];

pixels[i*bmpSrcW+j]=pixels[ ( bmpSrcH-1-i) * bmpSrcW+j    ];

pixels[ ( bmpSrcH-1-i) * bmpSrcW+j    ]=tmp;
}

}

Bitmap newBmp=Bitmap.createBitmap(pixels, 0, bmpSrcW, bmpSrcW, bmpSrcH, Config.ARGB_8888);
return newBmp;
}

/**
* 左右对调
* @param bitmapSrc
* @param bmpSrcW
* @param bmpSrcH
* @return
*/
private Bitmap change3(Bitmap bitmapSrc, int bmpSrcW, int bmpSrcH) {
int[] pixels=new int [bmpSrcH*bmpSrcW];

bitmapSrc.getPixels(pixels, 0, bmpSrcW, 0, 0, bmpSrcW, bmpSrcH);

for (int i = 0; i < bmpSrcW/2; i++) {

for (int j = 0; j < bmpSrcH; j++) {
int tmp=pixels[j*bmpSrcW+i];

pixels[j*bmpSrcW+i]=pixels[ (j+1)*bmpSrcW-i-1   ];

pixels[  (j+1)*bmpSrcW-i -1  ]=tmp;
}

}

Bitmap newBmp=Bitmap.createBitmap(pixels, 0, bmpSrcW, bmpSrcW, bmpSrcH, Config.ARGB_8888);
return newBmp;
}
/**
* 截取一块
* @param bitmapSrc
* @param bmpSrcW
* @param bmpSrcH
* @return
*/
private Bitmap change4(Bitmap bitmapSrc, int bmpSrcW, int bmpSrcH) {
int[] pixels=new int [bmpSrcH*bmpSrcW];

for (int i = 0; i < pixels.length; i++) {
pixels[i]=Color.BLUE;
}

bitmapSrc.getPixels(pixels, bmpSrcW*60+80, bmpSrcW, 80, 60,200 ,160 );

Bitmap newBmp=Bitmap.createBitmap(pixels, 0, bmpSrcW, bmpSrcW, bmpSrcH, Config.ARGB_8888);
return newBmp;
}
/**
* 截取一块并置于左上角
* @param bitmapSrc
* @param bmpSrcW
* @param bmpSrcH
* @return
*/
private Bitmap change5(Bitmap bitmapSrc, int bmpSrcW, int bmpSrcH) {
int[] pixels=new int [bmpSrcH*bmpSrcW];

for (int i = 0; i < pixels.length; i++) {
pixels[i]=Color.BLUE;
}

bitmapSrc.getPixels(pixels,0, bmpSrcW, 80, 60,200 ,160 );

Bitmap newBmp=Bitmap.createBitmap(pixels, 0, bmpSrcW, bmpSrcW, bmpSrcH, Config.ARGB_8888);
return newBmp;
}
/**
* 默认背景透明
* @param bitmapSrc
* @param bmpSrcW
* @param bmpSrcH
* @return
*/
private Bitmap change6(Bitmap bitmapSrc, int bmpSrcW, int bmpSrcH) {
int[] pixels=new int [bmpSrcH*bmpSrcW];

bitmapSrc.getPixels(pixels,20, bmpSrcW, 80, 60,200 ,160 );

Bitmap newBmp=Bitmap.createBitmap(pixels, 0, bmpSrcW, bmpSrcW, bmpSrcH, Config.ARGB_8888);
return newBmp;
}

/**
* 泛红效果
* @param bitmapSrc
* @param bmpSrcW
* @param bmpSrcH
* @return
*/
private Bitmap change7(Bitmap bitmapSrc, int bmpSrcW, int bmpSrcH) {
int[] pixels=new int [bmpSrcH*bmpSrcW];

bitmapSrc.getPixels(pixels,0, bmpSrcW, 0, 0,bmpSrcW ,bmpSrcH );

for (int i = 0; i < pixels.length; i++) {
int argb=pixels[i];
//一个像素包含alpha，red,green,blue，分别占8位，组成一个32位的int值
//argb占32位，即java中int类型的大小，左起前8位代表alpha（透明度）,接着8位是red的值，然后8位是green，最后8位是blue，
//8位二进制的最大值是2^8-1，即16进制0xff，10进制255
//  0xff  前24位是0，后8位是1，即   00000000 00000000 00000000 11111111
//argb>>16后，左起前16位是0，接着8位是alpha，最后8位是red值，与0xff做 & 运算，（按位与，对应位同为1才是1，否则是0）
//所以运算后前24位是0，后8位原来是1则还是1，原来是0则是0，所以后8位的值不变，前24位变为了0，所以就取出了red值，
//green,blue值的取法类似

//可以使用Color.red(argb);获取该像素中的red值
int r=  ( argb>> 16 )   &   0xff;

int g=  ( argb>> 8 )   &   0xff;

int b=    argb   &   0xff;

r=(int) (r*1.5);
if (r>0xff) {
r=0xff;
}
//
//				g=(int) (g*1.2);
//				if (g>0xff) {
//					g=0xff;
//				}
//
//				b=(int) (b*1.2);
//				if (b>0xff) {
//					b=0xff;
//				}

//0xff<<24，把透明度置为完全不透明（透明度表示后面的rgb颜色的加深程度，所以透明度值越大，颜色越深，透明度为0时表示完全透明）
//0xff<<24后右起24位位0，左起8位为alpha。
//r<<16后左起8位为0，右边16位为0,其他位为red值
//g<<8后左起16位为0，右起8位为0，其他位为green值
//使用 | 运算后就把argb拼接了起来得到了32位的值，即一个像素的值

//可以使用Color.rgb();得到像素值
argb= (0xff<<24)  | (r<<16)  | (g<<8) | b;

pixels[i]=argb;
}

Bitmap newBmp=Bitmap.createBitmap(pixels, 0, bmpSrcW, bmpSrcW, bmpSrcH, Config.ARGB_8888);
return newBmp;
}
}

}