Android 图片处理方法

//压缩图片大小
    public static Bitmap compressImage(Bitmap image) {

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        image.compress(Bitmap.CompressFormat.JPEG, 100, baos);//质量压缩方法，这里100表示不压缩，把压缩后的数据存放到baos中
        int options = 100;
        while ( baos.toByteArray().length / 1024>100) {    //循环判断如果压缩后图片是否大于100kb,大于继续压缩        
            baos.reset();//重置baos即清空baos
            image.compress(Bitmap.CompressFormat.JPEG, options, baos);//这里压缩options%，把压缩后的数据存放到baos中
            options -= 10;//每次都减少10
        }
        ByteArrayInputStream isBm = new ByteArrayInputStream(baos.toByteArray());//把压缩后的数据baos存放到ByteArrayInputStream中
        Bitmap bitmap = BitmapFactory.decodeStream(isBm, null, null);//把ByteArrayInputStream数据生成图片
        return bitmap;
    }

/** 
     * 将彩色图转换为灰度图 
     * @param img 位图 
     * @return  返回转换好的位图 
     */  
    public Bitmap convertGreyImg(Bitmap img) {  
        int width = img.getWidth();         //获取位图的宽  
        int height = img.getHeight();       //获取位图的高  
          
        int []pixels = new int[width * height]; //通过位图的大小创建像素点数组  
          
        img.getPixels(pixels, 0, width, 0, 0, width, height);  
        int alpha = 0xFF << 24;   
        for(int i = 0; i < height; i++)  {  
            for(int j = 0; j < width; j++) {  
                int grey = pixels[width * i + j];  
                  
                int red = ((grey  & 0x00FF0000 ) >> 16);  
                int green = ((grey & 0x0000FF00) >> 8);  
                int blue = (grey & 0x000000FF);  
                  
                grey = (int)((float) red * 0.3 + (float)green * 0.59 + (float)blue * 0.11);  
                grey = alpha | (grey << 16) | (grey << 8) | grey;  
                pixels[width * i + j] = grey;  
            }  
        }  
        Bitmap result = Bitmap.createBitmap(width, height, Config.RGB_565);  
        result.setPixels(pixels, 0, width, 0, 0, width, height);  
        return result;  
    }  

将一个图片切割成多个图片
有种场景，我们想将一个图片切割成多个图片。比如我们在开发一个拼图的游戏，就首先要对图片进行切割。
以下是封装好的两个类，可以实现图片的切割。仅供参考和学习。
一个是ImagePiece类，此类保存了一个Bitmap对象和一个标识图片的顺序索引的int变量。

import android.graphics.Bitmap; 
public class ImagePiece {   
    public int index = 0;        
    public Bitmap bitmap = null;  
}

一个是ImageSplitter类，有一个静态方法split，传入的参数是要切割的Bitmap对象，和横向和竖向的切割片数。比如传入的是3、3，则横竖向都切割成3片，最终会将整个图片切割成3X3=9片。

import java.util.ArrayList;  
import java.util.List;  
  
import android.graphics.Bitmap;  
  
public class ImageSplitter {  
  
    public static List<ImagePiece> split(Bitmap bitmap, int xPiece, int yPiece) {  
  
        List<ImagePiece> pieces = new ArrayList<ImagePiece>(xPiece * yPiece);  
        int width = bitmap.getWidth();  
        int height = bitmap.getHeight();  
        int pieceWidth = width / 3;  
        int pieceHeight = height / 3;  
        for (int i = 0; i < yPiece; i++) {  
            for (int j = 0; j < xPiece; j++) {  
                ImagePiece piece = new ImagePiece();  
                piece.index = j + i * xPiece;  
                int xValue = j * pieceWidth;  
                int yValue = i * pieceHeight;  
                piece.bitmap = Bitmap.createBitmap(bitmap, xValue, yValue,  
                        pieceWidth, pieceHeight);  
                pieces.add(piece);  
            }  
        }  
  
        return pieces;  
    }  
  
}

1、图标加灰色过滤；

2、android的图片资源默认是静态的，单实例；如果两个IM好友的头像一样，最简单的都是用的软件自带头像，有一个在线，一个离线，直接改变头像的灰度，则两个用户的头像都会变灰或者在线，答案是：Drawable.mutate()。

