CommonMark has yet to implement any nifty image features. MultiMarkdown has some great ones:
The basic syntax for images in Markdown is:
![Alt text](/path/to/img.jpg) ![Alt text](/path/to/img.jpg "Optional title") ![Alt text][id] [id]: url/to/image "Optional title attribute"
In addition to the attributes we can use with MultiMarkdown (see thread here), MultiMarkdown also adds a few additional things. If an image is the only thing in a paragraph, it is treated as a block level element:
This image (![Alt text](/path/to/img.jpg)) is different than the following image: ![Alt text](/path/to/img.jpg)
The resulting HTML is:
<p>This image (<img src="/path/to/img.jpg" alt="Alt text" />) is different than the following image:</p> <figure> <img src="/path/to/img.jpg" alt="Alt text" /> <figcaption>Alt text</figcaption> </figure>
The first one would be an inline image. The second one (in HTML) would be wrapped in an HTML figure element. In this case, the alt text is also used as a figure caption, and can contain MultiMarkdown syntax (e.g. bold, emph, etc.). The alt text is not specifically designed to limit which MultiMarkdown is supported, but there will be limits and block level elements aren’t supported.