android - onPictureTaken 后旋转 JPEG 的字节数组

Question

有没有办法在不将字节数组解码为位图的情况下旋转字节数组？

目前在 jpeg PictureCallback 中，我只是将字节数组直接写入文件。但是图片是旋转的。我想在不解码为位图的情况下旋转它们，希望这样可以节省我的内存。

    BitmapFactory.Options o = new BitmapFactory.Options();
    o.inJustDecodeBounds = true;
    BitmapFactory.decodeByteArray(data, 0, data.length, o);

    int orientation;
    if (o.outHeight < o.outWidth) {
        orientation = 90;
    } else {
        orientation = 0;
    }

    File photo = new File(tmp, "demo.jpeg");

    FileOutputStream fos;
    BufferedOutputStream bos = null;
    try {
        fos = new FileOutputStream(photo);
        bos = new BufferedOutputStream(fos);
        bos.write(data);
        bos.flush();
    } catch (IOException e) {
        Log.e(TAG, "Failed to save photo", e);
    } finally {
        IOUtils.closeQuietly(bos);
    }

Answer 1

试试这个。就解决了这个问题。

Bitmap storedBitmap = BitmapFactory.decodeByteArray(data, 0, data.length, null);

Matrix mat = new Matrix();                        
mat.postRotate("angle");  // angle is the desired angle you wish to rotate            
storedBitmap = Bitmap.createBitmap(storedBitmap, 0, 0, storedBitmap.getWidth(), storedBitmap.getHeight(), mat, true);