图片的圆角和颜色处理

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
* @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;
}