[indii.org]

Bayesian Learning of Continuous-Time Dynamical Systems

Lawrence — Sat, 27 Jun 2009 04:16:59 +0000

I’ve posted the final version of my PhD thesis, "Bayesian Learning of Continuous-Time Dynamical Systems, with Applications in Functional Magnetic Resonance Imaging" to the research page. Now assessed, corrected and passed!

Note that this may serve as a useful manual for some of the detail behind the algorithms of the dysii Dynamic Systems Library.

New Paint Shop Pro plug-in for tintii

Lawrence — Thu, 07 May 2009 11:30:20 +0000

Version 2.1.0 of the tintii photo filter has just been released, extending compatibility of its plug-in version beyond Adobe® Photoshop® to Corel® Paint Shop Pro®. This should make the tool accessible to a much wider audience who wish to work within the space of these powerful graphics tools rather than through the standalone tintii interface, still available for free.

The new release additionally fixes a possible crash bug in the Photoshop plug-in when using the filter with scripting commands. Consequently, it is a recommended upgrade for those using a previous version of the Photoshop plug-in — simply uninstall your existing version and install this new version. 2.1.0 does not contain any updates to the free version on either Windows or Linux.

Documentation will be updated in time to include more information on the new Paint Shop Pro plug-in. Until then, please direct any queries to support@indii.org.

tintii documentation online

Lawrence — Tue, 05 May 2009 00:11:09 +0000

tintii documentation is now available online. This is the same documentation as available in the download itself, although may be more accessible to people in this form.

Minor tintii update

Lawrence — Mon, 04 May 2009 12:26:59 +0000

I’ve released a very minor update to tintii, updating an incorrect link in the registration dialog, and allowing the use of any file extension when opening or saving images. Crosses a few things off the to-do list, but if you’re already happily using tintii without problems, you needn’t bother yourself with the upgrade at this stage.

Are your tintii photos on flickr?

Lawrence — Mon, 13 Apr 2009 06:36:20 +0000

A quick request out to tintii users on flickr — any photos that you’ve put up where you’ve used tintii somewhere in the process of preparation, please tag with "tintii". What I’d like to do is get a group together soon to collect these examples together into one place. There’s a certain critical mass needed for such a group to be successful, so we’ll just start with this simple tagging scheme for now to see if there are enough of us out there.

Please drop me an email to let me know if you have tintii photos up on other websites, or even just send your work to me, it’s always great to see!

Tint 2, with Photoshop plug-in, now available

Lawrence — Tue, 17 Mar 2009 12:44:35 +0000

Version 2 of Tint Photo Editor, redubbed tintii, has now been released. This version marks a major upgrade to the software, most particularly with the inclusion of a Photoshop plug-in.

tintii is a smart photo filter for striking colour select effects. Also known as colour popping, think Schindler’s List’s little girl in red, or the dramatic style of Sin City. The new release includes:

An overhauled interface, quicker and more intuitive to use.
A Photoshop plug-in to unleash the power of tintii in conjunction with Adobe’s juggernaut image editing suite.
Orders of magnitude improved performance that now facilitates real-time editing.
New post-processing tools to give finer control over the filter effect, and particularly handle whispy hair and other difficult edging tasks.

The standalone version of tintii remains free, open source software available on both Linux and Windows. The Photoshop plug-in, available only on Windows, requires the purchase of a registration key in order to activate. To retail at a regular price of AU$29, for a limited time it will be on offer at AU$14 (approximately US$9, GB£7 or EU€7) to mark its first release.

Example applications available for dysii

Lawrence — Wed, 07 Jan 2009 17:16:31 +0000

Two example applications have been made available for dysii, a toy linear model and more elaborate double well stochastic differential model. The former of these will serve as a useful tutorial example for those wanting to learn to use the library. The latter is a more complex application with a number of features that make it ideal as a template for more serious work.

dysii 1.4.0 released

Lawrence — Wed, 17 Dec 2008 15:53:03 +0000

Version 1.4.0 of the dysii Dynamic Systems Library has been released. This is a major new release with a number of additional features and performance enhancements, as well as representing a consolidation of code and maturation of much of the API.

Particular new features include:

The kernel forward-backward and two-filter smoothers, suitable for fast, large-scale approximate inference in continuous-time stochastic models, as documented in my recent PhD thesis.
Overhauled kd tree implementation, featuring distributed partitioning, dual-tree and self-tree evaluations, particularly useful for the new smoothers above.
Improved stochastic Runge-Kutta and new Euler-Maruyama method for integrating stochastic differential equations.
Performance improvements resulting from continued profiling, including more aggressive inlining and less dependence on virtuals.
A new installation guide, available in the INSTALL.txt file of the distribution. Also note that with Boost 1.35 now released, dysii no longer requires the latest CVS of Boost, making it much simpler to install.

Full details are included in the VERSION.txt file of the distribution.

A couple of examples of applications using dysii are expected to be released within a matter of days also. These should provide an excellent starting point for those wishing to use the library for their own work.

Thesis available

Lawrence — Mon, 15 Dec 2008 17:59:40 +0000

I’ve made my PhD thesis available on the research page, "Bayesian Learning of Continuous Time Dynamical Systems (with Applications in Functional Magnetic Resonance Imaging)". The thesis considers Bayesian filtering and smoothing for state and parameter estimation in general non-linear, non-Gaussian systems using stochastic differential models. It is the theoretical basis for impending updates to the dysii Dynamic Systems Library, including the kernel forward-backward and kernel two-filter smoothers, and distributed implementation of particle filters and kd trees.

I should note that this should be considered a draft version, as it is yet to be examined, and corrections may need to be made after it is. I’m providing it here mainly for the purposes of documenting dysii at this stage.

South West Safari

Lawrence — Mon, 01 Dec 2008 17:28:46 +0000

I’ve finally finished the long upload of photos from our recent trip around southern Africa — Johannesburg to Cape Town — 7,200km through South Africa, Botswana, Zimbabwe, Zambia and Namibia. I purchased a new 300mm lens for the occasion to try a bit of wildlife shooting on our game drives, and managed what I hope are some nice shots. Other challenges were trying to capture the most beautiful sunsets I’ve ever witnessed, and picking just a few of so many inspiring scenes in the Namib desert, which turned out not to disappoint as the "photographer’s dream" we were told it was.

Here’s a taste, but see the photography page for the full set: