The Streeb-Greebling Diaries

New cameras ready for robotic excursions

2009-07-08T15:22:00.000-07:00

All four new cameras are now fitted to the pan and tilt head of GROK2, and the robot is once again ready to run on Linux. The new cameras are Quickcam Pro 9000's, with all the casing and microphones removed.

On the arbitrary nature of memorials

2009-07-07T02:49:00.000-07:00

The BBC web site has an article on a memorial to the people who were killed in the 7/7 bombings of 2005. It doesn't look like a very imaginative sculpture - just some poles stuck in the ground. It doesn't even seem to represent "52 unique individuals" as claimed, since all the poles are the same.

The way that we choose to memorialise certain things and not others seems very arbitrary to me. So for example a similar number of people are killed in traffic accidents every day, or die whilst waiting to receive hostpital treatment, but these people don't usually have statues - artistically interesting, or otherwise - erected in their memory.

So what seems to matter as far as memorials are concerned is not just the number of people killed, nor whether they were "innocent" or "non-political", but whether the event in which they died was itself of a highly political nature.

Needless to say, if I were unfortunate enough to be killed in an event resembling 7/7 I would't wish to be represented as a featureless grey monolith.

Four years on from 7/7 there still remain some inadequetely explained components to the story, and the lack of a public enquiry into exactly what happened that day has meant that various possible alternative explanations, questions about what the security services knew about the bombers and miscellaneous conspirarcy theories have arrisen. In hindsight I think that not holding a public enquiry was a mistake, and that probably the best policy when something like this happens would be to open source the evidence as soon as it becomes available, so that the wilder theories can be clearly ruled out.

GROK2 gets new cameras

2009-07-05T09:06:00.000-07:00

I've been searching for possible replacement cameras for GROK2 for the last couple of years, and it's been quite tricky because the image quality of the Creative Webcam NX Ultra is quite hard to beat. Had it not been for recent kernel changes which meant that the existing cameras no longer worked on Linux I probably would have just carried on using them.

The new cameras are Quickcam Pro 9000's. These have an unusually elongated circuit board, so one of the cameras is mounted upside down with the image being inverted in software. The mounting holes on the circuit boards are asymmetrical, hence the rather skewed appearance of the wooden bar that they're fixed onto when one board is upside down.

The new appearance is nerdier and more Cog-like, and the protective hood will be reattached once I've replaced both sets of cameras.

Until recently I'd been thinking of using the Minoru stereo webcams as replacements, but after experimenting with these, including changing the lenses for wide angle versions, it seems that the 6cm baseline is just too short to get very good depth perception beyond a metre or so. The Minoru might still be used though on the Rodney robot.

I've increased the separation between the new cameras to 12cm, in order to get a little more ranging performance. For this robot close up recognition isn't the main research goal.

The new cameras are considerably smaller, and can be tilted almost vertically down towards the floor. They also have a wider exposure range, which means that in theory the robot could be used outdoors, although at present I'm not intending to do that.

Battle of the browsers

2009-07-05T01:55:00.000-07:00

Interesting to see that in different countries there's a huge difference in the search volume for IE and firefox. So in Ireland, South Korea and to a lesser extent in China there's a larger number of searchers for IE, but in India, Russia, Europe and the far east more people are searching for Firefox. Notice that the pattern of searches in Hong Kong are opposite to those in the rest of China.

Sign of the times

2009-07-05T01:36:00.000-07:00

Three quarters of your pay is belonging to us

2009-07-04T14:41:00.000-07:00

This kind of thing seems to be becoming quite common. I expect that for most employees on ordinary wage levels a pay cut of 75% would simply be impractical, because the cost of living is not falling at a similarly rapid rate - in fact retail prices seem to be continuing to rise (aka stagflation).

A month or so ago, when I was still full time employed myself, there were many confident-sounding predictions that the economy would begin to turn around in the second half of 2009. Whether or not that will actually happen remains to be seen, but recessions don't last indefinitely so sooner or later things will begin to pick back up again.

Wiggle it

2009-07-03T11:00:00.000-07:00

More progress on the Willow Garage robot. Plugging yourself in is actually quite a hard manipulation task, which is sometimes even challenging for humans. I notice that in the video the wall socket cover is cracked, so maybe the robot bashed it too hard during development.

