Android实现图片反转、翻转、旋转、放大和缩小

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android 实现图片的翻转

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Resources res = this.getContext().getResources();
img = BitmapFactory.decodeResource(res, R.drawable.aa);
Matrix matrix = new Matrix();
matrix.postRotate(180); /*翻转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

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android 实现图片的旋转

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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);
}
});
}

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

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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。

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();
}
}
}

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教你在谷歌Android平台中处理图片

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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。

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;
}

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android 图片的放大和缩小

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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(){
//获得Bitmap的高和宽
int bmpWidth=bmp.getWidth();
int bmpHeight=bmp.getHeight();
//设置缩小比例
double scale=0.8;
//计算出这次要缩小的比例
scaleWidth=(float)(scaleWidth*scale);
scaleHeight=(float)(scaleHeight*scale);
//产生resize后的Bitmap对象
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(){
//获得Bitmap的高和宽
int bmpWidth=bmp.getWidth();
int bmpHeight=bmp.getHeight();
//设置缩小比例
double scale=1.25;
//计算出这次要缩小的比例
scaleWidth=(float)(scaleWidth*scale);
scaleHeight=(float)(scaleHeight*scale);
//产生resize后的Bitmap对象
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="缩小"
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>

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android 图片透明度处理代码

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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());// 获得图片的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;

}