This is an ongoing project; we have considered or played with different inter-thread communication mechanisms: shared memory, pipes, common (thread) address space, RPC mechanisms such as RPC, Corba, .NET; and finally network sockets. All of those have advantages and disadvantages, both in terms of performance and in terms of portability.
If you are interested in this work, please contact firstname.lastname@example.org or email@example.com.
Here's an image display widget that imports an octave array (and possibly another array to serve as a colormap), and displays it alongside an X- and Y-axis cut. It allows zooming into the image, and cursor tracking with live updates of the X/Y cut plots, at interactive speeds (our test array is 400x400 elements):
This image shows the zoomed view:
The only custom part in this widget is the code to grab an octave array and pass it to Tcl. Everything else was done entirely in just 200 lines of Tcl, using the existing BLT widget for displaying the axis, X/Y graphs and colormap index.
BTW, this mechanism can be seen both as a GUI for octave programs (i.e. a way to create a GUI from within octave code), as well as a GUI for octave itself (by creating an appropriate text input and result display widgets in, say, .octaverc).
Here's an example of a VTK window created from within Octave's Tcl interpreter. The main interface window shows the sample data in 2D:
An additional window is provided for entering Octave commands. Pressing the 'Render' button brings up a VTK window with a 3D representation: