Add support for DNG 1.7

[qdwang]

DNG 1.7 supports JPEG XL content which is very useful for dng compression.

I can provide two samples here:

samples.zip

One is in Bayer pattern, the other is in linearRGB pattern.
Both of them can be correctly opened by Lightroom latest version and MacOS Preview.

If you guys need more samples, I created a website TinyDNG which can compress any DNG files to a JPEG XL compressed DNG.

[kmilos]

Please upload any samples directly to https://raw.pixls.us/

This is already tracked by darktable-org/rawspeed#516, so please feel free to continue any discussion there.

See also #16618

[qdwang]

Please upload any samples directly to https://raw.pixls.us/

This is already tracked by darktable-org/rawspeed#516, so please feel free to continue any discussion there.

See also #16618

I'd like to upload the samples to raw.pixls.us, but it's down for 3 days...

[kmilos]

I'd like to upload the samples to raw.pixls.us, but it's down for 3 days...

@LebedevRI

[LebedevRI]

I'd like to upload the samples to raw.pixls.us, but it's down for 3 days...

@LebedevRI

@andabata

[andabata]

Server had an unrecoverable crash, lost loads of data, will take time to get it all sorted it again.

…

On Tue, Jul 16, 2024 at 08:51:13AM -0700, Roman Lebedev wrote: > > I'd like to upload the samples to raw.pixls.us, but it's down for 3 days... > > @LebedevRI @andabata -- Reply to this email directly or view it on GitHub: #17152 (comment) You are receiving this because you were mentioned. Message ID: ***@***.***>

[LebedevRI]

Server had an unrecoverable crash, lost loads of data, will take time to get it all sorted it again.
…
On Tue, Jul 16, 2024 at 08:51:13AM -0700, Roman Lebedev wrote: > > I'd like to upload the samples to raw.pixls.us, but it's down for 3 days... > > @LebedevRI @andabata -- Reply to this email directly or view it on GitHub: #17152 (comment) You are receiving this because you were mentioned. Message ID: @.***>

Oh well.
Thank you for all your work!

[golemusu]

+10.

I have already converted my whole RAW collection to DNG 1.7 lossy (with Adobe DNG converter) as it reduces space consumption by 50-60% (or even 80% if it is uncompressed DNG like in Galaxy S21fe). In couple of A/B tests I did with Adobe Lightroom I could not see a difference between lossless DNG and much smaller lossy DNG.

So now I have from each pic a lossless DNG (typically 10-12MB as it is 12mpx) and lossy DNG 1.7 (typically 4-5MB). I will delete all lossless versions and gain about 50GB of HD space but will have to wait until Darktable and couple of other programs have DNG 1.7 support.

If you are professional photographer with much larger collection you can probably save hundreds or even thousands of GB of space by converting "not so important" pics to DNG lossy! And I am already replying in advance for potential "storage is cheap comments", it is actually not that cheap if you have your stuff in cloud. And being able to send the files more than 50% faster is also very appealing.

There is also another very good feature with DNG 1.7, when you convert with Adobe DNG converter to DNG 1.7 lossy you can also reduce resolution. So if you have huge 50mpx or larger RAW pics you can reduce space consumption by up to 95% ! if you drop the resolution also to 10-12mpx which is probably good enough for 95% of applications.

I read from LibRaw changelog that DNG 1.7 support (with JXL comp) should already be in LibRaw so is there any plans of bringing this to DarkTable?

[kmilos]

I read from LibRaw changelog that DNG 1.7 support (with JXL comp) should already be in LibRaw so is there any plans of bringing this to DarkTable?

No, because LibRaw would have to be built w/ Adobe DNG SDK:

"DNG 1.7 (including JPEG-XL compression) support via Adobe DNG SDK 1.7.x integration"

As this issue is a closed duplicate, please continue any discussion at darktable-org/rawspeed#516

There is also darktable-org/rawspeed#755 for testing.