Added UltraHDR export plugin to generate UltraHDR JPEG images.

[koto]

No description provided.

[wpferguson]

I/m not sure how to use this. I read the header comment and it says I need to provide a jpg image and a gainmap image. I read the ultrahdr_app documentation and it says I need to supply an SDR image and an HDR image.

Could you please provide a workflow that I can use to test this?

Thanks

[koto]

I/m not sure how to use this. I read the header comment and it says I need to provide a jpg image and a gainmap image. I read the ultrahdr_app documentation and it says I need to supply an SDR image and an HDR image.

The script is using the API-4 encoding variant, i.e. one that expects a JPEG SDR and a JPEG gainmap on input, both of which can be created quite easily in darktable. In hindsight, I probably should make this clear in the UI as well.

Could you please provide a workflow that I can use to test this?

https://discuss.pixls.us/t/manual-creation-of-ultrahdr-images/45004/12

[koto]

I added a combobox in UI for choosing the encoding variant, so that user knows what the required inputs are. Adding new encoding variants in the future (e.g. SDR and HRD -> UltraHDR) will now be easier.

[koto]

I changed the plugin to appear as a lib (prevously it was an export storage plugin), cleaning up the UI, adding more descriptions, tooltips, and exposing preferences. I also added support for generating UltraHDR images from SDR + JPEG-XML HDR image pairs.

https://www.youtube.com/watch?v=q5hrx2E7BL4 demonstrates generating UltraHDR JPEGs from SDR + monochrome gainmap pairs.

The biggest challenge for plugin users is that is requires compiling ultrahdr_app from libultrahdr, but I suspect this might eventually change when the library makes it to package managers. Other required binaries (ffmpeg, exiftool) are trivial to obtain.

@wpferguson, LMK if this passes the bar for lua-scripts contrib. If not, I might release it in a separate repo for my own use case.

[wpferguson]

I'm trying to run this in a completely new environment. I have an SDR raw and I duplicated it and created a gainmap. I select option 1 (SDR + Gainmap) and use original location. I hit the button to run it and it crashes in option 2.

    79.5329 LUA INFO: callback: using encoding variant 1 
    79.5646 LUA ERROR : ...ll/.config/dttest502_ultrahdr/lua/lib/dtutils/string.lua:305: bad argument #1 to 'match' (string expected, got nil)
stack traceback:
	[C]: in ?
	[C]: in function 'string.match'
	...ll/.config/dttest502_ultrahdr/lua/lib/dtutils/string.lua:305: in upvalue '_should_be_sanitized'
	...ll/.config/dttest502_ultrahdr/lua/lib/dtutils/string.lua:316: in function 'lib/dtutils.string.sanitize'
	(...tail calls...)
	...bill/.config/dttest502_ultrahdr/lua/lib/dtutils/file.lua:459: in function 'lib/dtutils.file.check_if_file_exists'
	...bill/.config/dttest502_ultrahdr/lua/contrib/ultrahdr.lua:150: in upvalue 'assert_settings_correct'
	...bill/.config/dttest502_ultrahdr/lua/contrib/ultrahdr.lua:352: in function <...bill/.config/dttest502_ultrahdr/lua/contrib/ultrahdr.lua:343>
	[C]: in ?

I hovered all the widgets looking for tooltips to tell me what is wrong or what I'm missing, but I didn't get enough information to figure it out.

[koto]

I fixed the crash, thanks! And many other errors that are obvious when running the plugin on a clean profile 😅

When generating UltraHDRs with gainmaps as inputs, the metadata.cfg file is also required. Previously you had to select one from libultrahdr/examples directory, but now I added the option of just generating it, which will happen on first run. Now the only required setting on fresh install on most distros should be to choose the ultrahdr_app executable.