Resources res = this.getContext().getResources();
 img = BitmapFactory.decodeResource(res, R.drawable.aa);
 Matrix matrix = new Matrix();
 matrix.postRotate(180); /*翻轉180度*/
 int width = img.getWidth();
 int height = img.getHeight();
 img_a = Bitmap.createBitmap(img, 0, 0, width, height, matrix, true);

然后可以直接把img_a draw到畫布上，canvas.drawBitmap(img_a, 10, 10, p)；

Matrix 是一個處理翻轉、縮放等圖像效果的重要類，Matrix.postScale 可設置縮放比例，默認為1

**********************************************************************
android 實現(xiàn)圖片的旋轉

**********************************************************************

public class ex04_22 extends Activity{
 
private ImageView mImageView;
private Button btn1,btn2;
private TextView mTextView;
private AbsoluteLayout layout1;
private int ScaleTimes=1,ScaleAngle=1;
 @Override
 public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.main);
 mImageView=(ImageView)findViewById(R.id.myImageView);
 final Bitmap bmp=BitmapFactory.decodeResource(this.getResources(),R.drawable.ex04_22_1);
 final int widthOrig=bmp.getWidth();
 final int heightOrig=bmp.getHeight();
 mImageView.setImageBitmap(bmp);
 btn1=(Button)findViewById(R.id.myButton1);
 btn1.setOnClickListener(new OnClickListener(){
 public void onClick(View v){
 ScaleAngle--;
 if(ScaleAngle<-60){
 ScaleAngle=-60;
 }
 int newWidth=widthOrig*ScaleTimes;
 int newHeight=heightOrig*ScaleTimes;
 float scaleWidth=((float)newWidth)/widthOrig;
 float scaleHeight=((float)newHeight)/heightOrig;
 Matrix matrix=new Matrix();
 matrix.postScale(scaleWidth, scaleHeight);
 matrix.setRotate(5*ScaleAngle);
 Bitmap resizeBitmap=Bitmap.createBitmap(bmp, 0, 0, widthOrig, heightOrig, matrix, true);
 BitmapDrawable myNewBitmapDrawable=new BitmapDrawable(resizeBitmap);
 mImageView.setImageDrawable(myNewBitmapDrawable);
 }
 });
 btn2=(Button)findViewById(R.id.myButton2);
 btn2.setOnClickListener(new OnClickListener(){
 public void onClick(View v){
 ScaleAngle++;
 if(ScaleAngle>60){
 ScaleAngle=60;
 }
 int newWidth=widthOrig*ScaleTimes;
 int newHeight=heightOrig*ScaleTimes;
 float scaleWidth=((float)newWidth)/widthOrig;
 float scaleHeight=((float)newHeight)/heightOrig;
 Matrix matrix=new Matrix();
 matrix.postScale(scaleWidth, scaleHeight);
 matrix.setRotate(5*ScaleAngle);
 Bitmap resizeBitmap=Bitmap.createBitmap(bmp, 0, 0, widthOrig, heightOrig, matrix, true);
 BitmapDrawable myNewBitmapDrawable=new BitmapDrawable(resizeBitmap);
 mImageView.setImageDrawable(myNewBitmapDrawable);
 }
 });
 }

**********************************************************************

實現(xiàn)畫面淡入淡出效果可以用：setAlpha(alpha);
alpha從255，逐漸遞減!

**********************************************************************

如何實現(xiàn)屏幕的滾動效果，這里有兩個關鍵點，一個是實現(xiàn)OnGestureListener，以便在觸摸事件發(fā)生的時候，被回調。包括按下，滾動等等，按照API文檔，需要分兩步來實現(xiàn)檢測手勢行為。

1）創(chuàng)建GestureDetector實例

2) 在onTouchEvent()方法中調用GestureDetector的onTouchEvent()方法。

另一個關鍵點是自己實現(xiàn)一個簡單的View，來繪制圖片。

代碼如下所示。由于，我們不需要使用layout定義，所以不需要提供xml文件。
直接在程序里面setContentView()即可。

package com.j2medev;
 
import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.GestureDetector.OnGestureListener;
 
public class HorizontalScroll extends Activity implements OnGestureListener {
private static final int X_MAX = 800;
private static final int Y_MAX = 600;
private int scrollX = 0;
private int scrollY = 0;
 
MyView main;
Bitmap bmp;
Bitmap adapt;
Resources res;
Paint paint;
GestureDetector gestureScanner;
 
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
 
gestureScanner = new GestureDetector(this);
paint = new Paint();
 
res = getResources();
bmp = BitmapFactory.decodeResource(res, R.drawable.arc);
adapt = Bitmap.createBitmap(bmp);
 
main = new MyView(this);
setContentView(main, new ViewGroup.LayoutParams(800, 600));
}
 
