Export of JPG previews

[MichaelEzra]

Axel, this is a wonderful new feature!
One of the uses of the JPG preview export is for stitching of draft preview-quality panoramas. The stitching software uses the EXIF information. Would it be possible to have an option to retain the EXIF in the extracted preview JPGs?
Thanks!

[Axel]

Thanks! I've just posted an update to the File Utilities plug-in, with slightly better performance and which fixes an elusive bug that seldom occurs on multi-processing machines.

EXIF info cannot be moved as-is when changing the format, size etc, and it would add considerable weight to the images (several KB, which would for double or triple the size of thumbnails). For web use the files are better kept as small as possible.

Besides that I wonder what EXIF data an autosticher would use, the date/time to help with sorting the images in proper sequence? Also, are you using Microsoft ICE? If not, try it!

Finally, technically, this is not an "export of JPEG previews". The plug-in create entirely new files on its own and does not depend on the presence of any kind of preview or JPEG data in the source files: it works with any input format, raw and non raw.

[MichaelEzra]

I am using Autopano Giga (autopano.net) The exposure-related setting, focal length and the lens information, camera model (hence sensor size and crop factor, focal length multiplier) are used for proper stitching. May be more, not entirely sure.

I currently shoot RAW + smallest JPG. these JPG-s have full exif, so they are being used for very fast panorama recognition & preview renderings.

[malch]

I would also vote for the ability to copy the EXIF to the JPEG, at least as an option.

Otherwise... Phil Harvey's Exiftool is a handy utility that will allow you to copy the EXIF from a RAW file to the corresponding JPEG (plus a million other things). It has a command line interface and this means it's easy to incorporate into scripts and other automated workflows.

[Axel]

Just tried ExifTool, transferred all metadata from a NEF to a JPEG and the first thing is that many fields are missing after the transfer (81 in NEF and 47 in the JPEG). This is not surprising as the metadata schemas between JPEG and everything else are different, every fields must be hand-picked and moved individually. The MakerNote was there intact though.

The main issue was that the file grew up 27KB after adding some D3 metadata. This is an enourmous weight to add to files saved for web use, especially to 6KB thubmnails or ~50-60KB 640 pixels images.

[malch]

Just tried ExifTool, transferred all metadata from a NEF to a JPEG and the first thing is that many fields are missing after the transfer (81 in NEF and 47 in the JPEG).

Hmmm, that's not close to what I'm getting. I used:

C:\ZIP>exiftool -tagsfromfile DSE_5463.nef -r -overwrite_original -ext JPG C:/ZIP/new.jpg

To list all of the meta data in each image, I used:

exiftool -a -u -g1 new.jpg > new.txt

I'm not sure how you counted the fields; obviously the preview images embedded within the NEF are not going to be copied over. Did you allow for that?

Your concerns about the impact of the metadata on the file size are very reasonable, especially if publishing 50-60KBytes images. However, I personally don't think that deleting ALL of the meta data is the right solution. Personally, I'd prefer to define a core set of basic fields; retain those and strip the rest. Off the top of my head... DateTimeOriginal, Camera, Lens, Shutter, Aperture, Copyright. Maybe location and GPS data.

It seems to me that the classic Save for Web tends to throw out the baby with the bathwater