图片处理，圆形圆角描边

 1.圆形描边

public static Bitmap getCircleCornerBitmap(Bitmap source,int strokeWidth){
        if (source == null || source.isRecycled()) {
            return null;
        }
        int srcBitmapWidth = source.getWidth();
        int srcBitmapHeight = source.getHeight();
        boolean isY;//是否根据y轴来切
        int targetLength=(isY=srcBitmapWidth<srcBitmapHeight)?srcBitmapWidth:srcBitmapHeight;//取图片较短的边来作为要生成图片的长和宽
        Bitmap targetBitmap=Bitmap.createBitmap(targetLength+strokeWidth*2,targetLength+strokeWidth*2, Bitmap.Config.ARGB_8888);
        Canvas canvas=new Canvas(targetBitmap);
        canvas.save();//保存画布,为画布移动作准备
        canvas.translate(strokeWidth,strokeWidth);//移动画布,为的是生成圆形头像居中
        Paint paint = new Paint();
        paint.setAntiAlias(true);
        RectF dstRectF=new RectF(0,0,targetLength,targetLength);
        canvas.drawRoundRect(dstRectF,targetLength/2,targetLength/2,paint);//创建一个矩阵圆

        Rect srcRect ;//源图片要截取对应的矩阵

        if(isY){
            srcRect = new Rect(0, (srcBitmapHeight-targetLength)/2,targetLength, (srcBitmapHeight-targetLength)/2+targetLength);
        }else{
            srcRect=new Rect((srcBitmapWidth-targetLength)/2,0,(srcBitmapWidth-targetLength)/2+targetLength,targetLength);
        }

        //关键方法,用于合成圆形图片，若有不明白的，可参照：http://blog.youkuaiyun.com/wangduanqing5945/article/details/38796269
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(source,srcRect,dstRectF,paint);
        canvas.restore();//对应canvas.save()来使用,为了恢复画布,为描边做准备

        Paint strokePaint=new Paint();//描边的画笔
        strokePaint.setAntiAlias(true);
        strokePaint.setStyle(Paint.Style.STROKE);
        //透明度5%
        strokePaint.setColor(Color.argb(13, 0, 0, 0));
        strokePaint.setStrokeWidth(strokeWidth);
        canvas.drawCircle(targetLength/2+strokeWidth,targetLength/2+strokeWidth,targetLength/2,strokePaint);//描边就是画一个圆形
        return targetBitmap;

    }

2.圆角

public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int pixels) {
    Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
            bitmap.getHeight(), Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(output);

    final int color = 0xff000000;
    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 = pixels;

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

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

    return output;
}

透明度

100% — FF 
95% — F2 
90% — E6 
85% — D9 
80% — CC 
75% — BF 
70% — B3 
65% — A6 
60% — 99 
55% — 8C 
50% — 80 
45% — 73 
40% — 66 
35% — 59 
30% — 4D 
25% — 40 
20% — 33 
15% — 26 
10% — 1A 
5% — 0D 
0% — 00 
格式如#00FFFFFF，前两位代表不透明度的十六进制。00表示完全透明，FF就是全不透明。依次递增。