Downsampling
< Using Graphics >
Downsampling means to reduce the resolution of a picture to save space.
There are two simple, but otherwise undocumented modules:
grph-downsample
This MkIV module is not in the distribution, but you can download it from here. It expects the gm
tool from GraphicsMagick to be callable.
Copy grph-downsample.lua to .../texmf-local/tex/context/third/grph-downsample/grph-downsample.lua
Call context --generate
Copy hacker.jpg
to your directory.
Write this to downsample.tex
:
\loadluafile[grph-downsample] \setupexternalfigures[conversion=lowres.jpg, resolution=10] \starttext \externalfigure[hacker.jpg][width=5cm] \stoptext
The module extends \setupexternalfigures with the conversion
and resolution
keys. The former defines an extension to the filename, the latter the final resolution dpi. It works only if the width
or height
key of \externalfigure is defined.
conversion=lowres.jpg
in the above example creates a temporary file m_k_i_v_hacker.jpg_10.lowres.jpg
.