03 July 2012

Why Referendums?

UK Prime Minister David Cameron has raised again the possibility of a referendum on Britain's membership of the European Union (EU), but this begs the question: should we ever have a referendum on anything? Britain, in common with most western governements, is a representive democracy, that is people get the right to vote for people to run the country on their behalf - we are not a direct democracy, nor should we be.

Britain leaving the EU could have disastrous effects on our economy - or it might even be beneficial. I do not know, and I am sure that 99.9% of the population do not know either. Asking the general population their views on complex issues like this is madness, not least because voters will expect our elected officers to sort out the mess if it goes wrong. Whatever people think of govenment decisions, the people making them have to justify and implement them, and then deal with the consequences of their actions.

Thankfully referendums in Britain are rare - the last one we we had was on whether to adopt the Alternative Vote (AV) in general elections. The whole process was a shambles, not least because there is no rational argument against the adoption of AV, if you you accept that voting systems should be fair. The No Campaign was led by the Conservative Party, who knew full well that the current system was ludicrously unfair, but that crucially it favoured them. (Why some people in the Labour Part supported the No Campaign remains a mystery.)

In a general election we elect people to run the country for us - the goverment has an army of civil servants and others, to provide then with expert advice to guide them in their decisions. They should get on with the job and not ask the rest of us to make decisions for them.

29 June 2012

Photographic Reality

When people see a post-processed picture after using software such as Adobe Photoshop, or an HDR picture where tone mapping [1] has been used, a frequent comment is that they do not think the picture looks realistic - this begs the question of what people mean by realistic in this context. I believe that when people see a heavily post-processed picture they consider to be unrealistic, what they really mean is it does not look like a normal photograph.

Before the invention of photography, the only time people would see representations of scenes was in paintings and drawings. Landscape paintings by artists such as Constable do not look much like modern photographs of similar scenes. Interestingly when people see a tone-mapped high dynamic range picture they often say that it looks more like a painting than a photograph.

Superficially the human eye is similar to a camera in that it has a lens that focuses on a sensor, and it has aperture control and automatic focusing. However there are major differences: essentially a camera takes a snapshot with one focus setting and one aperture, and is a freeze of the picture taken in a fraction of a second. Conversely the brain/eye combination is more like a movie camera in that the eye is continuously scanning the image and the brain is composing a picture, so over a short period the aperture and focus are changing. Another significant difference is that we have two eyes, so depth perception is much better because of 3-D vision. Although 3-D cameras are available they are unlikely to become mainstream any time soon because a special viewer is need to see 3-D pictures.

When people have taken photographs in bright light conditions with dark shadows, they are often disappointed with the results, as often they do not think they represents what they actually saw at the time. The main reason for this is that human vision has a much greater dynamic range that that available on most modern cameras.

Dynamic range (or contrast ratio) is often measured by ratios such as 1:100,000. That is the brightest part of the picture is 100,000 times brighter than the darkest part of the picture. The darkest part is defined as the darkest colour above pure black that can be represented. These ratios can be difficult to understand, and I think it's better to use EV (Exposure Value) terminology, which is commonly used in photography. An increase of one EV is a doubling of the light received. Modern cameras can capture up to about 8 EVs if the picture is stored as a JPEG. In raw mode (usually only available on SLRs) more can theoretically be captured, but in practice most cameras cannot do more than about 12 EVs. Note that the dynamic range is more a function of the sensor than the bit depth. How human vision actually works is not well understood, but it is believed that the eye can capture at least 14 EVs. The fact that modern consumer technology cannot achieve the dynamic range of the eye is one of the reasons for many disappointing photographs. A modern display screen/display adapter can represent about 8 EVs, although in practice it is usually lower than that on LCD displays because of the backlight, which tends to turn black into dark grey. It is possible to get displays that represent about 17 EVs, but they are extremely expensive (around $50,000), so these are only really used in specialist applications like medical imaging. The situation is even worse when you try to print pictures, as it is very difficult to get printed material that contains much more than about 6 EVs.

