android bitmap 处理

引用：http://www.open-open.com/lib/view/open1325749794953.html

android 实现图片的翻转

1 Resources res = this.getContext().getResources();
2         img = BitmapFactory.decodeResource(res, R.drawable.aa);
3         Matrix matrix = new Matrix();
4         matrix.postRotate(180);        /*翻转180度*/
5         int width = img.getWidth();
6         int height = img.getHeight();
7         img_a = Bitmap.createBitmap(img, 0, 0, width, height, matrix, true);

 

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

Matrix 是一个处理翻转、缩放等图像效果的重要类

Matrix.postScale 可设置缩放比例，默认为1

**********************************************************************
android 实现图片的旋转

01 public class ex04_22 extends Activity{
02
03 private ImageView mImageView;
04 private Button btn1,btn2;
05 private TextView mTextView;
06 private AbsoluteLayout layout1;
07 private int ScaleTimes=1,ScaleAngle=1;
08     @Override
09     public void onCreate(Bundle savedInstanceState) {
10         super.onCreate(savedInstanceState);
11         setContentView(R.layout.main);
12         mImageView=(ImageView)findViewById(R.id.myImageView);
13         final Bitmap bmp=BitmapFactory.decodeResource(this.getResources(),R.drawable.ex04_22_1);
14         final int widthOrig=bmp.getWidth();
15         final int heightOrig=bmp.getHeight();
16         mImageView.setImageBitmap(bmp);
17         btn1=(Button)findViewById(R.id.myButton1);
18         btn1.setOnClickListener(new OnClickListener(){
19          public void onClick(View v){
20           ScaleAngle--;
21           if(ScaleAngle<-60){
22            ScaleAngle=-60;
23           }
24           int newWidth=widthOrig*ScaleTimes;
25           int newHeight=heightOrig*ScaleTimes;
26           float scaleWidth=((float)newWidth)/widthOrig;
27           float scaleHeight=((float)newHeight)/heightOrig;
28           Matrix matrix=new Matrix();
29           matrix.postScale(scaleWidth, scaleHeight);
30           matrix.setRotate(5*ScaleAngle);
31           Bitmap resizeBitmap=Bitmap.createBitmap(bmp, 0, 0, widthOrig, heightOrig, matrix, true);
32           BitmapDrawable myNewBitmapDrawable=new BitmapDrawable(resizeBitmap);
33           mImageView.setImageDrawable(myNewBitmapDrawable);
34          }
35         });
36         btn2=(Button)findViewById(R.id.myButton2);
37         btn2.setOnClickListener(new OnClickListener(){
38          public void onClick(View v){
39           ScaleAngle++;
40           if(ScaleAngle>60){
41            ScaleAngle=60;
42           }
43           int newWidth=widthOrig*ScaleTimes;
44           int newHeight=heightOrig*ScaleTimes;
45           float scaleWidth=((float)newWidth)/widthOrig;
46           float scaleHeight=((float)newHeight)/heightOrig;
47           Matrix matrix=new Matrix();
48           matrix.postScale(scaleWidth, scaleHeight);
49           matrix.setRotate(5*ScaleAngle);
50           Bitmap resizeBitmap=Bitmap.createBitmap(bmp, 0, 0, widthOrig, heightOrig, matrix, true);
51           BitmapDrawable myNewBitmapDrawable=new BitmapDrawable(resizeBitmap);
52           mImageView.setImageDrawable(myNewBitmapDrawable);
53          }
54         });
55     }

 

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

实现画面淡入淡出效果可以用 ：setAlpha(alpha); 
alpha从255，逐渐递减!

