Add additional image formats for photo upload?

Is there a way to add additional image formats to the photo upload function? Current formats seem limited to .gif, .png, .jpg or .jpeg.

By photo function do you mean CB Gallery? Yes, but they'll be treated as Files and not Photos so you'll need to add your other extensions under the Files media parameters. What extensions are you trying to use?

Some time ago Apple made the default photo image format .heic

Many of our members are iPhone users and are not able to upload the photos from their devices.

They get the error: Invalid file extension. Please upload only jpg, jpeg, gif, png!

We try to explain the very complicated procedure of changing the format of the photo before uploading, but it is too difficult for many so we receive complaints about our website functionality.

This is in CB Gallery but also when trying to upload avatar photos.

Some time ago Apple made the default photo image format .heic

.heic is not a HTML supported extension. It will not render in browsers. Not even in Apples own Safari. Will review adding support for converting .heic to a browser safe extension server side for a future release. This will not be possible client side so you will lose client side resizing for that conversion which will be a lot slower to upload unfortunately. Only way to convert that format client side is to use a massive 1MB JS library to do it and that's not going to happen.