Drawable mDrawable = context.getResources().getDrawable(R.drawable.face_icon);  
//Make this drawable mutable.  
//A mutable drawable is guaranteed to not share its state with any other drawable.  
mDrawable.mutate();  
ColorMatrix cm = new ColorMatrix();  
cm.setSaturation(0);  
ColorMatrixColorFilter cf = new ColorMatrixColorFilter(cm);  
mDrawable.setColorFilter(cf);

生成缩略图，抠自android launcher源码：

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.launcher;

import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.PaintDrawable;
import android.graphics.Bitmap;
import android.graphics.PixelFormat;
import android.graphics.Canvas;
import android.graphics.PaintFlagsDrawFilter;
import android.graphics.Paint;
import android.graphics.Rect;
import android.content.res.Resources;
import android.content.Context;

/**
 * Various utilities shared amongst the Launcher's classes.
 */
final class Utilities {
    private static int sIconWidth = -1;
    private static int sIconHeight = -1;

    private static final Paint sPaint = new Paint();
    private static final Rect sBounds = new Rect();
    private static final Rect sOldBounds = new Rect();
    private static Canvas sCanvas = new Canvas();

    static {
        sCanvas.setDrawFilter(new PaintFlagsDrawFilter(Paint.DITHER_FLAG,
                Paint.FILTER_BITMAP_FLAG));
    }

    /**
     * Returns a Drawable representing the thumbnail of the specified Drawable.
     * The size of the thumbnail is defined by the dimension
     * android.R.dimen.launcher_application_icon_size.
     *
     * This method is not thread-safe and should be invoked on the UI thread only.
     *
     * @param icon The icon to get a thumbnail of.
     * @param context The application's context.
     *
     * @return A thumbnail for the specified icon or the icon itself if the
     *         thumbnail could not be created. 
     */
    static Drawable createIconThumbnail(Drawable icon, Context context) {
        if (sIconWidth == -1) {
            final Resources resources = context.getResources();
            sIconWidth = sIconHeight = (int) resources.getDimension(android.R.dimen.app_icon_size);
        }

        int width = sIconWidth;
        int height = sIconHeight;

        float scale = 1.0f;
        if (icon instanceof PaintDrawable) {
            PaintDrawable painter = (PaintDrawable) icon;
            painter.setIntrinsicWidth(width);
            painter.setIntrinsicHeight(height);
        } else if (icon instanceof BitmapDrawable) {
            // Ensure the bitmap has a density.
            BitmapDrawable bitmapDrawable = (BitmapDrawable) icon;
            Bitmap bitmap = bitmapDrawable.getBitmap();
            if (bitmap.getDensity() == Bitmap.DENSITY_NONE) {
                bitmapDrawable.setTargetDensity(context.getResources().getDisplayMetrics());
            }
        }
        int iconWidth = icon.getIntrinsicWidth();
        int iconHeight = icon.getIntrinsicHeight();

        if (width > 0 && height > 0) {
            if (width < iconWidth || height < iconHeight || scale != 1.0f) {
                final float ratio = (float) iconWidth / iconHeight;

                if (iconWidth > iconHeight) {
                    height = (int) (width / ratio);
                } else if (iconHeight > iconWidth) {
                    width = (int) (height * ratio);
                }

                final Bitmap.Config c = icon.getOpacity() != PixelFormat.OPAQUE ?
                            Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565;
                final Bitmap thumb = Bitmap.createBitmap(sIconWidth, sIconHeight, c);
                final Canvas canvas = sCanvas;
                canvas.setBitmap(thumb);
                // Copy the old bounds to restore them later
                // If we were to do oldBounds = icon.getBounds(),
                // the call to setBounds() that follows would
                // change the same instance and we would lose the
                // old bounds
                sOldBounds.set(icon.getBounds());
                final int x = (sIconWidth - width) / 2;
                final int y = (sIconHeight - height) / 2;
                icon.setBounds(x, y, x + width, y + height);
                icon.draw(canvas);
                icon.setBounds(sOldBounds);
                icon = new FastBitmapDrawable(thumb);
            } else if (iconWidth < width && iconHeight < height) {
                final Bitmap.Config c = Bitmap.Config.ARGB_8888;
                final Bitmap thumb = Bitmap.createBitmap(sIconWidth, sIconHeight, c);
                final Canvas canvas = sCanvas;
                canvas.setBitmap(thumb);
                sOldBounds.set(icon.getBounds());
                final int x = (width - iconWidth) / 2;
                final int y = (height - iconHeight) / 2;
                icon.setBounds(x, y, x + iconWidth, y + iconHeight);
                icon.draw(canvas);
                icon.setBounds(sOldBounds);
                icon = new FastBitmapDrawable(thumb);
            }
        }

