image height + width attributes in markdown_github output

[peterjc]

According to recent commit 244cd56 pandoc 1.16 will add basic support for image sizes.

I would like to specify image sizes for GitHub Flavour Markdown (GFM) and GitHub Pages rendered with Jekyll, using the output from pandoc.

Apparently GitHub briefly supported their own syntax for image sizes in GFM, but now an HTML snippet is required - see http://stackoverflow.com/questions/24383700/resize-image-in-the-wiki-of-github-using-markdown or https://gist.github.com/uupaa/f77d2bcf4dc7a294d109

i.e. If the image has no size information, continue to produce a classic markdown image. However, if the height or width is specified, in order to get a useful image displayed via GitHub, substitute the HTML snippet.

[peterjc]

A few examples using the GFM as implemented in the GitHub issue tracker (close to but not identical to GitHub Pages rendered with Jekyll).

No scaling, use a standard markdown image ![test](https://github.com/favicon.ico)

Defunct GFM, ![test](https://github.com/favicon.ico | width=48)


Another Markdown variant's style which does not work with GFM, ![test](https://github.com/favicon.ico =24x48)


Sadly this kramdown variant does not work with GFM, ![test](https://github.com/favicon.ico){:height="24px" width="48px"}

{:height="24px" width="48px"}

No scaling, with HTML <img src="https://github.com/favicon.ico">

Setting width to 48, with HTML <img src="https://github.com/favicon.ico" width="48">

Setting height to 24, with HTML <img src="https://github.com/favicon.ico" height="24">

Setting height to 24, and width to 48, with HTML <img src="https://github.com/favicon.ico" height="24" width="48">

[mb21]

markdown_github is defined as a bunch of extensions that are enabled (see the README). The width and height (and other) image attributes are enabled in the link_attributes extension (not enabled for markdown_github, so they are dropped).

So to support the requested feature, we'd have to create a new extension called github_images or so and change the Markdown writer accordingly.

[peterjc]

Thanks for your architectural insights - this sounds non-trivial then.

[jgm]

+++ Mauro Bieg [Nov 24 15 09:28 ]:

markdown_github is defined as a bunch of extensions that are enabled
(see the README). The width and height (and other) image attributes are
enabled in the link_attributes extension (not enabled for
markdown_github, so they are dropped).

So to support the requested feature, we'd have to create a new
extension called github_images or so and change the Markdown writer
accordingly.

I'm not sure why---all flavors of Markdown accept raw HTML,
so the plan of using HTML for images with attributes makes
sense without a new extension (well, we'd use the existing
raw_html extension).

This would become the default treatment not just for
markdown_github but for all markdowns without
link_attributes.

[mb21]

Right, of course. I didn't think of the raw_html extension...

[peterjc]

Lovely - thanks!

[zhangbg]

Thanks, it work!

[vishi9780]

is there is any way to resize the gif image

[regalstreak]

Resize gifs using the same way you resize images using the <img> tag

<img src="https://media.giphy.com/media/cFkiFMDg3iFoI/giphy.gif" width="300" />