Tuesday, March 26, 2013

Fish that spit

When Swiss-born ophthalmologist Dr. Edmund Landolt proposed a new type of symbol for testing visual acuity in 1888, he probably would never have dreamed that one day it would be used to help explain how fish are able to feed on insects.

But that is exactly what Dr. Shelby Temple at Bristol University (Bristol, UK), and a team at the University of Queensland and the University of Western Australia have done. They have modified Dr. Landolt's so-called "C test" to discover the resolving power of the eyes of a family of fish known as archerfish.

The archerfish themselves are rather unusual creatures. They have a special way of hunting for food that involves spitting jets of water at tiny aerial insects high above the water's surface. Because sound and smell do not cross the air-water interface, these fish must depend on their visual capabilities to find, identify and accurately spit at their prey.

To discover how visually acute such fish are, the researchers first trained them to spit at one of two letters -- an 'O' or a 'C' -- by rewarding them with food.  Then they showed them small versions of both letters together and recorded which letter they spat at.

"This modified Landolt C test works because the only difference between the two letters is the gap in the C, so in order to tell the difference and spit at the right target to get their reward the fish must be able to resolve the gap," says Dr. Temple.

To test the archerfish's resolving power, the size of the letters were decreased in steps. The scientists then compared the behavioral results from their experiments to the fishes' predicted acuity based on measurements of the photoreceptor density in their retinas.

The results, published in the journal Vision Research, show that archerfish are one of the most visually acute freshwater fish. They are able to resolve between 3.23 and 3.57 cycles per degree (0.155-0.140° of visual arc) with the part of their retina that looks up and forwards, which is not surprising given their interesting foraging strategy.

If Dr. Landolt were alive today, I'm sure he'd undoubtedly be amused to learn how his test had been repurposed, and impressed to see how effective it was at helping biological scientists such as Dr. Temple determine the visual acuity of animals other than human beings.

More information on the research is available on the Bristol University web site here. The researchers' technical paper "A comparison of behavioural (Landolt C) and anatomical estimates of visual acuity in archerfish (Toxotes chatareus)" is available here.

Wednesday, March 20, 2013

Dead fish

The "discarding" of fish by commercial fishermen is a term commonly used to describe the practice of throwing unwanted fish back into the sea -- usually dead.

Under the European Common Fisheries Policy (CFP) discards have historically taken place for three reasons. Firstly, fish are discarded if they are small and under the legal minimum size which fishermen are allowed to land for that species. Second, they are thrown back into the sea if a fisherman's annual quota for that species has already been reached, making it illegal to land it. Lastly, fish are dispensed with if they are of a species which has no commercial market value.

Thankfully, discarding fish will soon become a thing of the past after the UK Government secured a historic victory in Brussels to set firm dates to reform the EU Common Fisheries Policy and introduce a ban on the practice. Hence the wasteful practice of discarding edible fish stocks like herring and mackerel will end from January 2014. A ban for white fish stocks will begin in January 2016.

The legislation will undoubtedly save the lives of many thousands of fish. But what of the scavenging birds that follow the fishing vessels to help themselves to a free lunch? How will they be affected by the move?

That's exactly what Dr. Stephen C. Votier, an Associate Professor in Marine Ecology at the School of Marine Science and Engineering at Plymouth University  (Plymouth, UK) wanted to find out.  To do so, Dr. Votier and his team attached cameras and GPS systems to ten Northern Gannets (Morus bassanus) to provide a unique view of how the seabirds interacted with the fishing vessels.

Results from his research revealed that all the cameras on the birds captured images of large (>15m) boats, but not smaller vessels. Virtually all the vessels were trawlers, and the gannets were almost always accompanied by other scavenging birds. All the birds  exhibited an area-restricted search during foraging, but only 42 per cent of such searches were associated with the fishing vessels, indicating that the birds were still foraging naturally.

The research illustrates the fact that those vessels discarding fish provide an important source of food for foraging gannets, but that they will be able to adapt well if discards were to disappear altogether -- if there is sufficient food to meet their nutritional needs.

