Exporting from Preview, JPG vs JPEG creates corrupt Windows files

clarkysdonga wrote:

BUT, if i select more than one image and export them they are all .jpeg which doesn't open on a Windows machine (Sorry, Photos can't open this file because the format is currently unsupported, or the file is corrupted).

You might have stumbled on an old Preview bug when exporting many images as another codec:

1. Open many images (.heic, for example) in Preview.app.

2. Edit > Select All.

3. File > Export Selected Images... > Show Options > Select some other Format (JPEG, for example).

Result: All files have .jpeg suffix and the very 1st exported file(s) might really be .jpeg but the rest are really .heic (HEIF) if you inspect them with Preview > Tools > Show Inspector > General Info.

Older versions of macOS used to export just .jpg from Preview, but in the last few releases of macOS, this has changed to .jpeg. Since no Apple-badged employees participate here, there will be no official explanation for this format name change. It may simply be one Apple developer's whim and no one caught it.

It is not limited to Preview, as I have a Shortcut that splits PDF pages into .jpeg images. This has been the case with Ventura, Sonoma, and Sequoia.

I forgot to mention, .jpgs & jpegs are identical formats. The reason Microsoft chose .jpg originally was because DOS only supported three character extensions. That time has long since past.

clarkysdonga wrote:

Why would Apple change the extension from .jpg to .jpeg for a batch export?

We have no idea why. But they did. You can easily change the extension from jpeg to jpg with Name Mangler . It's a very powerful renaming app.

You can also quickly convert the heic files to jpeg files with the HEIC Converter app from the App Store. Just drop a folder of heic images on the app and it's done.

clarkysdonga wrote:

Im having an issue where if i select a single .HEIC image and export if from Preview I get a file with the extension.jpg which opens fine on a Windows machine. BUT, if i select more than one image and export them they are all .jpeg which doesn't open on a Windows machine (Sorry, Photos can't open this file because the format is currently unsupported, or the file is corrupted).

Why would Apple change the extension from .jpg to .jpeg for a batch export?

I doubt it, but you’d have to ask them.

You can change it. Not sure why Windows would have a problem with a standard file extension.

clarkysdonga wrote:

BUT, if i select more than one image and export them they are all .jpeg which doesn't open on a Windows machine (Sorry, Photos can't open this file because the format is currently unsupported, or the file is corrupted).

They must have been corrupted somehow. I batch exported a dozen images from Preview to an ExFAT formatted flash drive as .jpegs, plugged the drive into my Asus Windows laptop and it had no problem opening all of them.

Why would Apple change the extension from .jpg to .jpeg for a batch export?

Did it change the .heic extension to .jpeg?

clarkysdonga wrote:

Why would Apple change the extension from .jpg to .jpeg for a batch export?

It's just a bug. There are a few oddball places that use a ".jpeg" extension. The bulk export is just one of those.

After exporting, you can select all of the images in the Finder, control-click or right-click on them, and choose "Rename". Use the "replace text" option and replace "jpeg" with "jpg".

Normally, Finder will complain if you try to change a file extension like this. But in this case, it seems to know that "jpeg" and "jpg" are the same, so it just does it.

Apparently I wasn't opening enough .heic files. When I batch exported 4 .heic files they were all fine. But when I batched exported 14 .heic files, the first 4 were fine, the rest were still .heic files, despite the .jpeg extension.

clarkysdonga wrote:

Will keep everyone updated. They need to fix this asap.

LOL! The sun will burn out before Apple fixes a bug like this. Just rename the files. Takes 3 seconds.

If this is something you do 15 times every day, maybe convert them using the "sips" command line tool.

sips -s format jpeg -o new  *.heic

where "new" is a directory

dialabrain wrote:

Personally I prefer the free XnConvert app which for some reason is no longer in the App Store since I posted two hours ago. lol

https://www.xnview.com/en/xnconvert/

It's still in the Canadian store. And it is free - no in-app purchases or anything.

Or in the Zsh shell when in the same folder location as the .jpeg images:

autoload -U zmv
zmv '(*).jpeg' '$1.jpg'



FWIW, XnConvert in the App Store will correctly batch convert the .heic files.

Personally I prefer the free XnConvert app which for some reason is no longer in the App Store since I posted two hours ago. lol

https://www.xnview.com/en/xnconvert/

And it's back! wth? lol