Assuming the image size is a multiple of the block size (8x8, 16x8, or 16x16 depending on the chroma subsampling), lossless rotation of JPEGs is possible, e.g.

Assuming the image size is a multiple of the block size (8x8, 16x8, or 16x16 depending on the chroma subsampling), lossless rotation of JPEGs is possible, e.g. with jpegtran: http://jpegclub.org/jpegtran/ http://jpegclub.org/jpegtran/