possible bug with string format unique

[fmw42]

IM 6.6.7-1 Q16 Mac OSX Tiger.

I might misunderstand this.

This works to get unique colors:

convert logo: -format "%k" info:
232


But this returns nothing:

convert logo: -format "%[unique]" info:

[magick]

%unique is a unique filename, not the unique number of colors in the image.

[anthony]

%[unique] is not defined on the offical Formating Percent Escapes page. As such I have absolutely no idea what it does!

%k on the other hand is defined on that page.

%k number of unique colors

Taking the programmers axiom : Use the source Luke!

Searching source "unique" is a special image meta-data properity, that can be associated with an image, like many of the other properities shown in an identify output. Searching further, it appears to be a properity associated with "delegates"...

Got it from the "delegates.xml" file... It represents -- unique temporary filename for delegates

What use that is, is another matter!