        return icon;
    }

    /**
     * Returns a Bitmap representing the thumbnail of the specified Bitmap.
     * The size of the thumbnail is defined by the dimension
     * android.R.dimen.launcher_application_icon_size.
     *
     * This method is not thread-safe and should be invoked on the UI thread only.
     *
     * @param bitmap The bitmap to get a thumbnail of.
     * @param context The application's context.
     *
     * @return A thumbnail for the specified bitmap or the bitmap itself if the
     *         thumbnail could not be created.
     */
    static Bitmap createBitmapThumbnail(Bitmap bitmap, Context context) {
        if (sIconWidth == -1) {
            final Resources resources = context.getResources();
            sIconWidth = sIconHeight = (int) resources.getDimension(
                    android.R.dimen.app_icon_size);
        }

        int width = sIconWidth;
        int height = sIconHeight;

        final int bitmapWidth = bitmap.getWidth();
        final int bitmapHeight = bitmap.getHeight();

        if (width > 0 && height > 0) {
            if (width < bitmapWidth || height < bitmapHeight) {
                final float ratio = (float) bitmapWidth / bitmapHeight;
    
                if (bitmapWidth > bitmapHeight) {
                    height = (int) (width / ratio);
                } else if (bitmapHeight > bitmapWidth) {
                    width = (int) (height * ratio);
                }
    
                final Bitmap.Config c = (width == sIconWidth && height == sIconHeight) ?
                        bitmap.getConfig() : Bitmap.Config.ARGB_8888;
                final Bitmap thumb = Bitmap.createBitmap(sIconWidth, sIconHeight, c);
                final Canvas canvas = sCanvas;
                final Paint paint = sPaint;
                canvas.setBitmap(thumb);
                paint.setDither(false);
                paint.setFilterBitmap(true);
                sBounds.set((sIconWidth - width) / 2, (sIconHeight - height) / 2, width, height);
                sOldBounds.set(0, 0, bitmapWidth, bitmapHeight);
                canvas.drawBitmap(bitmap, sOldBounds, sBounds, paint);
                return thumb;
            } else if (bitmapWidth < width || bitmapHeight < height) {
                final Bitmap.Config c = Bitmap.Config.ARGB_8888;
                final Bitmap thumb = Bitmap.createBitmap(sIconWidth, sIconHeight, c);
                final Canvas canvas = sCanvas;
                final Paint paint = sPaint;
                canvas.setBitmap(thumb);
                paint.setDither(false);
                paint.setFilterBitmap(true);
                canvas.drawBitmap(bitmap, (sIconWidth - bitmapWidth) / 2,
                        (sIconHeight - bitmapHeight) / 2, paint);
                return thumb;
            }
        }

        return bitmap;
    }
}

//Android Matrix类实现镜像方法
public void drawRegion(Image image_src,

int x_src, int y_src,

int width, int height,

int transform,

int x_dest, int y_dest,

int anchor){

if((anchor&VCENTER) != 0){

y_dest -= height/2;

}else if((anchor&BOTTOM) != 0){

y_dest -= height;

}

if((anchor&RIGHT) != 0){

x_dest -= width;

}else if((anchor&HCENTER) != 0){

x_dest -= width/2;

}

Bitmap newMap = Bitmap.createBitmap(image_src.getBitmap(), x_src, y_src, width, height);

Matrix mMatrix = new Matrix();

Matrix temp = new Matrix();