There would be easier ways to do this, such as having a special recharging station, as used by Roombas and other mobile robots. However, being able to use regular mains sockets would be a significant advantage in terms of maximising the ease of deployment, since such sockets usually exist in every room and require no special setup.

Since I have far more free time at present than would usually be the case I may investigate the possibility of using their Robot Operating System. I have my own system, written in C#, which does substantially the same sort of message passing between processes, but if it looks like there's something out there which is reasonably easy to use and has an existing development community, it might be a better long term strategy to combine efforts.

Maybe there ought to be a scientific term for "wiggling". You could call it "off-axis rotational re-alignment" or "closed loop manipulator pose optimisation".

Swine flu: avoid sensationalism and check the figures

2009-07-03T10:16:00.000-07:00

It seems that there's still a lot of media hype going on with regard to swine flu, with claims being made that it's "unstoppable" and out of control. As I've mentioned previously the main thing that you need to focus on isn't how many people are contracting the illness but how many actually die as a direct consequence.

The Wikipedia entry for 2009 flu pandemic gives a set of figures which I havn't seen reported in any of the mainstream media articles (which seem to be mostly only succeeding in promoting fear and hysteria). Assuming that these figures are reasonably accurate the mortality rate worldwide is around 0.5%, or 1 in 200, with the numbers varying from one country to the next (in the UK it's only 0.05%). This is higher than so-called "seasonal" flu, but not by a margin great enough to be convincingly beyond measurement error, since there will of course be many people who become sick and either don't know that it's swine flu, are never tested, or choose not to report it and subsequently recover. Realistically if I were to get flu-like symptoms and am not specifically tested for H1N1, how am I going to know the difference? I'm probably not.

Compare this with avian flu, and there's a gigantic difference in mortality. In the case of H5N1 over half of those people who contracted it died within a few weeks.

So I'd say that swine flu is only something worth worrying about if it mutates into a form with a significantly higher mortality rate. Thus far those people who have been victims seem to have largely fallen into the traditional categories of those at the extreme ends of the age range, or who have preexisting medical conditions which compromise their immunity.

Although it's claimed that 40 people per day could die from swine flu by the end of August, to put this in context - something which mainstream media reporters never do - from the latest figures I could find (2002) on the National Statistics website about 100 people are killed or seriously injured every day in road accidents in the UK - almost equivalent to two 7/7 terrorist attacks (which really makes me wonder about the cost/benefit of all the anti terror measures taken in the last five years).

A seriously hard object tracking task

2009-07-02T04:54:00.000-07:00

As you can see the human brain is far better at detecting and tracking separate objects than computers currently are.

Right next to the Beluga

2009-07-01T08:43:00.000-07:00

More singularitarians spotted, right next to the Beluga.

"The age of television is ending"

2009-06-27T09:00:00.000-07:00

Even the BBC now admits what I've been saying probably for the last decade. The age of television is drawing to a close. This doesn't mean that TV will disappear entirely but, like radio before it, it will merely become less important as a source of entertainment and news.

In my opinion the BBC has no particularly "unique status", and the way it's funded is archaic and makes little sense in the modern era of subscription services. Certainly the type of "public service broadcasting" which existed when I was growing up, where you had very large audiences watching one or two TV channels, is now very much dead and not coming back under any foreseeable circumstances.

Whilst one media format declines others are ascendant. Video games and general internet usage have greatly increased in popularity, but the real phase shift is going to come once augmented reality becomes a consumer commodity. Augmented reality entertainment, delivered by wearing a device similar to the Eyetap with a built in gyro/accelerometer so that it knows your head orientation relative to gravity, I think is going to be a gigantic industry producing experiences which are highly compelling and where the style of interaction is very natural.

Lenses

2009-06-26T06:22:00.000-07:00

Here are the M12 lenses which I've tried using so far with the Minoru webcam. The 3.6mm lens fits, but gives a field of view smaller than the original lens. The 2.1mm lens does give a significantly wider field of view, but also seems to have a focus longer than the height of the lens holder above the circuit board. To be able to use the 2.1mm lens I would need to either use a different lens mounting, or some sort of extension. The trouble with trying to make an extension is that without precision machining equipment, armed primarily only as a pre-industrial craftsman with a drill and junior hacksaw, it would be hard to make something with enough accuracy to get good alignment - and good alignment is very important for stereo vision in order to ensure that the epipolar constraint applies.

