< Using–Graphics >
If you’re using ConTeXt for complex layout tasks, you need to calculate with image sizes. Often it makes sense to use Lua functions.
Beware, TeX calculates internally in "scaled points" (sp), 1 sp = 1/65536 pt.
Measures in pure ConTeXt
You can get at a picture’s dimensions with one line of TeX code:
\setupexternalfigures[location=default] % necessary to find pictures in tree \getfiguredimensions[hacker.jpg]
This defines a bunch of variables: