Searching for black and white photos in MacOS Photos app

Have you tried a Smart Album with

"Text is Monochrome?"

It's not perfect, but you can see above that I got a little over 200 hits, so it gets a bunch of them. You could add a "Monochrome" keyword to those, and then do a search for keyword "not monochrome" and see if you find others to add the keyword to. I got some Sepia pictures when I did that. So I manually picked those out and added the keyword. You can use Keyword Shortcuts to make it fast…

As to "why," there's no way we can answer that. My guess is that there are just too many ways that something can be monochrome. They're all really color, in a way, and Black & White is just a setting

in the editor.

léonie wrote:

You may want to send a feature request to Apple to add a category "Black and White" to the "Media Kind" collections. Feedback - Photos - Apple

When I search for "monochrome" I am getting not only faded color photos or sea colored B/W photos or night shots or winter photos with lots of snow, but also photos with glaring colors on a dark background,

I get the same sort of stuff-- it made me wonder what I meant by "monochrome." Black & White is easy, just no color anywhere-- but that would eliminate old sepia pictures and the like.

Super-cute Snow Bears!

I have many technically "color" images that are really grayscale to the human eye, so I guess some sort of AI must be used.

As a quick test I used GraphicConverter to convert a color .jpg to 8, 16 and 32 bit real grayscale image (32 bit seemed to require .tif output). It seems the following two tags might best sort grayscale images out of color images. That ICC-header:ColorSpaceData=GRAY could easily be replaced with some dummy color tag with GC, though. So maybe ColorComponents=1 is the most reliable method for this?

exiftool -a -G1 -s -ColorComponents -ColorSpaceData .
======== ./grayscale_32.tif
[ICC-header]    ColorSpaceData                  : GRAY
======== ./grayscale_08.jpg
[File]          ColorComponents                 : 1
======== ./grayscale_16.jpg
[File]          ColorComponents                 : 1
======== ./color.jpg
[File]          ColorComponents                 : 3

Matti Haveri wrote: … So maybe ColorComponents=1 is the most reliable method for this?

As you say, this doesn't really work for monochrome.

[1955. My father is the Master Sargent. I think that this was the entire Marine Corps contingent in Thailand]

This is clearly monochrome, but ColorComponents=3.

It looks like most monochrome pictures I have were scanned with the "color" setting. I found some scanned with the B&W setting, and those say ColorComponents=1.

Setting the B&W in Photos Edit keeps ColorComponents=3 in exports.

You may want to send a feature request to Apple to add a category "Black and White" to the "Media Kind" collections. Feedback - Photos - Apple

When I search for "monochrome" I am getting not only faded color photos or sea colored B/W photos or night shots or winter photos with lots of snow, but also photos with glaring colors on a dark background, for example:

I looked for monochrome pictures, and I found about 700, so the original search got less than a third of the monochrome pictures.

Boy, it's hard. I had to reject a lot of just faded old color pictures.

That looks promising, Matti. Thank you.