XnView Software

Hi,

is it possible to tell XnView which files are companion files? E.g. some raw converters write a kind of "recipe file" for each raw image converted (it contains information on how the raw file was converted the last time it was opened). It would be handy if XnView deleted or moved these companion files when I move or delete the corresponding raws. As XnView will certainly not know which files belong together, it would be handy to configure it individually to one's needs. Or is that already possible?

Thanks
Frank

Anonymous wrote:Hi,

is it possible to tell XnView which files are companion files? E.g. some raw converters write a kind of "recipe file" for each raw image converted (it contains information on how the raw file was converted the last time it was opened). It would be handy if XnView deleted or moved these companion files when I move or delete the corresponding raws. As XnView will certainly not know which files belong together, it would be handy to configure it individually to one's needs. Or is that already possible?

Thanks
Frank

You have option/general/file op/For copy/move use companion file

... sorry I wasn't clear enough. I knew that, Pierre, but how do I tell XnView which files belong together?
Thanks!
Frank

P.S. Just viewed 250+ pictures I've taken an hour ago with XnView and deleted half of them - went really really fast with the incredibly handy tagging feature (and the comparison feature). Great software!

Anonymous wrote:... sorry I wasn't clear enough. I knew that, Pierre, but how do I tell XnView which files belong together?

Why, it's not a standard companion? I need to add settings for that

Frank--

Hi, my name is Ty and I'm working on an improved help file for XnView. I am NOT an XnView expert, and have never heard of companion files until reading your post. Would you be interested in taking a few minutes and writing up a little blurb on companion files that I could put into the help file--what they are, how they're used, how to control them, etc? Or perhaps point me at some existing material on the subject? It would be much appreciated, and will contribute to a better XnView. Thanks.

Hello Ty,

I don't own one of these fancy SLRs, and I have no hands-on experience with DNG/RAW files either, but to show my appreciation for your efforts in building a new help file I gathered some information on the subject:

Forum references:

• Canon RAW: Combine .CRW and .THM files
• Copy XMP with DNG
• Enhanced support for paired Raw/JPEG photos

Off-site resources:

• Wikipedia: Extensible Metadata Platform
• Adobe: Adobe XMP for Creative Professionals » Page 5
• O'Reilly Digital Media Blog: XMP Sidecar Files and Lightroom – Part 1 & Part 2

Thanks, XnTriq. I'll explore these topics and try to come up with a nice synthesis for the help file. Of course, if YOU would like to write such a synthesis, you would be most welcome...!!!

Hi Ty...

I can contribute a little.

Companion files occur in a couple of situations: Raw image editing and non-destructive editing of other file types.

In the first case, a Raw image isn't really a graphics file. Instead, it is the readout from the camera chip (plus some other info) in a format either proprietary to the camera manufacturer or in a format shared between manufacturers (such as AdobeRAW).

Adjustments (brightness, contrast, noise reduction, etc) a photographer makes to a Raw image (using a Raw tool such as Lightroom) typically can't be made directly to the Raw data itself. Changes to the Raw data are recorded as operations on that data in steps that translate it into a displayable image. The operations chosen by the photographer to adjust his raw image are typically stored in "companion" or "sidecar" files in the same folder with the Raw image file. Displaying the adjusted Raw image consists of re-applying the adjustment steps (stored in the companion file) to the Raw data. The Raw data is never modified.

One can think of the companion file as containing the script to reproduce the final (adjusted) image.

In order to display the adjusted Raw images correctly in the original tool, the adjustment steps (stored in the companion file) have to be available to original tool. Moving/copying only one component (either the original Raw file or its companion) to another folder can break the connection. Hence the request (above) for XnView to associate the Raw file and its companion for purposes of copying/moving/renaming, etc, so that the companion file is always with the image. This is why XnView needs to know which companion file links with which image file.

This concept of a companion file that contains adjustment steps has been extended to include versioning of Raw adjustments (different companion files linked to the same Raw file, but with different adjustments), a very useful thing.

Picasa (and others) picked up on this idea to offer non-destructive editing via the same mechanism. This is why you can sequentially undo adjustments you make in Picasa. The original file (any image file, not just Raw) is never directly modified.

However, the Picasa companion file is a single file that contains sections of adjustment scripts for each image in the folder for which the user has made adjustments. To "companion" a Picasa (picasa.ini) file, an application needs to find the file's adjustment data inside the Picasa file, extract it, then post it to an equivalent in the target directory. Many of us dislike extra files in our folders, but IMHO Picasa's approach to companion files puts an undo burden on 3rd party utilities.

Another approach to companion files (for appropriate formats: jpg, for instance) would be to imbed the adjustment script in the IPTC of the image file. This is an approach that XnView could use if versioning and non-destructive editing ever became a priority...

The industry at large needs a (perhaps XML) standard companion or sidecar file structure which all softwares write to. That would simplify things considerably, allowing, for instance, XnView to apply adjustments similar to Lightroom's adjustments to any Raw images selected by users for viewing purposes.

I seem to have strayed from my original intention (sorry), but maybe these words will help someone.

Fantastic, John, thank you. We now have a new topic in the help file called "Companion Files," which is your text more or less word-for-word. I changed some minor things--contractions and "IMHO" and 3rd and such--but nothing significant. Your writing is excellent, clear, to the point, and very readable--please feel free to contribute on any subject that strikes your fancy. Thanks very much.

Here's what it looks like now, and as it will appear in the help file.

Thanks also from me, John.
Do you know which files count as a "companion" to raw files in XnView at the moment? Only the associated jpg file?
In fact I don't think that it is possible for XnView to identify all possible companion files the different converters create. E.g., from a file called photo.ORF (Olympus Raw Format), Bibble creates a companion called photo.bib, RawTherapee a file called photo.pp2.... That's why I guess it would be a good idea if it was possible to tell XnView which files belong together.
Best wishes
Frank