Vector graphics with Inkscape

Graphical concepts

A quote from the text (PCFB).

No longer can you submit a photo that looks right; it has to be a “CMYK image, with 300 DPI at printed dimension, saved as a TIFF with LZW compression”. The goal here is to introduce a software that can help with some of these requirements. Please refer to Chapter 17 for further depth than we go into here on graphics.

Vector and pixel images are probably concepts most biologists are familiar with. Pixel images (bitmap, raster) are a uniform grid of colored dots. In vector art a line can be defined by two endpoints. The vector representation has the advantage of being often easier to store. Also, the amount of information for vector art stays the same no matter how large the plot and as you zoom in vector art stays the same.

File formats that store vector based images include: PDF, EPS, SVG and AI. File formats that store pixel-based images are JPEG, PNG, TIFF, BMP and PSD. PDF, EPS and AI can store embedded pixel information (hybrid images).

It is always possible to go from vector to pixel art, but it is not so easy to go the other way. Another advantage of vector art is that pixel text is not easily retrieved by a machine.

Pixel art is everywhere (photos, machine output), however if we have to create a completely plot then there are a number of reasons to do so using vector graphics. Vector art is covered in chapter 18 of the book.


Inkscape uses the SVG (Scalable Vector Graphics) format for its files. SVG is an open standard widely supported by graphic software.


  • Inkscape can import other formats (e.g. PNG or EPS) then convert.
  • One could create a image in matplotlib (SVG,PDF etc) and import then annotate
  • Resizing of images
  • Adding text or shapes or colors to a bitmap