Get sizes from image files for better LaTeX output

[mgeier]

See #12.

This mostly works, but there are a few remaining problems:

• Getting the size doesn't seem to work for PDF images (LaTeX: Make PDF images a bit smaller #229)

• data: URIs don't work (Get image size from "data:" URIs #230)

• images are unnecessarily turned into links in HTML output (see Annoying links to original on scaled images sphinx-doc/sphinx#4229 and the html_scaled_image_link option). For now, I've used html_scaled_image_link in the docs. (Avoid using html_scaled_image_link #232)

• The maximum size is not constrained (nbconvert does that). \sphinxincludegraphics has this feature built-in, but it works only if no height/width is given (see sphinx.sty). (LaTeX: Constrain maximum image size #231)

[rddaz2013]

For a normal Image the with command within markdown image helps.

.[Bild P01(IMG_20180619_140351208.jpg){ width=280px }

but the { width=280px } shows up in the html output as text^^ in latex it is working.

[mgeier]

@rddaz2013 With my current solution (see 3f2a29c) the image size is taken from the file itself, no need to explicitly specify it.

The syntax you are mentioning would be a Markdown extension, you can try to ask the Jupyter people if such a thing is planned.

Alternatively, HTML syntax could be used, see #52.