Can a JPEG compressed image be rotated without a loss in quality?

Question

JPEG is a lossy compression scheme, so decompression-manipulation-recompression normally reduces the image quality further for each step. Is it possible to rotate a

Answer 1

Unless you rotate by multiples of 90 degrees then your image will have to perform some kind of interpolation which might reduce the quality of your image. Using a good interpolation algorithm will help here.

As for opening and recompressing, I am not sure you would actually get worse quality, but then I am not sure exactly how JPEG works.

I suggest you try to compress, manipulate and recompress and see for yourself if the result is good enough. What is good enough is subject to your application.