While Dr. Votier's research has provided a fascinating insight into the foraging habits of seabirds, his technique of equipping birds with cameras and GPS systems might also be used in the future to fight in the battle against illegal, unreported and unregulated fishing activity, which may still result in a significant amount of discards.


1. A Bird’s Eye View of Discard Reforms: Bird-Borne Cameras Reveal Seabird/Fishery Interactions

2. Historic day as Fisheries Ministers agree a date for discards ban

Related articles from Vision Systems Design that you might also find of interest.

1. Cameras and computers count fish

Researchers at the University of Western Australia (Perth, Australia) led by associate professor Euan Harvey have been awarded a three-year, $450,000 Australian Research Council Linkage grant to develop a vision-based computer algorithm to count and measure fish.

2. Fish processed by vision system

Engineers at the Icelandic firm Valka (Kópavogur, Iceland) have designed a vision-based cutting machine that can cut out pin bones from red fish, as well as trim and portion the fish into fish fillets.

3. A fish tale

To maximize profits, fish farmers are using a machine-vision system and smart software to sort good fish eggs from bad.

Tuesday, March 19, 2013

Pretty girls make graves

Forty years ago, I read an interesting science fiction story about a novel device worn on the top of the head that lit up when its wearer was in the presence of an individual that he or she found particularly attractive.

The device in question removed all of the ambiguity involved in determining whether individuals thought that strangers were particularly desirable, and the story delved into the social implications of doing so.

While it sounded rather far fetched at the time, this week, science fiction became a bit closer to science reality with the news that Fujitsu Laboratories (Kawasaki, Japan) has developed software that is capable of measuring an individual's pulse rate in real time by calculating variations in the brightness of their face.

The software, which captures and processes images from a built-in camera in a PC, smart phone or tablet, can measure a pulse rate simply by pointing the device at a person's face for as little as five seconds.

The system takes advantage of the fact that one of the characteristics of hemoglobin in blood is that it absorbs green light. So, after capturing a video of the face with the camera, the software uses the peaks in the brightness of the green component of the RGB images in the video frames from which to compute a pulse rate.

Naturally enough, the good folks at Fujitsu see the development of such a system as enabling individuals to use their own inexpensive camera-equipped devices to determine how healthy they are. And while that's all well and good, there are clearly other social implications.

It's a well known fact, for example, that a racing pulse is a sign of instant attraction. So it's quite possible that -- should such software be offered onto the open market -- it could be used by certain folks to determine how attractive others find them.

While that might seem to be a rather frivolous use of the technology, there could be some health implications here too. According to that bastion of editorial excellence, the UK Daily Mail, for example, researchers at the University of Valencia (Valencia, Spain) have shown that -- for men -- just five minutes spent alone with a beautiful stranger can cause so much stress it may be bad for the heart.

For that reason, men lucky enough to spend time in the company of beautiful ladies might be better off pointing their smart phones at themselves -- rather than at the ladies -- to determine the effects their socializing is having on their health.


1. Fujitsu Laboratories develops real-time pulse monitor using facial imaging

2. How a beautiful stranger will send a man’s stress hormones soaring

Wednesday, March 13, 2013

Every moment remembered

These days, most folks in the western world carry a smart-phone with them at all times, enabling them not only to talk and text, but to also capture images of their friends and family.

Many such people, of course, only haul out their smart-phones to take a snap when they feel that the picture that they are taking is important enough to justify doing so. But the folks at Memoto (Linköping, Sweden) believe that because of that, many important moments in an individual's life might well be lost.

To rectify the situation, the engineers there have developed a miniature 36 x 36 x 9 mm wearable camera that a captures images continuously, creating a visual log of the life of the user.

Memoto itself was founded by six Swedish serial entrepreneurs just last year. Martin Källström, formerly founder and CEO of blog search engine Twingly, came up with the concept of the Memoto camera. To develop it further, he recruited his friend Oskar Kalmaru, founder of an online video provider, as well as Björn Wesén, who was, at the time, a freelance electronic design engineer.

