Android 實現圖片的翻轉
android 實現圖片的翻轉
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
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android 實現圖片的旋轉
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=widthOrigScaleTimes; int newHeight=heightOrigScaleTimes; float scaleWidth=((float)newWidth)/widthOrig; float scaleHeight=((float)newHeight)/heightOrig; Matrix matrix=new Matrix(); matrix.postScale(scaleWidth, scaleHeight); matrix.setRotate(5ScaleAngle); 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=widthOrigScaleTimes; int newHeight=heightOrigScaleTimes; float scaleWidth=((float)newWidth)/widthOrig; float scaleHeight=((float)newHeight)/heightOrig; Matrix matrix=new Matrix(); matrix.postScale(scaleWidth, scaleHeight); matrix.setRotate(5ScaleAngle); Bitmap resizeBitmap=Bitmap.createBitmap(bmp, 0, 0, widthOrig, heightOrig, matrix, true); BitmapDrawable myNewBitmapDrawable=new BitmapDrawable(resizeBitmap); mImageView.setImageDrawable(myNewBitmapDrawable); } }); }</pre>
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實現畫面淡入淡出效果可以用 :setAlpha(alpha);
alpha從255,逐漸遞減!**********************************************************************
如何實現屏幕的滾動效果,這里有兩個關鍵點,一個是實現OnGestureListener,
以便在觸摸事件發生的時候,被回調。包括按下,滾動等等,按照API文檔,
需要分兩步來實現檢測手勢行為。
1)創建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(); } } }</pre>
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教你在谷歌Android平臺中處理圖片
操作圖像像素
現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數組中。在本文例子中,你將按照一定規則對每一
個像素實現著色。經過這個處理后,所有的像素將被轉化為一個范圍在0到255的字節碼。
android.graphics.Bitmap API中的setPixels則用來加載這個整數數組到一個圖像中。
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;
}</pre>
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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></pre>
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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;
}</pre>