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Archive for February, 2011

Episode 32 of TechBytes: Desktop Environments, Computer Games, Android and Ubuntu as the ‘New Linux’, Copyright Mentality

TechBytes

Direct download as Ogg (2:06:13, 37.1 MB) | Direct download as MP3 (57.8 MB)

Summary: Tim and Roy talk about the subjects above and apologise for irregular show releases

IN THIS belated recording of the show, Tim and Roy talk about a plethora of subjects ranging from Free/open source software to matters of law and economics. Due to Tim’s busy schedule at work and around the house we have not released many new episodes recently, not even show notes for the previous episode (Tim is hopefully catching up by now). Gordon was absent when Tim had returned online and we hope he’ll be back for the next show.

Here are the show notes for tonight’s episode.

RSS 64x64The show ends with our default track. We hope you will join us for future shows and consider subscribing to the show via the RSS feed. You can also visit our archives for past shows. If you have an Identi.ca account, consider subscribing to TechBytes in order to keep up to date.

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TechBytes Episode 31: Nokia-Microsoft and Thoughts on Software/Games

TechBytes

Direct download as Ogg (1:41:57, 31.0 MB) | Direct download as MP3 (46.7 MB)

Summary: Tim and Roy discuss the Nokia-Microsoft deal and then argue about the use of question marks in headlines; they end up talking about so-called ‘piracy’ and even nostalgic games

TONIGHT’S show deals with the deal that’s impossible to ignore and then turns to other topics, altogether departing from the focus of the show at times.

RSS 64x64The show ends with our default track. We hope you will join us for future shows and consider subscribing to the show via the RSS feed. You can also visit our archives for past shows. If you have an Identi.ca account, consider subscribing to TechBytes in order to keep up to date.

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TechBytes Episode 30, Starting with FOSDEM 2011

TechBytes

Direct download as Ogg (2:02:52 37.3 MB) | Direct download as MP3 (56.2 MB)

Summary: Tim, Gordon, and Roy catch up with GNU/Linux vs Microsoft (or vice versa) news and then drift further away into some other topics

TONIGHT’S scheduled-not-so-planned-but-spontaneous show covered mostly GNU/Linux-related issues like Microsoft sponsorship of Linux and FOSS events, the situation at Nokia, Microsoft MVPs, Windows versus GNU/Linux at work, Debian’s new release, Linux Mint, uniformity across GNU/Linux environments, filesharing-based business models, Anonymous, and a few more issues. Corresponding articles will be linked very shortly in OpenBytes‘ show notes.

RSS 64x64The show ends with our default track. We hope you will join us for future shows and consider subscribing to the show via the RSS feed. You can also visit our archives for past shows. If you have an Identi.ca account, consider subscribing to TechBytes in order to keep up to date.

As embedded (HTML5):

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Ogg Theora
(There is also an MP3 version)

GNOME From KDE vs KDE From GNOME

Today I set up my alternative machine in a way which enables me to get the best of GNOME and KDE. It was set up in a way that I never tried before. Back in 2001 or thereabouts I would have gnome-panel imported into my desktop session (from another computer) and I repeated this type of practice locally around 2005-2007 when I wanted my KDE desktop to also have gnome-panel and therefore allow easy access to GNOME-side administration tools or applications. Today I tried something different altogether by installing KDE alongside GNOME and then running plasma-desktop in GNOME, which obviously imported panels and the background utilities, including 2 folderview plasmoids that import directories over SSH (the remote server on which I run workloads).

The bottom line is, there need not be a strict choice between GNOME and KDE. Both are compatible with one another and can run alongside one another in the very same session. In this case, it’s a dual-head machine with free graphics drivers and I might post some screenshots soon. This helps debunk the myth of incompatible desktop environments.

3-D Face Recognition

Al-Osaimi paper

From Al-Osaimi et al., IJCV 2008

Summary: My attempt to reproduce some of the results of F. Al-Osaimi et al. and furthermore improve them using other methods and different datasets (with a 3-D scanner at our disposal)

THIS post provides some background about my next (current) research project, which deals with non-medical applications. The previous project dealt with cardiac imaging and I’ve packaged that code and published it along with other data that may be useful.

The group of A. Mian has done some fantastic work recently on 3-D face recognition and I shall attempt to reproduce some results with a NIST database. In their paper “An Expression Deformation Approach to Non-rigid 3D Face Recognition,” F. Al-Osaimi, M. Bennamoun, and A. Mian explain some good results from experiements that apply PCA to face images (paper published online in September 2008 by a leading computer vision journal, but access is restricted, so there is no link, either… unless one uses this copy).

