In my experience this mainly occurs with JPEG images. Converting the correctly rotated version to PNG beforehand with any respectable image editor or converter should resolve this issue (that is, if you don’t mind the image size increasing). PNG does technically support this metadata as of 2017, but it’s not nearly used as commonly as with JPEG.
Lemmy strips the metadata, including rotation angle.
In my experience this mainly occurs with JPEG images. Converting the correctly rotated version to PNG beforehand with any respectable image editor or converter should resolve this issue (that is, if you don’t mind the image size increasing). PNG does technically support this metadata as of 2017, but it’s not nearly used as commonly as with JPEG.