Imaginative name maybe (actually stands for Photon General Toolkit), PHGTK is the latest release of the Photon-derived extensions FJPEG, FGIF and FPNG from David Westbury.
Using these extensions, you can convert .JPG, .PNG and .GIF graphics files to QL _pic graphics files. PIC files are like QL screens or SMSQ/E BGIMAGE files, except that they have an additional 10 byte preamble which includes details such as dimensions in pixels, line increment bytes and mode number to help remove the ambiguity involved in loading screens of unknown resolutions and colour depth.
The extensions are implemented as BASIC functions to make it easy to add JPG, GIF and PNG handling facilities for your BASIC programs. They are one-way conversions, i.e. only convert from those formats to QL PIC files, but you can’t convert PIC files to one of those formats, sadly.
The latest version of PHGTK ads multi-frame GIF conversion and allows you to either extract a specified frame or the whole lot and even lets you specify “QL ticks” between frames for simple animation of PIC files.
Download PHGTK from the Graphics page on my website at http://www.dilwyn.me.uk/graphics/index.html (under Photon)