Luminous Landscape Forum
Raw & Post Processing, Printing => Adobe Lightroom Q&A => Topic started by: PeterAit on August 08, 2025, 09:14:57 am
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I know that LR can easily find images that have been converted to B&W in the develop module. But I want to find all images monochrome such as scans of old prints or photos converted to B&W in another app. Can this be done?
Thx
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I can't imagine how Lightroom would be able to do this unless there were metadata in the image files or distinguishing features in the filenames that could be used to determine which were monochrome. Probably the best bet would be to add a keyword to each monochrome image, then use a smart collection as a repository. Prospectively, that could be done at the time of import of a scan or monochrome capture, or conversion of a color original — and retrospectively by locating all the monochrome images visually and adding the keyword to them.
For an automated approach, it would be necessary to create a software application that was able to recurse its way through a hierarchy of image files and detect monochrome instances from innate characteristics of the files themselves; this would presumably require different tests for rendered and raw files. But building a robust tool would involve some heavy lifting and there still would be a secondary issue of how to flag the monochrome images so Lightroom could find them. Preferably without modifying the files themselves. Maybe a Lightroom plug-in?
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No, it can't be done automatically. But keywords would go a long way towards doing this in the future.
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I can't imagine how Lightroom would be able to do this unless there were metadata in the image files or distinguishing features in the filenames that could be used to determine which were monochrome. Probably the best bet would be to add a keyword to each monochrome image, then use a smart collection as a repository. Prospectively, that could be done at the time of import of a scan or monochrome capture, or conversion of a color original — and retrospectively by locating all the monochrome images visually and adding the keyword to them.
For an automated approach, it would be necessary to create a software application that was able to recurse its way through a hierarchy of image files and detect monochrome instances from innate characteristics of the files themselves; this would presumably require different tests for rendered and raw files. But building a robust tool would involve some heavy lifting and there still would be a secondary issue of how to flag the monochrome images so Lightroom could find them. Preferably without modifying the files themselves. Maybe a Lightroom plug-in?
My notion was for the program to look at an image's color histogram. If the R, G, and B curves overlap perfectly then the image is monochrome. There could be an adjustable tolerance so that "almost mono" images would be tagged. For example, a scan of a sepia-toned print.
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My notion was for the program to look at an image's color histogram. If the R, G, and B curves overlap perfectly then the image is monochrome. There could be an adjustable tolerance so that "almost mono" images would be tagged. For example, a scan of a sepia-toned print.
https://community.adobe.com/t5/photoshop-ecosystem-ideas/how-do-i-write-a-feature-request/idi-p/12384447
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I know that LR can easily find images that have been converted to B&W in the develop module. But I want to find all images monochrome such as scans of old prints or photos converted to B&W in another app. Can this be done?
Thx
That could be done easely if they want.
I am looking for a way to filter bracketing exposure .
I usually treat -2 different from 0 and + 2 stop.
(request has been made already)
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That could be done easely if they want.
I am looking for a way to filter bracketing exposure .
I usually treat -2 different from 0 and + 2 stop.
(request has been made already)
Here you go: https://regex.info/blog/lightroom-goodies/extended-search
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I asked ChatGPT to write a program that would do this - flag monochrome images. And within a few minutes it did so! I am very impressed! I have not tried it because I am not set up to run Python programs, but it certainly looks good.
It works by looping thru all the pixels in an image and comparing the R G and B values for each pixel. If they are the same or within a user-specified tolerance, it flags the image as mono. It can be limited to a random subset of pixels to reduce processing time. I have not tried it as I am not set up to run Python programs.
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For this to work on Lightroom you would have to render the images first, or have a program smart enought to determine what would the settings in the catalog do to the original file.
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For this to work on Lightroom you would have to render the images first, or have a program smart enought to determine what would the settings in the catalog do to the original file.
It is not meant to integrate with LR. Just with JPG and TIFF files. It outputs a list of the files it tags as mono. Very basic to be sure.
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Just FYI... I just tripped over a YouTube video on something called digikam (https://docs.digikam.org/en/)
It claims to have the ability to find monochrome or near monochrome images based on RGB values.
Have not tried it. Have not looked for proof in the website. Don't know what file formats if can handle.