$ dot -Tpng input.dot
PNG
Portable Network Graphics
Produces output in the PNG (Portable Network Graphics) format.
(25 November 2014) A standard Graphviz installation will render using both the Cairo and GD library. By mixing the rendering and formatting of these libraries, one can achieve different variations in the output.
-Tpng:gd(or-Tpng:gd:gd)- Indexed color, no antialiasing
-Tpng:cairo:gd- Indexed color, with antialiasing
-Tpng(or-Tpng:cairo)- True color, with antialiasing
These options are listed in increasing order of image quality and output size.