Fourier Transform

Live Fourier Transform for Windows

2011/08/16 // 6 Comments

[Ed: a new, completely rewritten version of this code can be found here, with a precompiled Windows version available at the bitbucket site courtesy of Joachim Kohlbrecher] Since entering paternity leave, I have had little time to come up with something new to post here. However, one colleague was so kind as to send me his Windows version of the live fourier transform program discussed before. His runs on his Lenovo laptop (but may be more widely applicable) and uses the Windows built-in Matlab webcam code. Framerates are markedly better than my OS X code, but memory requirements are significant and reinitialisation of the camera every few seconds generates a flash. The code is available here, with many thanks to Jakob R. Eltzholtz for making his code available. If you have suggested improvements or changes, please do not hesitate to contact Jakob and/or [...]

Live Fourier transform

2011/02/03 // 8 Comments

During some recent presentations, I have used a small matlab program giving me a live Fourier transform of the laptop camera input. It can be used in combination with some printed “structures” to show what we would see on a SAXS or WAXS detector. The idea is not mine, I heard that it was used by dr. Henrik Lemke for his Ph.D. defense to show the effects of lattice strain on the diffraction pattern. It turns out to be quite popular with the audience so far, so I will post the code for Matlab running on a macbook Pro here. Feel fee to use the code. I will also make a short movie showing one example of how to use it. I am sure you can think of many other useful purposes for it! The package is here: FT_cam_package Since it is so specific in its application, there is no documentation. Also, run “FTcamdemo” and the rest should be quite self-explanatory in the GUI that comes up. This package uses (and comes with) camera image capture code (Java) by Kalle Kempe and [...]