图片的圆角和颜色处理

忘了转载自哪里，从以前的文档里找出来的，原作者看到莫怪莫怪

图片本身加上圆角

Bitmap myCoolBitmap = ... ; // <-- Your bitmap you want rounded 
int w = myCoolBitmap.getWidth(), h = myCoolBitmap.getHeight(); 

Bitmap rounder = Bitmap.createBitmap(w,h,Bitmap.Config.ARGB_8888); 
Canvas canvas = new Canvas(rounder);   

Paint xferPaint = new Paint(Paint.ANTI_ALIAS_FLAG); 
xferPaint.setColor(Color.RED); 

canvas.drawRoundRect(new RectF(0,0,w,h), 20.0f, 20.0f, xferPaint); 

xferPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN)); 
canvas.drawBitmap(myCoolBitmap, 0,0, null); 
canvas.drawBitmap(rounder, 0, 0, xferPaint); 
或者
public static Bitmap getRoundedCornerBitmap(Bitmap bitmap) {
    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);
    final float roundPx = 12;

    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;
}

将彩色图转换为灰度图 

/** 
         * 将彩色图转换为灰度图 
         * @param img 位图 
         * <a href="\"http://www.eoeandroid.com/home.php?mod=space&uid=7300\"" target="\"_blank\"">@return</a>  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; 
        } 

记录一下，方便自己查阅