ExifTool Forum

General => Metadata => Topic started by: c++ on May 04, 2023, 08:10:51 AM

Title: Data for Phil
Post by: c++ on May 04, 2023, 08:10:51 AM
Hi Phil,

regarding https://exiftool.org/sample_images.html
You'll find several you might want in the enclosed.

For each of 'em I took one of your tiny JPEGs from the existing archive and essentially did:
exiftool -all= -tagsFromFile my_original.jpg -overwrite_original tiny_target.jpg

All of these are production models, no weird beta cameras.
Title: Re: Data for Phil
Post by: StarGeek on May 04, 2023, 11:04:46 AM
Unfortunately, the command you used does not result in a new file with the original data. Tag locations can be changed unless explicitly corrected for (see FAQ #9 (https://exiftool.org/faq.html#Q9)).  And even if you do use -All:All, exiftool will not copy any obscure tags that it doesn't know about.

And even after that, exiftool can change the structure and order of the metadata when writing (see FAQ #13 (https://exiftool.org/faq.html#Q13)).

When creating the test images he's almost certainly using a custom script to make an exact copy.

The best solution would be to email a sample file or DM him with a link. 
Title: Re: Data for Phil
Post by: Phil Harvey on May 04, 2023, 12:17:31 PM
Yes, I'll need original images for the collection.  I have a special script that swaps the image and preserves the original metadata structure for the samples page.

- Phil
Title: Re: Data for Phil
Post by: c++ on May 04, 2023, 04:35:00 PM
Quote from: Phil Harvey on May 04, 2023, 12:17:31 PMYes, I'll need original images for the collection.  I have a special script that swaps the image and preserves the original metadata structure for the samples page.
Too bad, thought I could help you with this. Intersted in sharing said script? If not it's a no go the image data these come from does not leave here :-) Maybe I have a second set of images I'm willing to share. If so I'll send them by wetransfer one day.
Title: Re: Data for Phil
Post by: Phil Harvey on May 04, 2023, 08:26:57 PM
Here is a post (https://exiftool.org/forum/index.php?topic=1846.msg8031#msg8031) where I give the script that I use.

You need to run it in a folder that contains t/images/Writer.jpg because it uses this as the source image.

- Phil
Title: Re: Data for Phil
Post by: c++ on May 04, 2023, 10:16:22 PM
This is the first bunch using said script.
Title: Re: Data for Phil
Post by: c++ on May 04, 2023, 10:17:47 PM
And the rest of the lot. Obviously you were right these are way bigger now.
Title: Re: Data for Phil
Post by: c++ on May 04, 2023, 10:22:09 PM
since I made a windows executable of the script, now using a ./writer.jpg in the same dir as the *.exe. I figured I might as well share that here, too.
Title: Re: Data for Phil
Post by: c++ on May 05, 2023, 07:54:18 AM
Images from newer cams are ~600kb rather than ~12 like the rest, and appear to contain a pretty large thumbnail of some kind. I don't see this on the exiftool samples of the same cameras (some are on the list in the archive already). How do I remove said thumbnail or is it fine?

Well, these are from the secondary set I mentioned and thusI don't mind this too much but the likes of
dd if=Canon\ PowerShot\ N.jpg of=n-test.jpg bs=1 skip=19730sure give me a small jpeg...
Title: Re: Data for Phil
Post by: Phil Harvey on May 05, 2023, 11:58:03 AM
Quote from: c++ on May 05, 2023, 07:54:18 AMImages from newer cams are ~600kb rather than ~12 like the rest, and appear to contain a pretty large thumbnail of some kind. I don't see this on the exiftool samples of the same cameras (some are on the list in the archive already).

Can you give me a specific model name and I'll take a look?

- Phil
Title: Re: Data for Phil
Post by: Phil Harvey on May 05, 2023, 12:22:21 PM
Out of all those files, there were only 2 new ones:

    CanonDIGITAL_IXUSi_Zoom.jpg
    CanonIXUS175.jpg

- Phil
Title: Re: Data for Phil
Post by: c++ on May 05, 2023, 08:01:23 PM
Do update the CanonPowerShotA800 as well yours is some weird FW version of a camera. Same holds true for CanonPowerShotS110-new CanonPowerShotN100 CanonPowerShotG9 but I have neither of those three. Actually for uses like feature testing the CHDK camera select routines that work by FW revision different FWs of the cameras would be worthwhile but I did not look into how to quickly rename the files based on that. So up to you whether you would like to keep different versions.

Quote from: Phil Harvey on May 05, 2023, 11:58:03 AMCan you give me a specific model name and I'll take a look?
Nice, let's take the Powershot N I mentioned, I'll give you the full image also. And the stripped down one that kept the thumbnail I spoke of. Would still be nice to get this fully working, so perhaps I'll just make the different FW meta data collection myself one day, don't have all cameras though just maybe 150.
Title: Re: Data for Phil
Post by: c++ on June 18, 2023, 04:24:37 PM
It would still be nice to know how to remove that thumbnail while keeping the exifdata extracted stay accurate. It's not urgent but would be nice to know.