A collection of ressources related to imgtools:
- Tcl/Tk: the official website
- The Tclers Wiki: a great ressource for Tcl coding
- Img: a Tk extension that adds support for many image formats
- tclexecomp: a TCL exectutable wrapper based on freewrap which includes imgtools
- ImageWorsener: the page has some excellent documents about the basics of
image resampling. They helped me a lot to write imgtools!