The Memoto GPS-enabled weatherproof camera they have created has no buttons. While a user is wearing it, it takes two timed geotagged photos a minute, enabling a user to immediately review when and where he or she was when the image was taken.

Now there are some who might regard such a device as only pandering to the needs of individuals who are egotistical enough to believe that every moment of their lives should be recorded for posterity.

On the other hand, such cameras might prove extremely useful in certain industrial or security applications. I'm sure that many companies, for example, would be only too delighted to attach such cameras to their employees, so they might track their activities on a daily basis. And the police could certainly use them to tag known offenders and capture a visual log of their activities to ensure that they weren’t involved in any nefarious businesses.

If you would like to purchase one of the wearable cameras -- which come in three colors - orange, graphite grey and arctic white -- they can now be pre-ordered at the company web site for the price of $279.00.

Personally, I wouldn't have much use for one, unless I wanted to capture hours of images of the PC screen in front of which I sit for most of the day writing news and features for Vision Systems Design.

Monday, March 11, 2013

Entrepreneurs matter

Many companies who design and develop vision systems are founded by engineers with an entrepreneurial spirit who want to carve out their own niche in life rather than working in a nine-to-five job for a larger organization.

Such individuals often have the unique ability to not only identify a specific requirement in the marketplace, but are also able to direct their teams of engineers to create systems to meet those needs as well.

But what happens to such organizations when their founder dies? According to new research from the Universities of Warwick and Bergen, the result is rather astonishing -- the death of a founding entrepreneur wipes out on average 60 percent of a firm’s sales and cuts jobs by around 17 percent.

The research, by Professor Sascha O. Becker at Warwick University (Coventry, UK) and Professor Hans K. Hvide at Bergen University (Bergen, Norway) has shed some light on exactly how much a founder-entrepreneur 'matters' in terms of influencing the performance of privately-owned businesses.

To reach their conclusion, the researchers analyzed firms' performance up to four years after the death of the founder-entrepreneur and found a long-lasting and significant negative impact. Although they didn't specifically look at companies in the vision systems design marketplace, from my own experience, there is no doubt that the conclusions that they reached are equally applicable.

As well as the striking effect on sales, companies whose entrepreneur dies have 20 per cent lower survival rates two years after the death, compared to similar firms where the entrepreneur remains alive.

Warwick University's Professor Becker said that while the researchers expected businesses that experienced the death of a founder-entrepreneur to have some kind of a dip in performance immediately after the death owing to the upheaval, they had anticipated that there would be a bounce-back.

However, even four years after the death of a company founder, most firms showed no sign of recovering and the negative effect on performance appeared to continue even further beyond that.

Professor Becker said that the results showed what a vital role such people played in maintaining productivity levels within a firm, but could only surmise as to why that might be so. 

While it could be because the founder was a fantastic sales-person who generated a disproportionately high level of sales, it could be due to their leadership, where the employees were inspired to perform to their best ability.

The researchers looked at various different types of firms to see how they were affected by founder-entrepreneur death. But they found no difference between results for family or non-family firms, urban or rural businesses, and no significant variation across sectors.

The level of education of the founder-entrepreneur also played a role in determining how badly the firms were affected -- those with the most highly educated founders experienced a bigger drop in performance after their death. The researchers also looked at whether ownership shares mattered. What they found was that the effect of the death of a 50-per-cent owner was roughly half that of the death of a majority owner.

In the vision industry, I'm pleased to say that there are some companies that have continued to succeed after their founders have passed away. In many cases, however, they were founded by individuals who recognized the need to entrust the responsibility of running their companies to younger equally entrepreneurially-inspired individuals long before they died.

Wednesday, March 6, 2013

The best of times

It was the best of times. It was the worst of times. Unfortunately, it was the latter that greeted me upon arriving in Orlando, Florida at the Automated Imaging Association's business conference.

Originally, I had not planned to attend the conference, delegating the task to our European Editor, David Wilson, whom I decided needed a week in the sun after a cruel English winter.

However, after Jeff Burnstein, the President of the Association, informed me that I was to be presented with the AIA's annual achievement award, my plans quickly changed. After booking my flight, I decided that, after the conference was over, I would treat my brother to visit Mickey and Minnie at Disneyland.

