P: JPEG XL support

With the release of Photoshop 2026, I still find jpegxl support extremely poor. 

All apps I use can save JpegXL (10K res) at around 100MB, but Photoshop manages 1Gb. 10x the amount. 

It still cannot do 16bit

Even going down to 8 bit the sizes are widly different to the other programs that can save jpegxl

I'm glad that my skepticism was proven wrong and that this shipped in 26.8.

However after a couple of months using it, I've noticed a quality issue in Lossy mode:  compression artefacts at Quality 100 are much more significant than one would expect.

It's as though Quality 100 in Photoshop is like Quality 90 in the JPEG XL reference implementation and it's not possible to get higher quality output from Photoshop without switching to Lossless mode.  It looks like the target distance for Quality 100 in Photoshop needs to be tuned a bit lower.

Here's a zoomed in comparison that demonstrates the difference:

(to be clear, the CJXL version is not transcoding)

File size comparison:

Photoshop Lossy Quality 100: 140 KB

CJXL Lossy Quality 90: 133 KB

CJXL Lossy Quality 99: 343 KB

(and of course Lossless mode from Photoshop and CJXL is larger - about 515 KB for both)

Since CJXL with Quality 90 has about the same file size and compression artefacts as Photoshop at Quality 100, this to me suggests that the target quality distance that Photoshop is using for Quality 100 is set quite a bit higher than the reference implementation.

Can we get this tweaked so that Quality 100 in Photoshop allows higher output quality at the expense of a larger file so we have more range to work with before having to switch to Lossless?

@jimmy_4380 

I have a WebP batch converter script here:

https://community.adobe.com/t5/photoshop-ecosystem-discussions/export-many-files-at-once-in-webp-format-photoshop/td-p/13604411/page/4#U14859793

The latest August update is working well. Next on the list is adding layers support...

I still note some gamma issues, LR will display a 16 bit image ok but the gamma is different in PS, but I can live with that

going from 32 bit down to 16bit no longer makes a black image

@drewdawg 

Two things:

First, you're not comparing at 100% view. The screenshots are not the same scale, so screen resampling enters the equation. 100% means that one image pixel is represented by exactly one physical screen pixel. You have to view at 100% for any reliable assessment of pixel structure (sharpness/grain/artifacts).

Second, there is never a color shift by saving a file. The RGB numbers are saved as they are and are not changed. What changes color is profile/color management inconsistencies - specifically, a missing profile, or an application that doesn't support color management. Without an embedded profile, the numbers are randomly interpreted according to each application's default policies. Always make sure the file has an embedded profile, and that the application honors that embedded profile. Photoshop will do that by default as long as there is an embedded profile.  

Thank you so much for taking the time for your constructive comments.

I just used Mac Preview for covenience to show the two images in a reasoble size. Laziness.. But the artifacts are still there in the images no matter how you look at them.

I used Photoshop for the conversion. The CJXL command line program does not produce the same artifacts. I think you are right -- it is the color profile which is set to Adobe instead of sRGB. But what a pain to convert them all prior.

Hi Drewdawg,

your second post compares png to jxl, your third post compares dng (16bit) -Photoshp Beta to jxl (Apple Preview?)

Not saying you are wrong to be concerned, just wanting to check that you have eliminated Color shift due to something else, eg ICC profile behaviour with the different Apps, Adobe Photoshop (Beta particularly) has a nasty habit of resetting Colour Settings and CM Policies when it upgrades, and often Photoshop and Preview will display differently. I wasn't even aware you could open a .dng directly in Photoshop (maybe its only on Save that the filename changes) but the interim Camera Raw opening step sets the ICC based on the ACR Workflow Settings.

Also the jxl Export from Lightroom (last time I checked) is still producing artifacts with some ICCs.

Notice the substantial increase in pixelization from the original .DNG file to .JXL with the Adobe encoder. This is Lossy setting but max quality. Note the pearl and eyes. Note the slight color banding in skin of the forehead. 

There is a substantial red shift on Adobe's implementation of Lossless JXL.

Consider:

In the center is the original PNG file (15 MB RGB 16 bit coverted from a .dng file).

To the left is output from one of the reference JXL implementations is C. Bit by bit and color wise indestiguishable -- even at the pixel level.

To the right is Adobe's Lossless JXL. The overall tone has shift red with an appearnt sharpening step that I did not apply.

It was added but still pretty buggy...

o Lossless JXL files come out 2,3x LARGER than the source .NEF files used as input;

o Often a 0 byte output without explanation;

o Previous beta version had patchy and intermittent color shifts so inspect your output carefully.

When it works, it is glorious. Better compression than Apple's HEIC and theoretically huge image support. For whatever reason, Adobe has struggled to release a solid version of it however.