Is it possible to set gif image's tags using the windows properties pannel ? It currently seems working on jpg, but not on gif files.
GIF files don't support EXIF tags and here's why.
There is a great misconception about JPEG files. Actually, JPEG isn't an image file format - it's a compression algorithm. JPEG specs don't describe how to pack compressed image into file. There are two (mostly compatible) formats for that: the older JFIF and the newer EXIF. Most modern software will also accept mixed formats.
So EXIF isn't a tagging system. Entire JPEG image files are in fact EXIF (or JFIF) files and tagging is one of EXIF's features. GIFs don't use EXIF at all, so you can't put EXIF tags on them.
I always turn to ExifTool for all my tagging needs. The following command will allow you to update the Comment tag:
exiftool -comment="This is a comment!" Sample.gif
For example, to specify FlashMode (integer) as Off you can use (note the #):
exiftool -FlashMode#=2 Sample.gif
To specify FlashFired (boolean) as False, use:
exiftool -FlashFired=false Sample.gif
and so on.
Note: -FlashMode is a shortcut for -XMP-exif:FlashMode. See the ExifTool documentation for details. Also, I don't currently know of any way to make Windows aware of these tags though. Maybe there's a shell extension available, will update this answer if I find one.
EXIF is a data collection system used in jpeg files taken on cameras to provide state information (thumbnail, exposure, ISO speed, date, time, location, etc) about when the picture was taken. Since it is native to this type of file, Windows allows manipulation of a subset of the data (similar to MP3 file tags). Other files that can have EXIF information are TIFF and WAV files
GIF is an older format that may have text headers, but the format never was extended to include EXIF information.