[vtkusers] Generate in-memory JPEG images in Python

[Shead, Timothy]

On Aug 29, 2011, at 9:18 PM, Shead, Timothy wrote:

> Gang:
> 
> I'm experimenting with generating an offscreen JPEG image on a web-server using VTK and Python, but I'm hung-up on how to convert the vtkUnsignedCharArray returned by vtkJPEGWriter::GetResult() into a Python string or buffer.  Any thoughts?  I see that it's easy to create a numpy array that points to the same memory, maybe there's something I could do with it?

OK, answering my own question - you can convert vtkUnsignedCharArray to a numpy.ndarray using vtk.util.numpy_support.vtk_to_numpy(), then use the numpy array's tostring() method.  Feedback welcome if there's anything more direct.

Cheers,
Tim

Timothy M. Shead
Sandia National Laboratories
1461, Scalable Analysis and Visualization