@Override
public boolean onTouchEvent(MotionEvent me) {
return gestureScanner.onTouchEvent(me);
}
 
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
 float distanceY) {
main.handleScroll(distanceX, distanceY);
return true;
}
 
public boolean onDown(MotionEvent e) {
return true;
}
 
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
 float velocityY) {
return true;
}
 
public void onLongPress(MotionEvent e) {
}
 
public void onShowPress(MotionEvent e) {
}
 
public boolean onSingleTapUp(MotionEvent e) {
return true;
}
 
// //////////////////
// /////////////////
// ////////////////
 
class MyView extends View {
public MyView(Context context) {
 super(context);
}
 
@Override
protected void onDraw(Canvas canvas) {
 canvas.drawBitmap(adapt, -scrollX, -scrollY, paint);
}
 
public void handleScroll(float distX, float distY) {
 // X-Axis ////////////////////////////////
 
 if (distX > 6.0) {
 if (scrollX < 460) {
 scrollX += 15;
 }
 } else if (distX < -6.0) {
 if (scrollX >= 15) {
 scrollX -= 15;
 }
 }
 // //////////////////////////////////////////
 
 // Y-AXIS //////////////////////////////////
 if (distY > 6.0) {
 if (scrollY < 100) {
 scrollY += 15;
 }
 } else if (distY < -6.0) {
 if (scrollY >= 15) {
 scrollY -= 15;
 }
 }
 // //////////////////////////////////////////
 //
 // if ((scrollX <= 480) && (scrollY <= 120)) {
 // adapt = Bitmap.createBitmap(bmp, scrollX, scrollY, 320, 480);
 // invalidate();
 // }
 invalidate();
}
}
}

**********************************************************************

教你在谷歌Android平臺中處理圖片

**********************************************************************

操作圖像像素

現(xiàn)在你可以對單獨的像素進行處理了。通過使用android.graphics.Bitmap API中的getPixels，可以加載像素到一個整數(shù)數(shù)組中。

在本文例子中，你將按照一定規(guī)則對每一個像素實現(xiàn)著色。經(jīng)過這個處理后，所有的像素將被轉化為一個范圍在0到255的字節(jié)碼。

android.graphics.Bitmap API中的setPixels則用來加載這個整數(shù)數(shù)組到一個圖像中。

最后一步是通過ImageView變量mIV來更新屏幕。以下是實現(xiàn)這個染色過程的代碼片段。

private void TintThePicture(int deg) {
 int[] pix = new int[picw * pich];
 mBitmap.getPixels(pix, 0, picw, 0, 0, picw, pich);
 
 int RY, GY, BY, RYY, GYY, BYY, R, G, B, Y;
 double angle = (3.14159d * (double)deg) / 180.0d;
 int S = (int)(256.0d * Math.sin(angle));
 int C = (int)(256.0d * Math.cos(angle));
 
 for (int y = 0; y < pich; y++)
 for (int x = 0; x < picw; x++)
 {
 int index = y * picw + x;
 int r = (pix[index] >> 16) & 0xff;
 int g = (pix[index] >> 8) & 0xff;
 int b = pix[index] & 0xff;
 RY = ( 70 * r - 59 * g - 11 * b) / 100;
 GY = (-30 * r + 41 * g - 11 * b) / 100;
 BY = (-30 * r - 59 * g + 89 * b) / 100;
 Y = ( 30 * r + 59 * g + 11 * b) / 100;
 RYY = (S * BY + C * RY) / 256;
 BYY = (C * BY - S * RY) / 256;
 GYY = (-51 * RYY - 19 * BYY) / 100;
 R = Y + RYY;
 R = (R < 0) ? 0 : ((R > 255) ? 255 : R);
 G = Y + GYY;
 G = (G < 0) ? 0 : ((G > 255) ? 255 : G);
 B = Y + BYY;
 B = (B < 0) ? 0 : ((B > 255) ? 255 : B);
 pix[index] = 0xff000000 | (R << 16) | (G << 8) | B;
 }
 
 Bitmap bm = Bitmap.createBitmap(picw, pich, false);
 bm.setPixels(pix, 0, picw, 0, 0, picw, pich);
 