Matrix temp2 = new Matrix();

float[] mirrorY = {

-1, 0, 0,
0, 1, 0,
0, 0, 1

};

temp.setValues(mirrorY);

switch(transform){

case Sprite.TRANS_NONE:

break;

case Sprite.TRANS_ROT90:

mMatrix.setRotate(90,width/2, height/2);

break;

case Sprite.TRANS_ROT180:

mMatrix.setRotate(180,width/2, height/2);

break;

case Sprite.TRANS_ROT270:

mMatrix.setRotate(270,width/2, height/2);

break;

case Sprite.TRANS_MIRROR:

mMatrix.postConcat(temp);

break;

case Sprite.TRANS_MIRROR_ROT90:

mMatrix.postConcat(temp);

mMatrix.setRotate(90,width/2, height/2);

break;

case Sprite.TRANS_MIRROR_ROT180:

mMatrix.postConcat(temp);

mMatrix.setRotate(180,width/2, height/2);

break;

case Sprite.TRANS_MIRROR_ROT270:

mMatrix.postConcat(temp);

mMatrix.setRotate(270,width/2, height/2);

break;

}

mMatrix.setTranslate(x_dest, y_dest);

canvas.drawBitmap(newMap, mMatrix, mPaint);

}

//图片Url保存为位图并进行缩放操作
//通过传入图片url获取位图方法
public Bitmap returnBitMap(String url) {
        URL myFileUrl = null;
        Bitmap bitmap = null;
        try {
            myFileUrl = new URL(url);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
        try {
            HttpURLConnection conn = (HttpURLConnection) myFileUrl
                    .openConnection();
            conn.setDoInput(true);
            conn.connect();
            InputStream is = conn.getInputStream();
            bitmap = BitmapFactory.decodeStream(is);
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        Log.v(tag, bitmap.toString());

        return bitmap;
    }
//通过传入位图,新的宽.高比进行位图的缩放操作
public static Drawable resizeImage(Bitmap bitmap, int w, int h) {

        // load the origial Bitmap
        Bitmap BitmapOrg = bitmap;

        int width = BitmapOrg.getWidth();
        int height = BitmapOrg.getHeight();
        int newWidth = w;
        int newHeight = h;

        Log.v(tag, String.valueOf(width));
        Log.v(tag, String.valueOf(height));

        Log.v(tag, String.valueOf(newWidth));
        Log.v(tag, String.valueOf(newHeight));

        // calculate the scale
        float scaleWidth = ((float) newWidth) / width;
        float scaleHeight = ((float) newHeight) / height;

        // create a matrix for the manipulation
        Matrix matrix = new Matrix();
        // resize the Bitmap
        matrix.postScale(scaleWidth, scaleHeight);
        // if you want to rotate the Bitmap
        // matrix.postRotate(45);

        // recreate the new Bitmap
        Bitmap resizedBitmap = Bitmap.createBitmap(BitmapOrg, 0, 0, width,
                height, matrix, true);

        // make a Drawable from Bitmap to allow to set the Bitmap
        // to the ImageView, ImageButton or what ever
        return new BitmapDrawable(resizedBitmap);

