|Exif TIFF Tag PixelYDimension|
TIFF Tag Reference
TIFF Tag PixelYDimension
Specific to compressed data; the valid height of the meaningful image.
When a compressed file is recorded, the valid height of the meaningful image shall be recorded in this tag, whether or not there is padding data or a restart marker. This tag should not exist in an uncompressed file.
Since data padding is unnecessary in the vertical direction, the number of lines recorded in this valid image height tag will in fact be the same as that recorded in the SOF.