How to filter photos based on brightness or histogram

[LukeFarrer]

We have a lot of photos of outdoor scenes that are very similar. Some point towards the sky and are consequently much brighter. Others point towards the ground and consequently do not contain sky and are on average much darker.

We need a way to auto select in Develop mode all the pictures that are brighter (above a certain brightness threshold). Is there a quick way to do this? Or would we need to write a script that examines the histogram or something like that?

Currently we are doing this process manually and it is very time consuming.

Any suggestions would be hugely appreciated. Thanks.

Luke

[JohanElzenga]

I don't think there is any way to do this. Not using the default options in Lightroom Classic and not in any plugin I know.

[Jao vdL]

You would need to write some sort of plugin or external program that evaluates previews or even the raw images themselves based on a criterium like this. Wouldn't be that difficult (but definitely not fast) but I don't think anybody has done anything even remotely similar.

[johnrellis]

To build on Jao's reply, a plugin could export the select photos at a reasonable reduced resolution (e.g. 1440 pixels long edge) and then use the open-source Image Magick utility to analyze brightness and many other image characteristics.  

While "straightforward" for an experienced developer, if you don't know the Lua programming language and haven't written LR plugins, it could easily take many tens of hours to get something simple implemented. 

[LukeFarrer]

Thank you for your useful reply. I think analysing the images using ImageMagick would be a good starting point.