    }

1.图片加载方法，方便用户加载图片
/***
* 加载本地图片
* @param context：主运行函数实例
* @param bitAdress：图片地址，一般指向R下的drawable目录
* @return
*/
public final Bitmap CreatImage(Context context, int bitAdress) {
Bitmap bitmaptemp = null;
bitmaptemp = BitmapFactory.decodeResource(context.getResources(),
bitAdress);
return bitmaptemp;
}
2.图片平均分割方法，将大图平均分割为N行N列，方便用户使用
/***
* 图片分割
*
* @param g
* ：画布
* @param paint
* ：画笔
* @param imgBit
* ：图片
* @param x
* ：X轴起点坐标
* @param y
* ：Y轴起点坐标
* @param w
* ：单一图片的宽度
* @param h
* ：单一图片的高度
* @param line
* ：第几列
* @param row
* ：第几行
*/
public final void cuteImage(Canvas g, Paint paint, Bitmap imgBit, int x,
int y, int w, int h, int line, int row) {
g.clipRect(x, y, x + w, h + y);
g.drawBitmap(imgBit, x – line * w, y – row * h, paint);
g.restore();
}
3.图片缩放，对当前图片进行缩放处理
/***
* 图片的缩放方法
*
* @param bgimage
* ：源图片资源
* @param newWidth
* ：缩放后宽度
* @param newHeight
* ：缩放后高度
* @return
*/
public Bitmap zoomImage(Bitmap bgimage, int newWidth, int newHeight) {
// 获取这个图片的宽和高
int width = bgimage.getWidth();
int height = bgimage.getHeight();
// 创建操作图片用的matrix对象
Matrix matrix = new Matrix();
// 计算缩放率，新尺寸除原始尺寸
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// 缩放图片动作
matrix.postScale(scaleWidth, scaleHeight);
Bitmap bitmap = Bitmap.createBitmap(bgimage, 0, 0, width, height,
matrix, true);
return bitmap;
}
4.绘制带有边框的文字，一般在游戏中起文字的美化作用
/***
* 绘制带有边框的文字
*
* @param strMsg
* ：绘制内容
* @param g
* ：画布
* @param paint
* ：画笔
* @param setx
* ：：X轴起始坐标
* @param sety
* ：Y轴的起始坐标
* @param fg
* ：前景色
* @param bg
* ：背景色
*/
public void drawText(String strMsg, Canvas g, Paint paint, int setx,
int sety, int fg, int bg) {
paint.setColor(bg);
g.drawText(strMsg, setx + 1, sety, paint);
g.drawText(strMsg, setx, sety – 1, paint);
g.drawText(strMsg, setx, sety + 1, paint);
g.drawText(strMsg, setx – 1, sety, paint);
paint.setColor(fg);
g.drawText(strMsg, setx, sety, paint);
g.restore();
}
5.Android 图片透明度处理代码
/**
* 图片透明度处理
*
* @param sourceImg
*            原始图片
* @param number
*            透明度
* @return
*/
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 & 0×00FFFFFF);// 修改最高2位的值
}
sourceImg = Bitmap.createBitmap(argb, sourceImg.getWidth(), sourceImg.getHeight(), Config.ARGB_8888);
return sourceImg;
}
6.图片翻转
Resources res = this.getContext().getResources();
img = BitmapFactory.decodeResource(res, R.drawable.slogo);
Matrix matrix = new Matrix();
matrix.postRotate(90);        /*翻转90度*/
int width = img.getWidth();
int height = img.getHeight();
r_img = Bitmap.createBitmap(img, 0, 0, width, height, matrix, true);

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;
import android.graphics.Shader.TileMode;
import android.graphics.drawable.Drawable;
/**
* 
* @author superdev
* @version 1.0
*
*/
public class ImageUtil {

/**
* 放大缩小图片
*/
public static Bitmap zoomBitmap(Bitmap bitmap, int w, int h) {
   int width = bitmap.getWidth();
   int height = bitmap.getHeight();
   Matrix matrix = new Matrix();
   float scaleWidht = ((float) w / width);
   float scaleHeight = ((float) h / height);
   matrix.postScale(scaleWidht, scaleHeight);
   Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);
   return newbmp;
}

/**
* 将Drawable转化为Bitmap
*/
public static Bitmap drawableToBitmap(Drawable drawable) {
   int width = drawable.getIntrinsicWidth();
   int height = drawable.getIntrinsicHeight();
   Bitmap bitmap = Bitmap.createBitmap(width, height, drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565);
   Canvas canvas = new Canvas(bitmap);
   drawable.setBounds(0, 0, width, height);
   drawable.draw(canvas);
   return bitmap;

}

/**
* 获得圆角图片的方法
*/
public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, float roundPx) {

   Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);
   Canvas canvas = new Canvas(output);

   final int color = 0xff424242;
   final Paint paint = new Paint();
   final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
   final RectF rectF = new RectF(rect);

   paint.setAntiAlias(true);
   canvas.drawARGB(0, 0, 0, 0);
   paint.setColor(color);
   canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

   paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
   canvas.drawBitmap(bitmap, rect, rect, paint);

   return output;
}

/**
* 获得带倒影的图片方法
*/
public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap) {
   final int reflectionGap = 4;
   int width = bitmap.getWidth();
   int height = bitmap.getHeight();

   Matrix matrix = new Matrix();
   matrix.preScale(1, -1);

   Bitmap reflectionImage = Bitmap.createBitmap(bitmap, 0, height / 2, width, height / 2, matrix, false);

   Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height / 2), Config.ARGB_8888);