 // Put the updated bitmap into the main view
 mIV.setImageBitmap(bm);
 mIV.invalidate();
 
 mBitmap = bm;
 pix = null;
 }

**********************************************************************

android 圖片的放大和縮小

**********************************************************************

public class ex04_22 extends Activity{
private ImageView mImageView;
private Button btn1,btn2;
private TextView mTextView;
private AbsoluteLayout layout1;
private Bitmap bmp;
private int id=0;
private int displayWidth,displayHeight;
private float scaleWidth=1,scaleHeight=1;
private final static String filename="/data/data/ex04_22.lcs/ex04_22_2.png";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//取得屏幕分辨率
DisplayMetrics dm=new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
displayWidth=dm.widthPixels;
displayHeight=dm.heightPixels-80;
bmp=BitmapFactory.decodeResource(this.getResources(),R.drawable.ex04_22_1);
layout1=(AbsoluteLayout)findViewById(R.id.layout1);
mImageView=(ImageView)findViewById(R.id.myImageView);
btn1=(Button)findViewById(R.id.myButton1);
btn1.setOnClickListener(new OnClickListener(){
public void onClick(View v){
small();
}
});
btn2=(Button)findViewById(R.id.myButton2);
btn2.setOnClickListener(new OnClickListener(){
public void onClick(View v){
big();
}
});
}
private void small(){
//獲得Bitmap的高和寬
int bmpWidth=bmp.getWidth();
int bmpHeight=bmp.getHeight();
//設置縮小比例
double scale=0.8;
//計算出這次要縮小的比例
scaleWidth=(float)(scaleWidth*scale);
scaleHeight=(float)(scaleHeight*scale);
//產(chǎn)生resize后的Bitmap對象
Matrix matrix=new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
Bitmap resizeBmp=Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true);
if(id==0){
layout1.removeView(mImageView);
}
else{
layout1.removeView((ImageView)findViewById(id));
}
id++;
ImageView imageView=new ImageView(this);
imageView.setId(id);
imageView.setImageBitmap(resizeBmp);
layout1.addView(imageView);
setContentView(layout1);
btn2.setEnabled(true);
}
private void big(){
//獲得Bitmap的高和寬
int bmpWidth=bmp.getWidth();
int bmpHeight=bmp.getHeight();
//設置縮小比例
double scale=1.25;
//計算出這次要縮小的比例
scaleWidth=(float)(scaleWidth*scale);
scaleHeight=(float)(scaleHeight*scale);
//產(chǎn)生resize后的Bitmap對象
Matrix matrix=new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
Bitmap resizeBmp=Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true);
if(id==0){
layout1.removeView(mImageView);
}
else{
layout1.removeView((ImageView)findViewById(id));
}
id++;
ImageView imageView=new ImageView(this);
imageView.setId(id);
imageView.setImageBitmap(resizeBmp);
layout1.addView(imageView);
setContentView(layout1);
if(scaleWidth*scale*bmpWidth>displayWidth||scaleHeight*scale*scaleHeight>displayHeight){
btn2.setEnabled(false);
}
}
}

xml文件

<?xml version="1.0" encoding="utf-8"?>
 
<AbsoluteLayout
android:id="@+id/layout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
>
<ImageView
android:id="@+id/myImageView"
android:layout_width="200px"
 
android:layout_height="150px"
android:src="@drawable/ex04_22_1"
android:layout_x="0px"
android:layout_y="0px"
>
</ImageView>
<Button
android:id="@+id/myButton1"
 
android:layout_width="90px"
android:layout_height="60px"
android:text="縮小"
android:textSize="18sp"
android:layout_x="20px"
android:layout_y="372px"
 
>
</Button>
<Button
android:id="@+id/myButton2"
android:layout_width="90px"
android:layout_height="60px"
android:text="放大"
android:textSize="18sp"
 
android:layout_x="210px"
android:layout_y="372px"
>
</Button>
</AbsoluteLayout>

*********************************************************************

android 圖片透明度處理代碼

*********************************************************************

public static Bitmap setAlpha(Bitmap sourceImg, int number) {
 
　　int[] argb = new int[sourceImg.getWidth() * sourceImg.getHeight()];
 
　　sourceImg.getPixels(argb, 0, sourceImg.getWidth(), 0, 0,sourceImg.getWidth(), sourceImg.getHeight());// 獲得圖片的ARGB值
 
　　number = number * 255 / 100;
 
　　for (int i = 0; i < argb.length; i++) {
 
　　argb = (number << 24) | (argb & 0x00FFFFFF);// 修改最高2位的值
 
　　}
 
　　sourceImg = Bitmap.createBitmap(argb, sourceImg.getWidth(), sourceImg.getHeight(), Config.ARGB_8888);
 
　　return sourceImg;
 
}

以上就是涉及到了Android圖片處理的所有內容，包括android圖片反轉、android 圖片翻轉、android 圖片旋轉、實現(xiàn)畫面淡入淡出效果、android 圖片的放大和縮小以及教你在谷歌Android平臺中處理圖片。

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