Why has JPEG format changed in recent versions of Photoshop?

R_Kelly wrote:

 

As an experiment try File>Save for Web>Jpeg and see if the older program reads those.

 

Likely photoshop is adding some metadata that the old program doesn't like.

Most like something that was added to the jpeg specifications, since jpegs from Zoner Photo Studio exhibit the same issue.

Thanks for the suggestion. Unfortunately, it made no difference, even if I set 'metadata' to 'none'.

I think that metadata are unlikely to be the problem, because the files are OK when I add metadata (such as a description) in XnView.

R_Kelly wrote:

 

Can you tell us what the name of the old program is?

Intkey. It's available at http://delta-intkey.com/www/programs.htm. The CSIRO version is the one with the problem; the ALA port is OK (but requires Java).

R_Kelly wrote:

 

According to this photoshop dropped one piece of data from the old JFIF standard to be compliant with the newer EXIF standard starting with photoshop cs5, so maybe that's the problem.

 

https://feedback.photoshop.com/photoshop_family/topics/jpeg_format_different_between_cs2_a nd_cs6?topic-reply-list%5Bsettings%5D%5Bfilter_by%5D=all

Thanks. It looks as though that's the problem.

However, the reasons given for not having an option to write the old format seem spurious. According to Chris Cox at the above page: "you cannot write a JFIF file that is EXIF compatible -- most EXIF compatible readers will choke on it (which is why we got so many complaints about Photoshop continuing to write JFIF)". I haven't found any modern apps that don't read both formats. No doubt there are some, but it would be up to users (the people creating the JPEG files) to decide which format was appropriate for their applications. In my case, the applications are Intkey and related programs, and Web browsers. The latter have no problems with the old format.

So, it seems I'll just have to use the workaround given in my original posting: use another program to do what Photoshop programmers consider impossible (or impractical). Fortunately, there are free programs around that do the job.

Incidentally, the reason I use Zoner is because of its good facilities for editing metadata, and for displaying selected metadata when viewing images ('slideshows'), though I still use Photoshop for editing the actual image content. In particular, I like to add descriptions (captions) and GPS data to my personal photos. As a result of investigating this problem, I stumbled across XnView, which is free, and has better facilities than the current Zoner for displaying captions in slideshows. If anyone is interested, there are some examples at http://www.dpreview.com/forums/thread/3478699#forum-post-51416126 - I suggest using the 'flat' view of the forum.

Thanks again for your help.

Stephen_A_Marsh wrote:

 

Mike can you please provide a link to a “good” file and a “bad” file via DropBox or similar file sharing sites, FTP etc?

The following files are in http://delta-intkey.com/test\jpeg01.zip.

JPEG files tested in CSIRO Intkey

CS6.jpg - created in Photoshop CS6. Can't be read by Intkey.

The following files were converted from CS6.jpg by various programs. All can be read by Intkey.

CS6-CS4.jpg - Photoshop CS4

CS6-NConvert.jpg - NConvert (command-line image converter, http://www.xnview.com/en/nconvert/)

CS6-Paint.jpg - Paint (image editor included in Windows 10)

CS6-XnView.jpg - XnView (multimedia viewer, organizer and converter, http://www.xnview.com/en/)

CS6_JFIF_Added.jpg worked. CS6_Rebuild.jpg didn't.