For JPEG this is the EXIF Orientation flag: https://jdhao.github.io/2019/07/31/image_rotation_exif_info/ https://jdhao.github.io/2019/07/31/image_rotation_exif_

For JPEG this is the EXIF Orientation flag: https://jdhao.github.io/2019/07/31/image_rotation_exif_info/ https://jdhao.github.io/2019/07/31/image_rotation_exif_info/ It allows the camera to write almost its output without considering how you're holding the camera, and then write just three bits to indicate how it should be displayed. (It should be two bits, since the third logical bit is for mirroring, except the specific flag values they chose for the non-mirrored rotations were 0x0, 0x2, 0x5, and 0x7.)