bitmap

package com.android.tutor; 
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; 
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; 
    } 
     
}