   Canvas canvas = new Canvas(bitmapWithReflection);
   canvas.drawBitmap(bitmap, 0, 0, null);
   Paint deafalutPaint = new Paint();
   canvas.drawRect(0, height, width, height + reflectionGap, deafalutPaint);

   canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);

   Paint paint = new Paint();
   LinearGradient shader = new LinearGradient(0, bitmap.getHeight(), 0, bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);
   paint.setShader(shader);
   // Set the Transfer mode to be porter duff and destination in
   paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
   // Draw a rectangle using the paint with our linear gradient
   canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() + reflectionGap, paint);
   return bitmapWithReflection;
}
}

private byte[] Bitmap2Bytes(Bitmap bm){
   ByteArrayOutputStream baos = new ByteArrayOutputStream();
   bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
   return baos.toByteArray();
}
private Bitmap Bytes2Bimap(byte[] b){
            if(b.length!=0){
                return BitmapFactory.decodeByteArray(b, 0, b.length);
            }
            else {
                return null;
            }
      }

 /**
     * create the bitmap from a byte array
     *生成水印图片
     * @param src the bitmap object you want proecss
     * @param watermark the water mark above the src
     * @return return a bitmap object ,if paramter's length is 0,return null
     */
    private Bitmap createBitmap( Bitmap src, Bitmap watermark )
    {
        String tag = "createBitmap";
        Log.d( tag, "create a new bitmap" );
        if( src == null )
        {
            return null;
        }
 
        int w = src.getWidth();
        int h = src.getHeight();
        int ww = watermark.getWidth();
        int wh = watermark.getHeight();
        //create the new blank bitmap
        Bitmap newb = Bitmap.createBitmap( w, h, Config.ARGB_8888 );//创建一个新的和SRC长度宽度一样的位图
        Canvas cv = new Canvas( newb );
        //draw src into
        cv.drawBitmap( src, 0, 0, null );//在 0，0坐标开始画入src
        //draw watermark into
        cv.drawBitmap( watermark, w - ww + 5, h - wh + 5, null );//在src的右下角画入水印
        //save all clip
        cv.save( Canvas.ALL_SAVE_FLAG );//保存
        //store
        cv.restore();//存储
        return newb;
    }
   /** 重新编码Bitmap
   * 
   * @param src
   *          需要重新编码的Bitmap
   *
   * @param format
   *          编码后的格式（目前只支持png和jpeg这两种格式）
   *
   * @param quality
   *          重新生成后的bitmap的质量
   *
   * @return
   *          返回重新生成后的bitmap
   */
 private static Bitmap codec(Bitmap src, Bitmap.CompressFormat format,
                                    int quality) {
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            src.compress(format, quality, os);            

            byte[] array = os.toByteArray();
            return BitmapFactory.decodeByteArray(array, 0, array.length);
        }

//Stream转换成Byte
static byte[] streamToBytes(InputStream is) {
      ByteArrayOutputStream os = new ByteArrayOutputStream(1024);
      byte[] buffer = new byte[1024];
      int len;
      try {
             while ((len = is.read(buffer)) >= 0) {
             os.write(buffer, 0, len);
             }
          } catch (java.io.IOException e) {

          }
          return os.toByteArray();
}
//把View转换成Bitmap

    /**
     * 把一个View的对象转换成bitmap
     */
    static Bitmap getViewBitmap(View v) {
        
        v.clearFocus();
        v.setPressed(false);

        //能画缓存就返回false
        boolean willNotCache = v.willNotCacheDrawing();
        v.setWillNotCacheDrawing(false); 
        int color = v.getDrawingCacheBackgroundColor();
        v.setDrawingCacheBackgroundColor(0);
        if (color != 0) {
            v.destroyDrawingCache();
        }
        v.buildDrawingCache();
        Bitmap cacheBitmap = v.getDrawingCache();
        if (cacheBitmap == null) {
            Log.e(TAG, "failed getViewBitmap(" + v + ")", new RuntimeException());
            return null;
        }
        Bitmap bitmap = Bitmap.createBitmap(cacheBitmap);
        // Restore the view
        v.destroyDrawingCache();
        v.setWillNotCacheDrawing(willNotCache);
        v.setDrawingCacheBackgroundColor(color);
        return bitmap;
    }

