Category system unstable under one system using Ubuntu at least

[mkc73]

I have just spent a week using categories with about a 1000 images and 50 odd categories which I have been using to meticulously store information about the images - only to find when I started using the categories in anger that around 30% of the information has disappeared. Presumably something to do with the xnview database getting out of sync with the XMP data stored in the files if the system is struggling to cope, who knows. Anyway, some of the XMP data is not in the files anymore. I started out double checking that the data was being stored and gained misplaced confidence that the software was working as intended. The system of writing the XMP data in the background when the image file is deselected appears unreliable and storing the category information in both the xnview database and the XMP data in the file seems a possible place of contention.

Its a pity, because the category management system offers a great way to work with images, when it works.

A trivial example, but one which lost me an hour initially :
I believe data should stay with the image so have export XMP enabled.
I have a set of images with information stored in the file name, let's say image size : Big, Medium, Small, which I want to move to categories so that I can search for particular sized images. So : Select group of BIG images, set category BIG, select first image, rename file because info no longer needed, move to next image and rename etc. Which works fine unless group has only one image when XMP category information is not exported because file is renamed before deselecting.

The more insidious case, which I am still trying to get to grips with :
Select image, adjust category, deselect image, select image -but find category not updated in XMP data in image but is set in xnview catalog.
Try a different image with the same tag get same problem.
Try a different tag from elsewhere in the hierarchical subject tree on the same image works fine.
Seems to be a problem with all tags in that hierarchical subject. Hierarchical subject is not written to XMP lr either.
Quit xnview, restart, select same image, tag assigned in catalog but not in XMP data as left it, deassign tag, reassign tag, deselect, reselect : tag now written to XMP data fine.

Select file with discrepancy between assigned value and XMP data in file, select view/update catalog from files : discrepancy still there.
Select view/update files from catalog : assigned values and XMP data both change.


Perhaps operating system is not behaving itself with regard to saving XMP data to file but xnview is not giving any warning that something is not working correctly.

[xnview]

do you have a way to reproduce the problem each time?

[mkc73]

That would be nice - at the moment I am just working for a while when I notice that a problem has occurred. The only lead I have is that maybe worth investigating if moving categories in the category pane by mistake is implicated.

[xnview]

That would be nice - at the moment I am just working for a while when I notice that a problem has occurred. The only lead I have is that maybe worth investigating if moving categories in the category pane by mistake is implicated.

if you could find a pattern to reproduce?

[mkc73]

Hi Pierre,

I am trying to keep track but not obvious what causes my problem yet. The problem was exacerbated because I am using the files as the repository of the tag information and was happy to delete the catalog every now and then as I was exploring categories and catalog etc. I think the catalog was always valid but xnview would occasionally get into a state where the XMP data was not being exported on deselection of images - so when I deleted the catalog I lost all the information I had generated. I am now checking XMP data for each image after deselection.

[mkc73]

With export XMP data enabled, I was deleting and renaming images within xnview; deleting, adding, renaming categories with xnview; deleting catalog; importing categories from file. all without much attention as to whether some images existed with those category tags. I am now a bit more careful.

[mkc73]

Still having problems with this despite being careful to only move/delete categories with no entries. I am coping with it by explicitly checking that the XMP data has the same keywords as the assigned values from the database after each change to the keywords. Every so often (somehow associated with adding/moving categories in the category pane I find that the assigned values have not been written out to the XMP data. No amount of deassigning/reassigning keywords fixes it. Closing xnview and reopening xnview still leaves the discrepancy but now deassigning/reassigning a keyword writes the keywords out to the XMP data correctly.

That's irritating but still usable.

However, today had a case where closing and reopening xnview left the correct keywords in assigned but deasigniing/reassigning a keyword actually removed some keywords from the XMP data. Closer inspection showed that the category pane did not have some of the keywords that had been assigned.
Clicking on a lot of folders with images recovered the keywords in the category pane and then deassigning/reassigning wrote out the keywords to the XMP data correctly.

What is the interaction between the catalog (ie the assigned values) and the category pane ? How is it possible that keywords that show as assigned when selecting an image do not appear in the category pane at all. When the keywords are written out to the XMP data only those selected in the category pane seem to be written?

[xnview]

However, today had a case where closing and reopening xnview left the correct keywords in assigned but deasigniing/reassigning a keyword actually removed some keywords from the XMP data. Closer inspection showed that the category pane did not have some of the keywords that had been assigned.
Clicking on a lot of folders with images recovered the keywords in the category pane and then deassigning/reassigning wrote out the keywords to the XMP data correctly.

What is the interaction between the catalog (ie the assigned values) and the category pane ? How is it possible that keywords that show as assigned when selecting an image do not appear in the category pane at all. When the keywords are written out to the XMP data only those selected in the category pane seem to be written?

Do you have a way, and some files to reproduce the problem?
Whan you assign a category, catalog (database) is updated, and following the settings embedded or sidecar metadata

[mkc73]

Do you have a way, and some files to reproduce the problem? Associated with messing around with categories in the category pane but to date have not been able to find a particular set of operations which produce the problem - even though checking the XMP data are each change spots the problem immediately after it occurs??

Whan you assign a category, catalog (database) is updated, and following the settings embedded or sidecar metadata

SO the catalog is succesfully updated but the XMP embedded settings are not updated (I am not using sidecar metadata).
Where is the list of settings in the category pane garnered from?

[xnview]

Where is the list of settings in the category pane garnered from?

?

[mkc73]

Just trying to understand how the category pane can be missing categories that appear as assigned - though this is not something I have seen again yet.

[xnview]

Just trying to understand how the category pane can be missing categories that appear as assigned - though this is not something I have seen again yet.

Yes strange. you work with jpeg files?

[mkc73]

Yes - mostly Jpeg or png. I have occasionally found that I am categorizing a webp file though which is a potential problem : the catalog is updated with my categorization but no XMP is written out so if I were to delete the catalog (which I was doing previously) the categorization would be lost. There is nothing to warn me that the XMP data cannot be written out. This is not the source of my main problem though, which is that after messing about with categories in the category pane a mismatch occurs between what is in the catalog and what is written out to the XMP data. Typically I count the number of categories which have been 'assigned' and then check the number in the XMP data and find one less in the XMP data which prompts closing and restarting xnview.

[mkc73]

It would be very helpful if that could be done in xnview ie if xmp output selected check after writing that no of xmp lr items is same as assigned and issue warning ?

[xnview]

It would be very helpful if that could be done in xnview ie if xmp output selected check after writing that no of xmp lr items is same as assigned and issue warning ?

You have not found a way to reproduce easily?