Markdown supports images and tables. It may depend on the rendered though. The GitHub flavour of Markdown supports this for example and I expect Latex supports it too. If existing tools don’t exist to get the height of elements you can probably make it yourself fairly easily if you you the specific font and styling the renderer uses. You’d just have to parse the file, which is basically plain text, and run the same calculations the renderer would. For which approximation might be fine depending on the use case