读取raw资源文件中的mp3文件，然后通过音乐播放器播放：

    /**
     * 把mp3文件写入卡
     * 
     * @param fileName
     *             输出的文件名（全路径）
     * @param context
         *             context对象
     */
    private void writeMP3ToSDcard(String fileName, Context context) {
        byte[] buffer = new byte[1024 * 8];
        int read;
        BufferedInputStream bin = new BufferedInputStream(context.getResources().openRawResource(R.raw.ring));
        try {
            BufferedOutputStream bout = new BufferedOutputStream(new FileOutputStream(fileName));
            while ((read = bin.read(buffer)) > -1) {
                bout.write(buffer, 0, read);
            }
            bout.flush();
            bout.close();
            bin.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


Intent intent = new Intent();
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.setAction(android.content.Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(newFile("XXXXmp3的文件全路径")),"audio/*");
startActivity(intent);

绘制图像倒影

private void  
_Init()   
{   
  m_paint = new Paint(Paint.ANTI_ALIAS_FLAG);   
  LinearGradient lg = new LinearGradient(   
    0, 0, 0, m_nShadowH,    
    0xB0FFFFFF, 0x00000000,   
    Shader.TileMode.CLAMP);   
  m_paint.setShader(lg);   
  m_paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.MULTIPLY));   
}   
  
@Override protected void    
onDraw(Canvas canvas)   
{   
  super.onDraw(canvas);   
  
  int nX = 0;   
  int nY = 20;   
  
  _DrawNormalImg(canvas, nX, nY);   
  _DrawMirror(canvas, nX, nY);   
}    
  
private void  
_DrawNormalImg(Canvas canvas, int nX, int nY)   
{   
  canvas.save(Canvas.MATRIX_SAVE_FLAG);   
  canvas.translate(nX, nY);      
  m_dw.draw(canvas);   
  canvas.restore();   
}   
  
private void  
_DrawMirror(Canvas canvas, int nX, int nY)   
{   
  int nW = m_dw.getIntrinsicWidth();   
  int nH = m_dw.getIntrinsicHeight();   
  
  ///////////////////////////////////   
  //draw mirror image   
  canvas.save(Canvas.MATRIX_SAVE_FLAG);   
  canvas.scale(1.0f, -1.0f);   
  canvas.translate(nX, -(nY + nH * 2));   
  canvas.clipRect(0, nH, nW, nH - m_nShadowH);   
  m_dw.draw(canvas);   
  canvas.restore();   
  
  //////////////////////////////   
  //draw mask   
  canvas.save();   
  canvas.translate(nX, nY + nH);   
  canvas.drawRect(0, 0, nW, m_nShadowH, m_paint);   
  canvas.restore();   
}  

Android 繪圖座標體系預設的原點在左上角，X 軸往右是越來越大的正值，而 Y 軸往下，則是越來越大的正值。要畫出垂直翻轉的圖片，其實也就是要垂直翻轉整個繪圖座標體系。在 Android 中，要如何做？答案就是 canvas.scale(1.0f, -1.0f)。很簡單吧，沒想到給 scale() 函式一個負值，就可以翻轉相對應的軸。
在 Photoshop 中，做鏡像特效的第二步是要對這翻轉的圖片，加個由灰到黑的漸層 mask。
在 Android 中，要畫漸層色，那就一定得用 LinearGradient 這個類別。至於要對背景圖加上個 mask，就請參考一下 Paint 的 setXfermode() 函式。_Init() 這個函式，就是負責生成一個由灰到黑漸層 mask 的 m_paint 物件。

http://blog.csdn.net/Android_Tutor/archive/2010/11/02/5981753.aspx

http://www.cnblogs.com/TerryBlog/archive/2012/01/08/2316482.html

android常用图片特效处理
http://www.eoeandroid.com/thread-170526-1-1.html

相机（Camera）实时滤镜效果
http://www.eoeandroid.com/thread-171528-1-1.html

Android, WindowsPhone7, IOS ,vc2010平台40多套图片滤镜开源
http://www.cnblogs.com/daizhj/archive/2012/05/15/2501406.html

Android实现获取本机中所有图片
http://www.cnblogs.com/hanyonglu/archive/2012/05/10/2494908.html