 Unfortunately, this was not to be. On the day before the conference, I received a telephone call from Dave who informed me that he had pulled a muscle in his chest and could not get out of bed. And, so, armed with 35 tablets of Vicodin, I disembarked from the airplane to reconnoiter the situation.

From then on, things went south. The "beautiful" International Palms Resort hotel in Florida was not that beautiful -- in fact there were cigarette burns on the carpets, the place was filthy, the shower in my room was broken and the elevators did not work properly. To add to this nightmare, I discovered my brother in great pain lying in bed unable to move. Needless to say, I immediately called for a doctor.

After about two hours, an elderly gentleman arrived with his assistant replete with a bag full of more drugs than my local pharmacy. After what seemed like an hour long exam, my brother was diagnosed with a cracked rib, given an injection of hydrocortisone and a prescription for Vicodin. Needless to say, my brother was somewhat incapacitated for the whole week.

To make matters worse, I only had four hours before accepting my award. After driving to the airport to re-register Dave's car, I drove back to the beautiful International Palms Resort hotel and picked up the prescription. Luckily, there was a pharmacy opposite the hotel. Unluckily, the pharmacist who ran the shop informed me that the doctor had forgotten to write the dosage on the script. After a few telephone calls, I was presented with a bill for $95 for forty-four of the wonderful white tablets.

After I delivered them, I drove the car to the conference to accept my award, only to find some very worried organizers wondering where I had spent most of the day. Only having had four hours sleep, I decided that, after checking on my patient, I would try to get an early night.

Like the rest of my plans, this was not to be. At about 10:15pm that night, two of the attendees at the conference (who must remain nameless) decided to surprise me with a bottle of Moet and Chandon. After sitting around the hotel's swimming pool talking for the next four hours, it was finally time for bed. Four hours later, I went back to attend the rest of the conference.

Needless to say, our European Editor and I never did get to greet any rodents in the Magic Kingdom.

Monday, March 4, 2013

Thermal crackdown in Slough

To exploit those individuals in the UK on low incomes who may not be able to afford to live in conventional lodgings, some unscrupulous home owners have converted their outbuildings into accommodation which they then rent out at low cost.

The problem with such dwellings -- known in the UK as “sheds with beds” -- is that they may not comply with UK building or fire safety regulations, and hence could represent a hazard to the hapless tenants who are forced to rent them due to their unfortunate circumstances.

Now, Slough Borough Council is set to become the first local authority in the UK to do something about the problem, with the help of thermal imaging technology. To assist it in its endeavors, the council has commissioned geographic imaging company Bluesky International (Coalville, UK)  to fly an airplane fitted with aerial imaging cameras over the whole borough at night, after which it will produce a thermal map of the town. Officers will then use the map to pin-point warm areas in outbuildings.

It is not known exactly how many sheds with beds there are in Slough, but estimates range from 700 to 3,000. The occupants are believed to be mostly single adults or childless couples with low incomes.

According to Ray Haslam, head of environmental services and resilience for Slough Borough Council, aerial photography is one of a range of tactics the council is using to crack down on the problem, and it hopes that evidence of heat in outbuildings will help it build a true picture of how many sheds are being lived in and where they are.

“We will be able to cross-check and see whether they have valid Energy Performance Certificates (EPCs) which are required by law for places where people live. If they don’t, we will be speaking to landlords and offering some advice and guidance, and enforcing the law if we need to. One option is to repeatedly fine a landlord for not having an EPC. The fine is £200 a day, making it very expensive for people to continue using the outbuilding,” he said.

Slough Borough Council is one of a handful of local authorities who have been granted extra money from the UK Government to help improve conditions in houses of multi occupancy (HMOs) and reduce the number of sheds being used as accommodation without permission.

Cracking down on the exploitation of individuals living in unsafe housing clearly has its merits. The problem is, of course, that the technology itself does nothing to address the real issue of the lack of affordable housing. If more of that had been created in the first instance, then the need for the flying thermal cameras would be unnecessary.