Compression setting for JPEG XL doesn't work.

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rafc42
Posts: 2
Joined: Thu Nov 04, 2021 7:24 pm

Compression setting for JPEG XL doesn't work.

Post by rafc42 »

I noticed that changing the compression level for JPEG XL format doesn't do anything - it seems stuck at a value of 7.
- changed value is not preserved between program runs
- for different compression values resulted image is always identical and conversion time is always identical, while settings this options to values lower than 7 should significantly speed up the process.

So something is apparanty not working as it should.

Thx
Mariusz
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xnview
Author of XnView
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Joined: Mon Oct 13, 2003 7:31 am
Location: France

Re: Compression setting for JPEG XL doesn't work.

Post by xnview »

rafc42 wrote: Thu Nov 04, 2021 7:45 pm - changed value is not preserved between program runs
:bugconfirmed: Thanks to your detailed description I can reproduce the problem.
- for different compression values resulted image is always identical and conversion time is always identical, while settings this options to values lower than 7 should significantly speed up the process.
Which file do you use?
Pierre.
rafc42
Posts: 2
Joined: Thu Nov 04, 2021 7:24 pm

Re: Compression setting for JPEG XL doesn't work.

Post by rafc42 »

xnview wrote: Wed Nov 10, 2021 12:58 pm
- for different compression values resulted image is always identical and conversion time is always identical, while settings this options to values lower than 7 should significantly speed up the process.
Which file do you use?
It doesn't depend on file.
For example, with this file https://upload.wikimedia.org/wikipedia/ ... -large.png
I got with XnConvert 1.94:
  • quality 80, compression 7 = the size of jxl file of 957671 bytes, conversion time 10s
  • quality 80, compression 2 = the size of jxl file of 957671 bytes, conversion time 10s
Byte by byte comparison shows both files are identical.

When using cjxl v0.6.1:
  • cjxl -q 80 -e 7 = the size of jxl file of 952609 bytes, conversion time 10s
  • cjxl -q 80 -e 2 = the size of jxl file of 1117931bytes, conversion time 3s
cjxl works as expected.
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xnview
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Joined: Mon Oct 13, 2003 7:31 am
Location: France

Re: Compression setting for JPEG XL doesn't work.

Post by xnview »

Right, will be fixed
Pierre.