Since I have extensive experience with NRR, PCA, and statistical models in general, this project suits me better than some previous ones. I have done limited work on analysis applied to sets of face images that are only rigidly or affinely registered.

The paper from the group in question is 22 pages long in the raw form and about 15 in IJCV. The abstract describes an idea and quantifies some results using known benchmarks and the “FRGC v2.0 dataset”. Then, the method is alluded to vaguely and not formalised until later. The phrasing could be improved somewhat to avoid repetition, e.g. in the following paragraph containing parts like: “2D face recognition has been extensively researched in the last two decades. However, unlike 3D face recognition its accuracy is adversely affected by many factors such as illumination and scale variations. In addition, 2D images undergoes affine transformations during acquisition. Moreover, handling pose variations in 3D scans is more feasible than 2D images. It is believed that 3D face recognition has the potential for more accuracy than 2D face recognition (Bowyer et al. 2006). On the other hand, the acquisition of 2D images is less intrusive than 3D acquisition. However, 3D acquisition technologies are continuously becoming cheaper and less intrusive (The International Conference on 3D Digital Imaging and Modeling, 1997–2007).”

“Most of the approaches in the literature are rigid,” says the text in page 2, just before the overview which states: “The main contribution of this paper is a non-rigid 3D face recognition approach. This approach robustly models the expression patterns of the human face and applies the model to morph out facial expressions from a 3D scan of a probe face before matching. Robust expression modeling and subsequent morphing gives our approach a better ability in differentiating between expression deformations and interpersonal disparities. Consequently, more interpersonal disparities are preserved for the matching stage leading to better recognition performance.”

The background section is followed by some classification of existing work, concluding with: “Our approach also falls into this category i.e. non-rigid 3D face recognition.”

1.1 presents a very good summary of related work and 1.2 a clear overview of the method and the ideas behind it, accompanied by a helpful diagram at the bottom of page 3 (Figure 1). The strategy is to use pairs of image of the same individuals, normalising them a bit, and then applying PCA to reduce the dimensionality that characterises expression variation.

Section 2 in page 4 starts by describing pre-processing steps that are essential yet specific to the limitation of the FRGC v.20 dataset. Page 5 starts presenting some visual examples of the approach, with some equations relating to PCA (along with more visual examples) in pages 6 and 7.

Section 3 begins to deal with some other experiments that are not just dealing with models in synthesis mode. The same dataset is being used (with about 5,000 3-D faces), but more data gets added to it. To quote, “The dataset is composed of two partitions: the training partition (943 scans) and the evaluation partition (4007 scans). [..] The FRGC dataset was augmented by 3006 scans that were acquired using a Minolta vivid scanner in our laboratory.”

Parameters and set sizes (those which are included) get tested in very large-scale experiments that yield ROC curves. These curves help show how to set the different parameters and enable one to measure advantages of one algorithm over another. Page 13 has some comparisons to other methods from the literature, with numbers summarised in a chart.

This is truly inspiring work and I shall spend the next few weeks learning from it as well as implementing something similar.

Linux Mint 10, Ubuntu 10.10, and Kubuntu 10.10

Linux Mint 10 Julia

TODAY I moved on to my next research project, which I will mention very briefly in the next post. As part of this move I’ve also made some distro changes. The servers are running Ubuntu, so for the sake of consistency I wanted to explore the latest and greatest of Ubuntu and its flavours/derivatives. I gave a go to 3 and spent some time working from them (not long enough an experience as yet).

Will it be 10 out of 10 for the 10.10 releases? What about Mint 10 (codename “Julia”)? I decided to try today, hopefully seeing how it all compares to Fedora 14, which I have used since it was released around the end of October. The change is motivated by needs of consistency; I also like to try different distributions and see what they are all about over time, for the sake of comparison. I might stop using Fedora for a while. It is still installed on a PC, but I moved all my important work files out of there, which means they’ll go out of sync over time.

A report about use will be posted at a later date (this is not a review but a post with quick impressions). The important points are that today I tried Linux Mint (very latest version, which is GNOME based) and latest Ubuntu+Kubuntu shortly afterwards. Linux Mint has this nice new feature (to me at least) that has it start the installation while the user enters installation options such as user details, location, etc. The menus and graphics (including icons and window decorators) are stunning. Setting up dual-head in Ubuntu without proprietary drivers was easy, in Kubuntu it’s still not as easy (getting twinview). Overall, since both share the very same base (even same packages for the most part, except those which are preinstalled), comparison in this case ought to rely on what’s above the hood, mostly user experience.

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