raw processing on Linux - retain EXIF?

Has anyone written a workflow script that uses
ExifTool (http://www.sno.phy.queensu.ca/~phil/exiftool/)
to transfer the appropriate EXIF tags from the RAW
file to the output JPEG file when using
DCRAW (http://cybercom.net/~dcoffin/dcraw/) ?

In general, the "-TagsFromFile" option
is a good "first approximation, but some
tags would need altering or creating
(e.g. White Balance, Compression, colour space,
and any colour temperature assumptions
made during the use of DCraw)

The aim, of course, if a JPEG with
full and accurate EXIF.

BugBear

bugbear <bugbear@trim_papermule.co.uk_trim> wrote:
>Has anyone written a workflow script that uses
>ExifTool (http://www.sno.phy.queensu.ca/~phil/exiftool/)
>to transfer the appropriate EXIF tags from the RAW
>file to the output JPEG file when using
>DCRAW (http://cybercom.net/~dcoffin/dcraw/) ?
>
>In general, the "-TagsFromFile" option
>is a good "first approximation, but some
>tags would need altering or creating
>(e.g. White Balance, Compression, colour space,
>and any colour temperature assumptions
>made during the use of DCraw)
>
>The aim, of course, if a JPEG with
>full and accurate EXIF.

One script that I use primarily to rotate images for
correct orientation according to the EXIF tag, or
lacking a tag by checking horizontal vs. vertical size
also makes an attempt at that "first approximation".

It rotates the image (using /convert/), and then tries
to verify EXIF data and will copy it from the original
JPEG file or from an NEF file if the JPEG is lacking.
Other than changing the flagged orientation to match, it
makes no attempt at updating tags though.

I use /ufraw/ rather than /dcraw/, but the script is
generic in that sense.

Is that of any use to you?

I'm not sure how significant it is with other cameras,
but with Nikon there is a rather large difference
between the EXIF data in a JPEG output file compared to
an NEF output file.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com

bugbear wrote:
> Has anyone written a workflow script that uses
> ExifTool (http://www.sno.phy.queensu.ca/~phil/exiftool/)
> to transfer the appropriate EXIF tags from the RAW
> file to the output JPEG file when using
> DCRAW (http://cybercom.net/~dcoffin/dcraw/) ?
>
> In general, the "-TagsFromFile" option
> is a good "first approximation, but some
> tags would need altering or creating
> (e.g. White Balance, Compression, colour space,
> and any colour temperature assumptions
> made during the use of DCraw)
>
> The aim, of course, if a JPEG with
> full and accurate EXIF.
>
> BugBear

I wrote my own Perl scripts many years ago. My Canon 300D does not
record the EXIF tags in the RAW file, rather in the THM file. I use
dcraw and Image Magic (convert) to create a small (1024 x 1024) jpeg.
exifcopy (http://www.hugsan.com/EXIFutils/) to copy all EXIF and IPTC
data and Image::IPTCInfo to set some IPTC attributes followed by jhead
(http://www.sentex.net/~mwandel/jhead) is used to automatically rotate
the image based on the EXIF orientation tag. This and more occurs
within the same script which downloads from the card to the hard drive
which includes a backup copy of the raw file to an external server.

However, since I do not use my converted jpegs for anything other than
keyword tagging and previewing, I do not alter the tags for WB or color
as I use dcraw with the following options: -m -t 0 -w -c

--

Len