I've ordered yet another set of wide angle lenses with only 5mm "back focus". Presumably "back focus length" means the distance between the back of the lens and the CCD/CMOS chip. Unfortunately without detailed drawings, which are almost never available, it's hard to know in advance whether a given lens type will be suitable, so it's mostly just down to trial and error. Fortunately though plastic camera lenses intended for webcams or security cameras are quite cheap, so if they turn out not to be appropriate it's no great financial loss.

In this picture you can see the infrared filter, which is normally a square piece of plastic superglued to the back of the lens.

Dear carbon mass...

2009-06-25T13:59:00.000-07:00

This made me laugh.

World builder

2009-06-25T10:41:00.001-07:00

World Builder from Bruce Branit on Vimeo.

Image processing mistakes as an artform

2009-06-25T03:55:00.000-07:00

I've entitled this one The Struggle for Agrarian Self-Actualization.

And this one is entitled Noospheric Disenfranchisement Al Dente.

Blair was aware of torture policy

2009-06-23T08:51:00.000-07:00

A story which seems to be all over the blogosphere, but doesn't appear to have been covered in the mainstream news outside of the original Guardian article, is that evidence has emerged that Tony Blair was aware that people were being tortured as part of his counter-terrorism policy. Allegedly the torture victims even included British citizens.

I expect that the new Iraq inquiry won't cover this, or if it does all the relevant documents will be withheld from public scrutiny in the name of "national security", or wotnot.

Probably the rebuttal that Blair did not "authorise" torture is (we hope) true, but being aware that it was going on under circumstances which could reasonably be described as being within his influence or control, and yet choosing not to intervene, would put him into territory of questionable legality. So it's not surprising that he feared a "show trial" if the Iraq inquiry were to be held in public.

Monodevelop goes full circle

2009-06-23T03:35:00.000-07:00

It now seems that there is a version of Monodevelop for Windows. This is ironic considering that MonoDevelop originally came from Sharpdevelop - an open source Windows based alternative to Visual Studio.

I suppose it's nice that there is a Windows version, since this encourages people away from the proprietary software. Whether there is really a significant demand for GTK/Mono applications on Windows though I think is questionable.

I've been using Mono and Monodevelop for over two years now, and when I started out it was far less controversial than it is today. From a technology point of view I think C# is a pretty good language, comparable to C++ or Java, but I do agree that there might be patent issues further down the line, especially since the implementation of Mono seems to significantly exceed the ECMA C# specification with extensions such as Windows.Forms. Fortunately though I don't expect my own projects to have a very large user base, and even if Microsoft were to do their worst, porting the code to another language would certainly be feasible. What's important as far as I'm concerned are the algorithms, not the specific language that they're implemented in.

Replacing webcam lenses

2009-06-23T03:00:00.000-07:00

My initial attempt at replacing the lenses on the Minoru webcam appears to be a complete FAIL. I've tried using a 90 degree FOV 3.6mm "camera board" lens, which fits perfectly well, but the results look like the following.

On the left is the original lens, on the right is the 90 degree FOV lens. As you can see the field of view on the right actually looks narrower than the original. The difference in colour is due to the new lens having no infrared filter attached. At this point I'm not really very concerned about not having an IR filter - in fact it may be an advantage in low lighting conditions.

I think the problem here may be the chip size. The "90 degree" figure may be assuming a larger CCD/CMOS sensor size than exists on the webcam.

Stereo vision with the Minoru webcam

2009-06-21T01:42:00.000-07:00

I now have a version of software suitable for use with the Minoru webcam. It's similar to earlier versions of sparse stereo correspondence, except that I've tried to optimize it for speed using binary descriptors for each detected image feature which can be compared very rapidly. Also the matching routine does not assume that it has access to both images at the same time - only sets of features and their descriptors. This means that it can be run in a relatively decentralised way which I can implement embedded onto the Surveyor SVS, where there is some limited amount of bandwidth between two otherwise independent camera boards.

Testing using the Minoru at 320x240 resolution this stereo correspondence algorithm is completely real time, running at frame rate speeds.

