I basically never want captions attached to the images in my slide decks.  Either I'm showing some data or results, and will be explaining to the audience what the image shows, or the image is decorative.  But I also almost always want the image horizontally centered, especially if the point of the slide is to display some data or results.  

Per the answer to #233 , Quarto respects pandoc's distinction between images and figures:  figures have captions, images don't.  Figures have a convenient global option for horizontal alignment, `fig-align`.  Images don't have anything like this global option.  So the only way to center align images is to add `fig-align="center"` as an attribute to every individual image.  (Or I could spend a few hours figuring out Quarto's theming, which seems kind of overkill.) 
2022-05-04T21:00:14Z
dhicks
closed
[feature request] Global options for image alignment for revealjs
https://github.com/quarto-dev/quarto-cli/issues/799