Category Featured Images Extended (CFIX) can ensure that posts, category archive pages, widgets and other elements of your site will always display a thumbnail or featured image* when called upon to do so by themes, templates, and plugins.
If a featured image has been individually set for a post, it will be used. If a featured/thumbnail image has not been set for a post, CFIX will first try to supply an image from one of the post’s categories or tags. It will use a Yoast SEO “Primary” Category’s image if available. If no category or tag image is found, the plugin will look for a parent category with an image. Finally, if no linked or related post, category, tag, or parent category image is found, a particular fallback tag or category image can be used if set as “global fallback.”
This plugin was initially based on “Category Featured Images” (CFI) by Mattia Roccoberton. If you already have been using CFI, when you install this extended version, your already saved category image settings will be preserved and copied.
In CFI
In CFIX
NOTE: IF UPGRADING FROM CATEGORY FEATURED IMAGES, DE-ACTIVATE IT TO AVOID CONFLICTS
As a further precaution, do not uninstall CFI completely until you are sure that CFIX is working as expected for you.
* The terms “thumbnail” and “featured” are used somewhat interchangeably in WordPress, even though many featured/thumbnail images will be displayed at much larger than thumbnail size.
Check the CFIX home pages for additional background, examples, documentation, and usage tips… or to contact the developer directly.
All gratitude to Mattia Roccoberton for the basic code for his original Categorey Featured Images plug-in, which I had been using for years before I got around to extending it. Thanks to John Prusinski for recommending the Yoast SEO modification, encouraging me to implement it, and even throwing in a tip via Paypal! Thanks also to all of the developers and everyday code-hackers, far too numerous to name, upon whose work I have depended.