Even if you take high dynamic range pictures using techniques such as overlaying multiple pictures taken at different EV levels (HDR), you still need to represent these on paper or an ordinary display. The standard way of doing this is to use tone-mapping, which essentially is a non-linear transformation of the large dynamic range back down to around 8 EVs. Generally when people refer to an HDR picture, what they are really are looking at is a tone-mapped version of the picture.

When JPEG (but not Raw) is the saved format, all cameras do some post-processing of the picture to produce a more balanced image. A gamma curve [5] is typically applied to produce a picture which is closer to normal human perception. Some cameras have optional facilities to lighten dark areas [6] and increasingly cameras are becoming available with simple built-in HDR processing [7].

I believe that tone-mapping is essentially what the eye/brain combination is doing, and also what landscape painters are doing naturally. I would contend that a realistic [2] tone-mapped version of a picture is probably a more accurate representation of a scene than a straight photograph. Note that not all scenes need a high dynamic range – on an overcast day a conventional picture is fine. But in bright sunshine I suspect that users will increasingly expect their camera to be able to provide an accurate representation of the scene as they perceived it at the time.

The second picture here is a tone-mapped HDR from 5 original photos taken at -2, -1, 0, +1, +2 EVs, and post-processed using special software (PhotomatixPro). The first picture is the middle picture of the sequence, and is what you would get with a straight photograph. Because of the very dark areas and the bright sunlight in this shot, it is not possible to capture the full dynamic range with one shot on a conventional camera. Most of the first picture is either under or over-exposed. The use of tone mapping enabled me to produce an image that was much closer to what I observed at the time.

Additional Notes

  1. For more information on HDR and tone-mapping see:
  2. A realistic tone-mapped image is where tone-mapping software is used to try and create a representation of the picture as the photographer saw it at the time. Examples can be seen in this Flickr group:
  3. Tone-mapping can also be used to produce exaggerated effects similar to surrealist or impressionist painters. This is moving into the realms of photography as art, and away from realism. As with all art, some people like the results and some people do not – but it is possible to produce some dramatic pictures from what would have been a dull single photograph. Pictures of dilapidated buildings or old vehicles are popular topics for this treatment. Various HDR groups on Flickr show examples of this, such as this one:
  4. New display technologies currently being developed hold out the prospect of affordable displays with improved dynamic range. However there are many technical difficulties and progress is slow. In particular OLED displays do not have a backlight and so, in theory, should be able to display pure black, and a much better dynamic range:
  5. More information on Gamma Correction can be found here: http://en.wikipedia.org/wiki/Gamma_correction
  6. The Dynamic Range (DR) facility on Sony Alpha cameras is on example of this. This allows for the lightening of dark shadow areas to bring out more detail. For JPEGs this is done in camera, but if Raw format is used additional control is available using Sony’s supplied software. One advantage with this is that it is done with a single shot and so can be used when there is movement in the subject.
  7. Manufacturers are now building-in simple HDR facilities to some of their cameras. Pentax and Sony have several models that support HDR, but most manufacturers have at least one camera that supports HDR/tone-mapping. The iPhone 4S has an HDR facility. Generally with the in-camera facility you have little or no control over the final appearance, but it is much easier than creating several images and post-processing them.

Photographs are of the Cloister at Iford Manor, Wiltshire, UK.

27 August 2011

UK Immigration

The latest report from the UK Office of National Statistics (ONS) shows immigration figures for 2010 at much the same as 2009, but a 21% increase in net immigration because of a significant reduction in emigration. All the national papers covered this story, but the ones I looked at all misrepresented the data to a greater or lesser extent. This is the norm for newspapers I find, so I usually try to go back to the original data. Surprisingly, and despite the fact that it is a major story in all the newspapers, the data is difficult to find on the ONS web site. When you do find it, the figures show that immigration for the last seven years shows no overall trend. The actual figures in thousands are 589, 567, 596, 574, 590, 567, 575; the last two show an increase in 2010 over 2009 of 1.4%.

Unfortunately coverage of immigration in some newspapers is coloured by an unattractive xenophobic agenda, which invariably leads to widespread misrepresentation of the data. The Daily Express, for example, claimed the 21% increase was on immigration rather than net immigration. To be fair both the Express and the Mail quoted the correct figures in the bodies of their articles, but how many of their readers would have noticed this?

