图片压缩的方法

参考下面的

http://www.oschina.net/code/snippet_726985_22365

http://gundumw100.iteye.com/blog/849729(好）

/**
     * compress bitmap to less than long size,可以再研究
     * @param bitmap
     * @param long  size
     * @return compressed bitmap
     */
    public static Bitmap compressBitmap(Bitmap bitmap, long size ){
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG,100 , baos);//100表示不压缩,压缩后放在baos中
        Log.i("before compress", String.valueOf( baos.toByteArray().length/1024));
        
        if (bitmap==null|| baos.toByteArray().length<=size){
            Log.i("before", "bitmap null or < size");
            return bitmap;  //已经很小了
        }    
        
        int compressRatio=100; //压缩
        while (baos.toByteArray().length>size) {//如果压缩后大于100k，再压缩
            baos.reset();
            compressRatio=compressRatio-3;
            if(compressRatio<=10){
                Log.i("compress", "break in while");
                break;
            }        
            bitmap.compress(Bitmap.CompressFormat.JPEG,compressRatio , baos);
            Log.i("compress", "in while "+String.valueOf(baos.toByteArray().length/1024));
        }
        Log.i("after, baos ",String.valueOf(baos.toByteArray().length/1024));
        ByteArrayInputStream bois = new ByteArrayInputStream(baos.toByteArray());
        Bitmap newBitmap= BitmapFactory.decodeStream(bois,null,null);
        bitmap.recycle();
        return newBitmap;
    }
    
    public static long getSizeofBitmap(Bitmap bitmap) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);// 100表示不压缩质量
        long size = baos.toByteArray().length ;// 读出图片的kb大小
        return size;
    }