Android 图像处理(类型转换,比例缩放,倒影,圆角)的小例子

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;    
    }

 

 

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;    
    }

 

 

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;    
    } 

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; 
}