The Coalition may be regretting targetting a reduction in net immigration as they have no real control over emigration. I believe that in practice it will be difficult to make significant reductions in immigration levels because so many people have legitimate cases. The Government cannot do anything about EU immigration, so it is concentrating on capping non-EU immigration. Despite what many tabloid newspapers claim, immigration controls are very tight in the UK, and potential immigrants, who are not coming to study or for family reasons (for example marriage visas), have to show they have a job or can otherwise support themselves. It is likely that capping non-EU numbers will simply result in increased immigration from the EU.

05 January 2011

Adopting Modern Communication

With the growth of social networking, we now have a large and diverse range of tools for communication: at one end there are traditional methods such as face-to-face meetings, telephone calls, letters and memos, and at the other there is instant messaging, micro-blogging, and e-mail. Unfortunately the natural conservatism of most people means that it is hard to get buy-in to use modern social networking methods. A problem here is that if you propose to a group of, say, 10 people, a meeting using some form of online discussion, then one or two are likely to refuse to take part and suggest a conventional meeting instead. Even if a conventional meeting is agreed, an online calendar could be used to arrange it and distribute any papers, but I go to some meetings where our calendar system is not used; the reason usually given is that one or two attendees refuse to use it. This sort of minority rule is holding back the adoption of modern methods of communication in many organisations, although in some places it works because management make executive decisions that certain technologies have to be used.

The one (relatively) modern communication method with widespread acceptance is e-mail, and this can sometimes be a compromise solution, but as I have written elsewhere it is, in my opinion, an unsuitable tool for discussion.

The reason frequently given for refusing to take part in on-line discussions is that the person prefers to talk to others, either directly or by telephone. The implication here is that they feel that methods such as instant messaging are always inferior, however it is voice communication that is often unsatisfactory. Consider, for example, a simple telephone call where one person rings another with a question, or to make a proposal. Sometimes the recipient can respond adequately without needing any time to think, but all too often the receiver would like a minute or two to consider their reply, or even look something up. The social dynamics of a voice conversation, however, demand the the responder replies immediately, even if only to say “I’ll call you back”. Also if the intended recipient is not by the telephone, the conversation cannot even start, and if they are, it may not be convenient for them to stop what they are doing to enter into a conversation. Conventional meetings can have similar problems: unless there is a strong chairperson who can control the discussion (rare in my experience), it is usually necessary to jump in quickly if you want to respond to something, to have any chance of being heard.

Tools such as Skype allow a combination of text messaging, voice and even live video. The addition of voice to text messaging adds an immediacy to the discussion, but may not enhance its quality. Instant messaging does not imply instant replying, and I believe in general you get a higher quality of discussion when people are given the chance to think before they respond.

05 August 2010

Google Wave and Group Communication

I believe that a good social networking tool to facilitate group discussion could be very successful, but now that Google Wave has been abandoned we still seem to be some off having anything that meets this need. There are probably many reasons for the failure of Wave, but the first was the inept way it was launched. Group discussion tools have many applications, but the most obvious in the workplace is as an online alternative to the conventional office meeting. To be usable however, it is necessary for everyone to have access to the facility, as well as some familiarity with using it. Launching Wave by issuing invites to a few people who had expressed an interest, pretty much guaranteed that most early users would assess it and then put it on the back burner until such time as it could be used for real discussions. Early users did not correspond, for the most part, to any groups that actually wanted to talk to each other, and in particular this made it almost impossible to assess it for use in the workplace where the chances are that most people in a work group would not have access to the service. Eventually more invites became available but by then many of the early adopters had lost interest and had stopped monitoring the site.

Even if they had handled the launch better, Wave may not have succeeded as it probably had too many radical ideas to get widespread acceptance. The only system I have used which I think successfully addresses the closed group communication market is Yammer. It is specifically targetted at organisations, and access is controlled by membership (and an email account) of a domain. Although you can use it for free, to get administrator control of the domain you need to pay a fixed amount per user. Yammer is much less ambitious than Wave but what it does do works very well. A major limitation is that more general groupings (for example groups of people from several different organisations) would be very difficult, if not impossible, to set up in Yammer - Wave was better in this respect. There are other commercial systems (Basecamp for example), but in general they have trouble dealing with arbitrary groups of people across different organisations.

