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.

EDIT: The metadata.cfg file is no longer needed; instead the UI has appropriate widgets for all the params, and the file will be generated automatically.

Now the only required setting on fresh install on most distros should be to choose the ultrahdr_app executable.