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

如何实现屏幕的滚动效果，这里有两个关键点，一个是实现OnGestureListener，

以便在触摸事件发生的时候，被回调。包括按下，滚动等等，按照API文档，

需要分两步来实现检测手势行为。

1）创建GestureDetector实例

2) 在onTouchEvent()方法中调用GestureDetector的onTouchEvent()方法。

 

另一个关键点是自己实现一个简单的View，来绘制图片。

 

代码如下所示。由于，我们不需要使用layout定义，所以不需要提供xml文件。
直接在程序里面setContentView()即可。

001 package com.j2medev;
002
003 import android.app.Activity;
004 import android.content.Context;
005 import android.content.res.Resources;
006 import android.graphics.Bitmap;
007 import android.graphics.BitmapFactory;
008 import android.graphics.Canvas;
009 import android.graphics.Paint;
010 import android.os.Bundle;
011 import android.view.GestureDetector;
012 import android.view.MotionEvent;
013 import android.view.View;
014 import android.view.ViewGroup;
015 import android.view.GestureDetector.OnGestureListener;
016
017 public class HorizontalScroll extends Activity implements OnGestureListener {
018 private static final int X_MAX = 800;
019 private static final int Y_MAX = 600;
020 private int scrollX = 0;
021 private int scrollY = 0;
022
023 MyView main;
024 Bitmap bmp;
025 Bitmap adapt;
026 Resources res;
027 Paint paint;
028 GestureDetector gestureScanner;
029
030 @Override
031 public void onCreate(Bundle savedInstanceState) {
032 super.onCreate(savedInstanceState);
033
034 gestureScanner = new GestureDetector(this);
035 paint = new Paint();
036
037 res = getResources();
038 bmp = BitmapFactory.decodeResource(res, R.drawable.arc);
039 adapt = Bitmap.createBitmap(bmp);
040
041 main = new MyView(this);
042 setContentView(main, new ViewGroup.LayoutParams(800, 600));
043 }
044
045 @Override
046 public boolean onTouchEvent(MotionEvent me) {
047 return gestureScanner.onTouchEvent(me);
048 }
049
050 public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
051    float distanceY) {
052 main.handleScroll(distanceX, distanceY);
053 return true;
054 }
055
056 public boolean onDown(MotionEvent e) {
057 return true;
058 }
059
060 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
061    float velocityY) {
062 return true;
063 }
064
065 public void onLongPress(MotionEvent e) {
066 }
067
068 public void onShowPress(MotionEvent e) {
069 }
070
071 public boolean onSingleTapUp(MotionEvent e) {
072 return true;
073 }
074
075 // //////////////////
076 // /////////////////
077 // ////////////////
078
079 class MyView extends View {
080 public MyView(Context context) {
081    super(context);
082 }
083
084 @Override
085 protected void onDraw(Canvas canvas) {
086    canvas.drawBitmap(adapt, -scrollX, -scrollY, paint);
087 }
088
089 public void handleScroll(float distX, float distY) {
090    // X-Axis ////////////////////////////////
091
092    if (distX > 6.0) {
093     if (scrollX < 460) {
094      scrollX += 15;
095     }
096    } else if (distX < -6.0) {
097     if (scrollX >= 15) {
098      scrollX -= 15;
099     }
100    }
101    // //////////////////////////////////////////
102
103    // Y-AXIS //////////////////////////////////
104    if (distY > 6.0) {
105     if (scrollY < 100) {
106      scrollY += 15;
107     }
108    } else if (distY < -6.0) {
109     if (scrollY >= 15) {
110      scrollY -= 15;
111     }
112    }
113    // //////////////////////////////////////////
114    //
115    // if ((scrollX <= 480) && (scrollY <= 120)) {
116    // adapt = Bitmap.createBitmap(bmp, scrollX, scrollY, 320, 480);
117    // invalidate();
118    // }
119    invalidate();
120 }
121 }
122 }

 

