Topic: Deleted EXIF data in JSON files?

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WanderingArtist (Over 1 year ago)
Is there a way to extract the original image name when exporting the synth data? Specifically, are the original image names in the JSON file? 

I'm working on a photogrammetry process that requires accurate pairing of images to cameras. Currently, when images are uploaded, Photosynth can reorder the images, when compared to the original selection and upload order for the local Photosynth client. 

If anyone knows how to extract the original image names from Photosynth, Please let me know!

And, if it's not possible, then consider this a feature request.
NateLawrence (Over 1 year ago)
Hi, WanderingArtist, 

To my knowledge, the original filenames are not present in the JSON data, however this is more an observation from watching what others have done, rather than extensive first hand investigation.

Several things come to my mind: 

1: According to Photosynth's architect, the images are always sorted lexicographically:

2: I believe that Photosynth's log files contain the filename to image-number-within-the-synth correspondence. This will only help you for your own synths, as compared to the synths of others (since you have access to your own log files, but not others'). I assume you already know how to access your log files, but for others' benefit, open a 'Run' command in Windows (or a 'My Computer|Windows Explorer address bar) and type the following: 
%temp%\photosynther to open Photosynth's working folder.
NateLawrence (Over 1 year ago)
3: You may be interested to know that the thumb.jpg file for each image contains the full original EXIF data for each image, whereas it is deleted from the image tiles for the different resolutions are all stripped of metadata for size reasons.
Henri Astre's PhotosynthTileDownloader included in his PhotosynthToolkit ( ) gives you the option of downloading the thumbs in Step 1 and then automatically writes the metadata from them to the full resolution images in Step 5 after they are downloaded and recompiled.

4: If all the images in the synth have accurate timestamps, you could sort both the originals and the downloaded copies by time in order to have an accurate pairing.

I may have been thinking of other things, but they're not coming to mind presently. I second your feature request, though.
WanderingArtist (Over 1 year ago)
Hey Nate,

I just looked through the log file at the location you specified. I did not know about this log location. Thank you for directing my attention to it.

The ordering of images in the log file unfortunately correlates to no other ordering of images I've seen Photosynth perform. So, I'll be looking through Astre's thumbnail downloader.

Thank you for your attention to this. This is the last problem is an otherwise working and easy photogrammetry solution.