There are a couple of improvements upon previous sparse stereo implementations. I'm using an eigenimage-like method to compare the feature descriptors, which gives better discrimination between features which have many bits in common, and I'm also using both correlation and anti-correlation, as described by Read and Cumming. Good matches tend to correspond to local minima in correlation space and local maxima in anti-correlation space. If the maxima and minima don't occur together, it's probably a bad match.

Fun with electronics

2009-06-20T13:31:00.000-07:00

Although I do have a certain amount of electronics piled up in the vicinity I'm mostly a software engineer. However, when I was at school I had a friend who was just like the guys in this video and was always coming up with wacky electrical and/or computer projects. In 1983 he actually taught me some aspects of BBC BASIC during a series of boring history lessons. I think some time in the mid to late 1980s I sold my Sinclair ZX-80 to him and he used it to control some fancy disco-style LED lighting.

The Legend of Neil Robot Part 1 from Jeri Ellsworth on Vimeo.

Owen Rubin Shows "Kermit" Ataris Prototype Robot Pet from Jeri Ellsworth on Vimeo.

By the standards of the late 1970s the "Kermit" robot would have been ultra sophisticated, and pre-dates the MIT mobots of Brooks & co. You could argue that not much progress occurred in mobile robotics for at least another decade.

Decoy

2009-06-20T12:15:00.000-07:00

There has been such a huge media flap over the last month or so regarding politician's expense claims that this makes me suspicious that perhaps other more interesting stories might be being "buried" (to use the New Labour terminology).

One thing which has been underway is "quantitative easing", which as far as I can discern involves stealing massive amounts of cash from tax payers.

"The Bank of England started printing money in March and has now pumped an extra £75 billion into the economy to encourage lending, boost spending and stimulate growth."

Presumably eventually this spending splurge is going to be underwritten with tax money, and we can expect taxes to rise significantly over the next few years. Now I'm not trying to defend the politicians. What they did with their expenses was certainly dishonest and unethical, and in some cases possibly also illegal, but the amounts of money involved are dwarfed by the utter waste of quantitative easing and other questionable policies such as the national identity card. You may also wish to peruse some interesting economic statistics.

"The Labour government has thrown all of the fiscal rules out of the window and has embarked on a debt busting inflationary programme of money printing. The Bank of England having first been paralysed into inaction despite overwhelming evidence that interest rates should be cut in an orderly manner towards a target of 3%. Having acted too late have now slashed interest rates from 5% to 2% in less than 3 months. With expectation of further cuts to take interest rates to the target rate of 1% and highly likely lower still. All of these actions reek of nothing short of panic to prevent an 1930's style deflationary depression. The consequences of which will be at the very least stagflation and if the level of incompetence continues then highly likely hyper inflation along the lines of the 1970's starting during 2010 and continuing for many years thereafter."

Strange resurgence of internet utopianism

2009-06-19T11:49:00.000-07:00

It's as if the last 15 years of digital history never happened, as Gordo preaches a strange form of internet utopianism, saying that "You cannot have Rwanda again".

Due to what? Twitter?

As the internet and the world wide web were emerging into the collective public consciousness in the early 1990s there was a lot of talk about it having a radical democratising effect upon society. Some people thought that it would render nation states irrelevant, and that we would all become part of one big, happy, digitised global village. Others envisaged a sort of digital anarcho-capitalism in which conventional politics and politicians would be obsolete and where citizens could vote electronically in real time using computers or mobile phones to make collective decisions without the need for elected representatives or houses of parliament.

Unfortunately it didn't quite turn out that way, although it does appear that the internet has fostered greater communication between people in diverse areas of the world who would otherwise have never been aware of each other's existence.

I would like to believe that Twitter could prevent genocide, but sadly I don't think it can. What Gordo doesn't mention is that technology cuts both ways, and that were a genocide like the one which occurred in Rwanda to occur again internet communication could make it all the more rapid, efficient and coordinated (from the murderer's point of view). The assumption which is being made is that lack of information allows these things to happen. To some extent that's true, but I remember that at the time the Rwandan genocide was actually covered by the media and that people around the world were to a significant extent aware of what was going on. What was lacking was any action at the political level to intervene and prevent people from being slaughtered.