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

教你在谷歌Android平台中处理图片

操作图像像素

现在你可以对单独的像素进行处理了。通过使用android.graphics.Bitmap API中的

getPixels，可以加载像素到一个整数数组中。在本文例子中，你将按照一定规则对每一

个像素实现着色。经过这个处理后，所有的像素将被转化为一个范围在0到255的字节码。

android.graphics.Bitmap API中的setPixels则用来加载这个整数数组到一个图像中。

最后一步是通过ImageView变量mIV来更新屏幕。以下是实现这个染色过程的代码片段。

01 private void TintThePicture(int deg) {
02    int[] pix = new int[picw * pich];
03    mBitmap.getPixels(pix, 0, picw, 0, 0, picw, pich);
04
05    int RY, GY, BY, RYY, GYY, BYY, R, G, B, Y;
06    double angle = (3.14159d * (double)deg) / 180.0d;
07    int S = (int)(256.0d * Math.sin(angle));
08    int C = (int)(256.0d * Math.cos(angle));
09
10     for (int y = 0; y < pich; y++)
11     for (int x = 0; x < picw; x++)
12        {
13        int index = y * picw + x;
14        int r = (pix[index] >> 16) & 0xff;
15        int g = (pix[index] >> 8) & 0xff;
16        int b = pix[index] & 0xff;
17        RY = ( 70 * r - 59 * g - 11 * b) / 100;
18        GY = (-30 * r + 41 * g - 11 * b) / 100;
19        BY = (-30 * r - 59 * g + 89 * b) / 100;
20        Y = ( 30 * r + 59 * g + 11 * b) / 100;
21        RYY = (S * BY + C * RY) / 256;
22        BYY = (C * BY - S * RY) / 256;
23        GYY = (-51 * RYY - 19 * BYY) / 100;
24        R = Y + RYY;
25        R = (R < 0) ? 0 : ((R > 255) ? 255 : R);
26        G = Y + GYY;
27        G = (G < 0) ? 0 : ((G > 255) ? 255 : G);
28        B = Y + BYY;
29        B = (B < 0) ? 0 : ((B > 255) ? 255 : B);
30        pix[index] = 0xff000000 | (R << 16) | (G << 8) | B;
31        }
32
33     Bitmap bm = Bitmap.createBitmap(picw, pich, false);
34     bm.setPixels(pix, 0, picw, 0, 0, picw, pich);
35
36     // Put the updated bitmap into the main view
37     mIV.setImageBitmap(bm);
38     mIV.invalidate();
39
40     mBitmap = bm;
41     pix = null;
42  }

 