What would it take to produce a successful group communication tool? I would suggest the following:

  • It needs to come from somebody with a clear idea of the target market
  • That almost certainly means not Google - they are good at coming up with ideas but seem uninterested in listening to user feedback. If you do not buy into their vision they lose interest.
  • It needs to be free to use at least the basic facilities - Yammer's pricing model rules it out for most educational establishments and public bodies.
  • A way needs to be found to overcome the natural conservatism of some users: many non-IT people are reluctant to adopt new computer-based ways of working. The use of a computer-based discussion tool for group discussion typically requires 100% take up. If, for example, you have a project involving 10 people and 2 refuse to take part in the new technology, then it will not get used. In effect a conservative minority can often mean that new communication technology will not be used. Yammer appears to have been successful in companies where the management decided to both install it, and require their staff to use it: this is difficult or impossible for many organisations.
I have previously written about the inadequacies of email for discussions, and conventional office meetings have obvious limitations, but with the demise of Wave we seem to be no closer to getting a viable alternative.

08 May 2010

Voting Reform

In my last blog I said that in the UK only the votes of about 10% of the electorate actually matter as a result of our voting system. Now the election has happened we have no party with an overall majority, and the the subject of voting reform has come to the fore as the basic unfairness of the system has become clear to everyone. All the smaller parties know that without proportional representation they will always be grossly under-represented in parliament, and conversely the two largest parties know that the current system can deliver them absolute power with only minority support from the voters.

This election dramatically illustrates how unfair the current system is with the Liberal Democrats getting only 8.7% of the seats with 23.0% of the vote, whereas the Conservatives got 47.1% of the seats with only 36.1% of the vote. With these figures I find it hard to accept that our first-past-the-post system can even be counted as democratic. The Conservative share of the vote means that 63.9% of the voters voted against them, so their claim to have the right to rule is tenuous at best. The other parties have even less claim to rule alone: the voters have in effect voted for coalition.

Our voting system has two main faults: you can only vote for one candidate and this encourages tactical voting, or voting for a major party even though one of the minor parties may be the first preference (the "wasted vote" argument). Secondly the number of votes received nationally has a non-linear relationship to the number of seats won. A small percentage, such as UKIP's 3.1%, delivers no seats when it should have resulted in 20. The first problem can be fixed easily, without a radical change to the current system, by introducing single transferable voting (usually called the Alternative Vote System when applied to single member elections) to the existing constituencies. By allowing voters to place their preferences in order, the need for tactical voting would go and everyone could vote naturally without feeling that their vote was wasted if they did not put one of the two major parties as first choice. There is no real argument against the single transferable vote, and it should have been introduced a long time ago, but unfortunately it does not really address the non-linearity problem: only a proportional representation system can do that.

The Jenkins Commission produced a report in 1998 which recommended the Alternative Vote Plus (AV+) system which, although it is not fully proportional, still looks like a good compromise. It does seem that an increasing number of people accept the voting reform will happen - let us hope that it comes sooner rather than later.

13 April 2010

UK General Election 2010

It is general election time again and we have the usual blanket media coverage. The media, and in particular the political commentators, love elections and seem convinced that everyone else shares their enthusiasm. All the partys are busily trying to push what they hope will be vote winning policies, but sadly I don't think many voters trust any of the partys to deliver! Blair promised a referendum on electoral reform but it never happened (although the Lib Dems would definitely deliver on that one). The Conservatives are promising to reverse the planned increase in national insurance contributions, but I suspect that if elected they will say that economic situation is worse than they thought and they will not be able to do it after all.

The UK media is saturated with election coverage, all presumably to inform voters as to how they might use their vote. However I find it hard to get interested as I am one of the 60% effectively disenfranchised by our ludicrously unfair voting system, and am in a constituency which always returns the same party candidate. In the other constituencies only 60% will vote anyway, many of whom will have decided how they are going to vote before the election was called.
Basically around 10% of the electorate will decide who forms the next government.