The question of how to prevent future genocides is a difficult one, which I think doesn't have an easy technological fix because it originates from deep seated weaknesses within human psychology - it's more of a firmware bug than a software one.

There are some reasons to be optimistic though. I think it's almost certain that new genocides will occur in future, and that they will take place within the context of the modern digital communications infrastructure. This opens up possibility of doing data mining - a sort of memetic archeology - to discover exactly how certain ideas are transmitted between people and characterise the trajectory of an idea as it undergoes positive feedback spreading across multiple minds. As memetics becomes less of a hand-waving exercise for philosophers and more of a science it may be possible to identify the spread of harmful ideologies and either stop them before they manage to take hold or apply a perturbation which causes the meme to mutate into a less harmful form. From the vantage point of the present it's very unclear how this would be practically achieved, but in principle it might be something which becomes possible.

Robots for small and medium sized businesses

2009-06-17T10:06:00.000-07:00

It's to be expected that as conventional industrial robotics becomes cheaper - mainly due to falling costs of the servo drives and software - that the sorts of automation previously only used in large factories will also become available to smaller businesses.

Security related vision system applications: a policy statement

2009-06-16T06:38:00.000-07:00

Whilst looking for a potential new job in the last week or so I've been contacted by several organizations (in one case repeatedly by the same company) in relation to security related applications of computer vision. The salaries quoted seem unusually high for a software engineer (software engineers are usually somewhere marginally above cleaners and receptionists in the salary food chain), but upon examining the web sites of the companies involved it seems extremely unclear as to what they do or what products they actually sell.

After some consideration, and putting the tin foil hat to one side for a moment, it appears to me that these companies are part of what's known as the "black economy" or "security/industrial complex" - that is, a secret largely government funded part of the economy which is neither known about nor regulated by the general public.

If I knew more about the products being developed I might be more sympathetic to the idea of joining such an organisation. If for example a company wants to use computer vision to check which cars are in their carpark I'd have no particular objections to doing that, but I'm very keen not to get involved with anything which might bring me into disrepute, or be regarded by myself or by my peers as being an unethical use of technology. Also, I'd regard any restrictions upon my ability to talk freely about technical matters - above and beyond the normal level of business confidentiality which is to be expected - as completely unacceptable.

So I wouldn't be well suited to doing secret work for secret organisations, since at heart I'm an open source developer and I'm really useless at keeping secrets. If someone asks me a question - especially a technical question - I generally tend to try to answer it as honestly as possible. Also I have very little nationalist instinct, so appealing to notions of national identity absolutely doesn't work with me, and indeed most of the development which I've done in the past has been very international in nature.

Another sham inquiry

2009-06-15T15:02:00.000-07:00

With the Iraq war now more or less over, at least as far as Britain is concerned, it looks like there will be yet another sham inquiry to examine the whole affair - or at least go through the motions of pretending to examine it.

"It will start next month and take at least a year, Mr Brown said. It will not aim to 'apportion blame', he added."

Almost certainly this will follow the same pattern as the earlier Hutton and Butler inquiries, where the role of politicians will not be permitted to be scrutinized in any depth and nobody will really be held to account for what must probably rank as the most cynical war fought within my lifetime.

My predictions for this inquiry are as follows:

None of the critical information will be examined, such as the role of Tony Blair and his closest advisors circa 2002/3 in the decision to go to war.

The objections of the intelligence services during the preparation of the 2002 dossier "Iraq's weapons of Mass Destruction" will likely be either ignored or omitted due to "national security" reasons. The role of David Kelly, who tried to alert the media (via a BBC reporter) to the problem of evidence being distorted or fabricated, I think will be skipped over "because this matter was addressed in a previous inquiry".

There will either be no investigation, or only a cursory mention, of the "dodgy dossier" because this would make certain civil service departments look either foolish or dishonest.

There will be no examination of any correspondence between Tony Blair and George Bush in the months preceding the outbreak of war.

The inquiry will focus primarily on relatively low level details of the prosecution of the war, such as the issuing of soldier's equipment (bullet proof vests, boots, etc) and whether or not a sufficient number of helicopters were available to evacuate casualties. These aspects tend to obsess the popular press, because they involve stories of individual tragedy or heroism, and provide a substantial distraction from the higher level decision making at the political level.