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

android 图片的放大和缩小

01 public class ex04_22 extends Activity{
02 private ImageView mImageView;
03 private Button btn1,btn2;
04 private TextView mTextView;
05 private AbsoluteLayout layout1;
06 private Bitmap bmp;
07 private int id=0;
08 private int displayWidth,displayHeight;
09 private float scaleWidth=1,scaleHeight=1;
10 private final static String filename="/data/data/ex04_22.lcs/ex04_22_2.png";
11 @Override
12 public void onCreate(Bundle savedInstanceState) {
13 super.onCreate(savedInstanceState);
14 setContentView(R.layout.main);
15 //取得屏幕分辨率
16 DisplayMetrics dm=new DisplayMetrics();
17 getWindowManager().getDefaultDisplay().getMetrics(dm);
18 displayWidth=dm.widthPixels;
19 displayHeight=dm.heightPixels-80;
20 bmp=BitmapFactory.decodeResource(this.getResources(),R.drawable.ex04_22_1);
21 layout1=(AbsoluteLayout)findViewById(R.id.layout1);
22 mImageView=(ImageView)findViewById(R.id.myImageView);
23 btn1=(Button)findViewById(R.id.myButton1);
24 btn1.setOnClickListener(new OnClickListener(){
25 public void onClick(View v){
26 small();
27 }
28 });
29 btn2=(Button)findViewById(R.id.myButton2);
30 btn2.setOnClickListener(new OnClickListener(){
31 public void onClick(View v){
32 big();
33 }
34 });
35 }
36 private void small(){
37 //获得Bitmap的高和宽
38 int bmpWidth=bmp.getWidth();
39 int bmpHeight=bmp.getHeight();
40 //设置缩小比例
41 double scale=0.8;
42 //计算出这次要缩小的比例
43 scaleWidth=(float)(scaleWidth*scale);
44 scaleHeight=(float)(scaleHeight*scale);
45 //产生resize后的Bitmap对象
46 Matrix matrix=new Matrix();
47 matrix.postScale(scaleWidth, scaleHeight);
48 Bitmap resizeBmp=Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true);
49 if(id==0){
50 layout1.removeView(mImageView);
51 }
52 else{
53 layout1.removeView((ImageView)findViewById(id));
54 }
55 id++;
56 ImageView imageView=new ImageView(this);
57 imageView.setId(id);
58 imageView.setImageBitmap(resizeBmp);
59 layout1.addView(imageView);
60 setContentView(layout1);
61 btn2.setEnabled(true);
62 }
63 private void big(){
64 //获得Bitmap的高和宽
65 int bmpWidth=bmp.getWidth();
66 int bmpHeight=bmp.getHeight();
67 //设置缩小比例
68 double scale=1.25;
69 //计算出这次要缩小的比例
70 scaleWidth=(float)(scaleWidth*scale);
71 scaleHeight=(float)(scaleHeight*scale);
72 //产生resize后的Bitmap对象
73 Matrix matrix=new Matrix();
74 matrix.postScale(scaleWidth, scaleHeight);
75 Bitmap resizeBmp=Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true);
76 if(id==0){
77 layout1.removeView(mImageView);
78 }
79 else{
80 layout1.removeView((ImageView)findViewById(id));
81 }
82 id++;
83 ImageView imageView=new ImageView(this);
84 imageView.setId(id);
85 imageView.setImageBitmap(resizeBmp);
86 layout1.addView(imageView);
87 setContentView(layout1);
88 if(scaleWidth*scale*bmpWidth>displayWidth||scaleHeight*scale*scaleHeight>displayHeight){
89 btn2.setEnabled(false);
90 }
91 }
92 }

 

xml文件

01 <?xml version="1.0" encoding="utf-8"?>
02
03 <AbsoluteLayout
04 android:id="@+id/layout1"
05 android:layout_width="fill_parent"
06 android:layout_height="fill_parent"
07 xmlns:android="http://schemas.android.com/apk/res/android"
08 >
09 <ImageView
10 android:id="@+id/myImageView"
11 android:layout_width="200px"
12
13 android:layout_height="150px"
14 android:src="@drawable/ex04_22_1"
15 android:layout_x="0px"
16 android:layout_y="0px"
17 >
18 </ImageView>
19 <Button
20 android:id="@+id/myButton1"
21
22 android:layout_width="90px"
23 android:layout_height="60px"
24 android:text="缩小"
25 android:textSize="18sp"
26 android:layout_x="20px"
27 android:layout_y="372px"
28
29 >
30 </Button>
31 <Button
32 android:id="@+id/myButton2"
33 android:layout_width="90px"
34 android:layout_height="60px"
35 android:text="放大"
36 android:textSize="18sp"
37
38 android:layout_x="210px"
39 android:layout_y="372px"
40 >
41 </Button>
42 </AbsoluteLayout>

 

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

android 图片透明度处理代码

01 public static Bitmap setAlpha(Bitmap sourceImg, int number) {
02
03 　　int[] argb = new int[sourceImg.getWidth() * sourceImg.getHeight()];
04
05 　　sourceImg.getPixels(argb, 0, sourceImg.getWidth(), 0, 0,sourceImg.getWidth(), sourceImg.getHeight());// 获得图片的ARGB值
06
07 　　number = number * 255 / 100;
08
09 　　for (int i = 0; i < argb.length; i++) {
10
11 　　argb = (number << 24) | (argb & 0x00FFFFFF);// 修改最高2位的值
12
13 　　}
14
15 　　sourceImg = Bitmap.createBitmap(argb, sourceImg.getWidth(), sourceImg.getHeight(), Config.ARGB_8888);
16
17 　　return sourceImg;
18
19 }