Does any of you know how to center the images in Nov mode?

The config I'm using (use-package nov :mode ("\\.epub\\'" . nov-mode) :preface (defun zoli/nov-font-setup () (face-remap-add-relative 'variable-pitch :family "ChareInk" :height 210) (setq line-spacing 0.1)) :hook (nov-mode . zoli/nov-font-setup) :custom (nov-text-width t)) The [https://depp.brause.cc/nov.el](https://depp.brause.cc/nov.el) website mentions something about custom rendering but the code is too difficult for me to understand. The justification of the text is fine. The only thing I want is to center the images in the EPUBs.

Ha, no effing way, of course there's an ebook reader.

As of Emacs 28.1, there's no built-in way to center an image accurately in Emacs, so you'll have to settle for a rough hack. (defun nov-center-images () "Center images in document." (let* ((pixel-buffer-width (shr-pixel-buffer-width)) match) (save-excursion (goto-char (point-min)) (while (setq match (text-property-search-forward 'display nil (lambda (_ p) (eq (car-safe p) 'image)))) (when-let ((size (car (image-size (prop-match-value match) 'pixels))) ((> size 150)) (center-pixel (floor (- pixel-buffer-width size) 2)) (center-pos (floor center-pixel (frame-char-width)))) (beginning-of-line) (indent-to center-pos) (end-of-line)))))) (add-hook 'nov-post-html-render-hook 'nov-center-images) This will center _all_ images (in nov) over 150px in width, even inline ones. To avoid this, you can add an additional condition to the `when-let` that checks if the image is the only DOM element in the line. (If you do, please reply here so I can use it too.) While we're talking about nov/shr, does someone know if there's a way to detect and invert image colors natively in Emacs? That is, without using imagemagick. I'd like to do this when using a dark theme.