Lossless jpeg xl images not rendering correctly in Preview on macOS 15.7

Heh! No, not that. The dark pixels along the edge of the .jxl image. They aren't on the PNG version.

Not quite as pronounced here, but the same issue as this.

I can't test to see if Graphic Converter is doing that when saving a PNG out to a JPEG XL image.

There may be an app that does a better job of conversion from .png to .jxl but I'm not going to install every graphic app to test. :)

I have Pixelmator Pro and it doesn't even have the option to create .jxl files.

There may be an app that does a better job of conversion from .png to .jxl but I'm not going to install every graphic app to test. :)

Ugh! That would take a loooooong time. And some you can't test at all without purchasing them.

Up until grabbing Graphic Converter and Acorn for testing, I'd been doing all of my testing in Photoshop. Nothing I do in PS causes an edge like that when saving to a JPEG XL.

My very first thought when I saw this topic was, "Oh, goody. Just what the world needs. Yet another image format."

Does JPEG XL save space? Yes, but not enough to make anyone jump up and down in rapturous glee. Using lossless, it's slightly better than PNG. But nowhere near enough to make me think about running thousands of stored images through an automated Photoshop action to convert them from TIFF with LZW lossless compression to JPEG XL lossless.

etresoft wrote:

I'm afraid that Preview is singularly unsuitable for anything like that. It's right there in the name - "Preview". Apple sure didn't name it "Colorspace Reference Tool" now did they?

+1

I was going to say the same general thing. Preview is good enough for taking a quick look at something, but can't be trusted for anything resembling accuracy.

Per your note that Apple routinely fixes one thing, then breaks three other things, a few years back Preview couldn't display a CMYK image. The image would show as solid black. Nothing wrong with the images, just Preview being Preview.

Not sure what you're seeing but I downloaded the jpeg xl image from this page: https://jpegxl.info/resources/jpeg-xl-test-page.html, and it seems fine in Preview.

Well, they are fine on my iMac Pro running Sequoia 15.7.

I can't see a difference. Top image is a .jxl file lossless. Bottom is the original .png. Open the image in a new tab for full size 4480x2520.

If I remember reading it correctly, newer iPhones use jpeg xl as the default for jpegs.

tangyminty wrote:

I have created a number of jpeg xl saved images to reduce storage space.

You didn't mention what you used to create them in the first place.

FWIW, the top left image is from Graphic Convertor 11, not Preview. GC 11 is seriously out of date. The current version is 12.4.2.

The screenshot in my previous post I created in Tahoe, this one in Sequoia 15.7 so you didn't think I was pulling some sort of shenanigans. Again, they look identical…

Just to add, I don't see that GC12 has a JPEG XL option. It does have a JPEG Lossless option, but there's no indication it is .jxl.

You have to click Show All at the bottom of the image option types to get to JPEG XL (and about 50 more 🙂).

After you've used it once, it remains as a choice in the short list.