If you are going to experiment with editing raw files, some risk factors: >From reading Phil's exif web site, and other stuff I didn't bookmark corruption risk:
Safest: 1. Editing standard metadata (Exif, ITPC) replacing a value with one of the same size. Image orientation would be one of these, I think, having a value of 0-3 (but check the range. Suppose it is 0 to3 and you put in 5? Will other software ignore it, only pay attention to the smallest two bits of the number, interpreting it as a 1, go wandering off into a cloud of blue bits and crash?) 2. Editing standard metadata replacing a value with one that is smaller. Some fields are text strings, and so can be padded with blanks, changing the problem to that of problem 1. 3. Editing makernotes data. This is propriatary to the camara maker, and it's format can vary with both model and firmware version. 4. Editing preview images. The big risk here is that the size of the preview will change, and whatever you edit with won't leave the end of the data in the same place, potentially clobbering the front end of the raw data. 5. Editing uncompressed raw data. 6. Editing compressed raw data. Most risky. One of my ideas is to deliberately in my camera put an extended copyright notice such as Copyright S. G. Botsford 2020 -- Image ID Nikon-D7100-S.7614346-XXXX-XXXX-XXXX-XXXX-XXXX Then, with a script read the exif date, and the shutter count, and replace the string of X's with the date and shutter count. This gives a unique ID trackable back to me for the image. I don't know if all cameras write an ITPC core section in the meta data, or if this field is in the maker notes. In all derived files, copy this information to a few other fields. Not all photo editors respect metadata. Your image database tracks this. * You edited a bunch of images with Photoshop, saved under different names. -- you still have a way to connect the .PSD, the resulting TIFF with the original RAW. * Your assistant used a file browser to "organize" your image archive. -- you can reconnect xmp files with masters. * Your database has crashed, taking everything with it. XMP files can be reconnected with masters even if names are in doubt. * You exported a bunch of images. Someone wants a modification that will work better if starting from the original. It doesn't work for all cameras. iPhones don't have a shutter count, nor AFAIK a raw format available to the public. Regards Sherwood On Wed, 29 Jan 2020 at 05:43, Patrick Shanahan <[email protected]> wrote: > * Myron Gochnauer <[email protected]> [01-29-20 03:05]: > > Several people suggested trying exiftool… carefully!! (I’ve been burned > often enough to know you only experiment on copies.) > > > > Anyway, exiftool -a -u -g1 {fname} showed the following results: > > > > “Orientation : Horizontal (normal)” - - - in exif of NEF landscape > format image file. > > > > "Orientation : Rotate 270 CW” - - - in exif of RAF portrait format image > file. > > > > I’ll see if I can figure out how to edit those values. (I’m a total > newbie with exiftool.) > > > > It *does* seem like there is a place for a GUI app, complete with error > checking, for altering exif information. If nothing else, I’m pretty sure > that *everyone* sooner or later produces a bunch of images with last year’s > copyright information, the wrong time, or some other annoying error. > > A "mantra" of darktable is to not touch in any way the "raw" image. > Editing with exiftool or exiv2 both will make changes to the "raw" image > file with unknown now or future consequences. > > You by using darktable have opted to use a photo editor which does not > change in any way the "raw" image. Why contradict that by makeing changes > with another apt? > > It is no more work to rotate the images using darktable. And darktable > will store the image orientation that you determine within the xmp file > and the library. Maintain backups of your library and your raw image > files and their accompanying xmp files and your orientation will also be > retained. > > Do what you want with exported images, you have an original now so you can > always make another. > > And a bonus, no need to research exiftool/exiv2 and craft commandline > parameters to rotate your images. > > ps: does your chosen email client not make line wrapping available for > you? Maybe time to change. > > > -- > (paka)Patrick Shanahan Plainfield, Indiana, USA @ptilopteri > http://en.opensuse.org openSUSE Community Member facebook/ptilopteri > Photos: http://wahoo.no-ip.org/piwigo paka @ IRCnet freenode > > ____________________________________________________________________________ > darktable user mailing list > to unsubscribe send a mail to > [email protected] > > ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to [email protected]
