Reading EXIF data from raw files

[simsurace]

ExifViewer seems to be unable to read EXIF data from some raw files (I tried with .NEF, don't know if this generalized to other formats). Is this a limitation of libexif (it does not seem to be, since libexif mentions .NEF files in several places)? How come the wrapper just returns an empty Dict?

[ashwanirathee]

Hey @simsurace, It doesn't work with .NEF yet

[simsurace]

Do you know why? Does it work with other formats?

[ufechner7]

Perhaps it is this bug:
https://sourceforge.net/p/libexif/bugs/88/

[MendeBadra]

I can't read exif tags from .TIF files also

[ufechner7]

@MendeBadra Can you share a .tif file where it doesn't work?

[MendeBadra]

Ok. Here is the images:

Bad_10.zip

And when I ran in julia v1.10 with FileIO and ExifViewer loaded :

julia> io = open("DJI_0741.TIF", "r")
IOStream(<file DJI_0741.TIF>)
julia> blue = load(io)
[ Info: Precompiling TiffImages [731e570b-9d59-4bfa-96dc-6df516fadf69]
1300×1600 Matrix{ColorTypes.Gray{FixedPointNumbers.N0f16}}:

and able to load the image fine. But the exif tags can't be accessed:

blue_meta = read_tags(io; read_all=true)
Dict{String, String}()

But the images do really have exif tags, can be read using exiftool

shell> exiftool DJI_0741.TIF
ExifTool Version Number         : 12.89
File Name                       : DJI_0741.TIF
Directory                       : .
File Size                       : 4.2 MB