Category Archives: technology

The future of colour is quantum

news, technology, , ,

image-20150105-13827-1uj9moe

Although our digital displays can show literally millions of colours in fact they show us less than half of the possible colours in the world. This is partly because of the reliance on trichromatic devices – what you probably know as RGB. No matter how we choose them, it is impossible to mix together three colours and make all of the other colours. This is despite this embarrassing statement on the BBC website:

Red, yellow and blue are primary colours, which means they can’t be mixed using any other colours. In theory, all other colours can be mixed from these three colours.

This is just plain wrong. It is not the case that in theory, all other colours can be mixed from these three colours. In theory, and in practice, they cannot.

But I digress. The point is that using a three-colour primary system – a trichromatic system – is never going be able to reproduce all of the possible colours in the world. But even if we do use three, we could do better than the current TVs, phones and tablets on the market if we could improve our technology. The problem is that the red, green and blue lights in these displays are not as bright and colourful as they could be. That is where quantum dots come in.

Quantum dots are tiny crystals that can be precisely tuned to efficiently produce very specific colours. The crystals are grown from a mixture of various semiconductor materials and liquid solvents. By carefully controlling the conditions, engineers can adjust the size of the crystals, which determines the wavelength of the light that the crystals emit. Smaller quantum dots, with a diameter of two nanometres (two billionths of a metre) or so, emit short-wavelength, or blue, light. Bigger dots, with diameters closer to eight nanometres, produce light that’s nearer the long-wavelength, or red, end of the spectrum. We can expect to see new technology on the market soon offering brighter and more colourful displays.

green light may cure your headache

nature, news, technology, , ,

I get migraines. Not often. Just a few times each year. But when I get one I have been known to turn off the lights and go to sleep in my office. I have found that taking a pain killer and then going to sleep is the only way to relieve my symptoms. But a study in the journal Brain suggests that exposure to green light actually has a beneficial effect.

green

In the study 80 percent of subjects reported intensification of headache with exposure to high intensity of light, except green. Surprisingly, the researchers found that exposure to green light reduced pain 20 percent. They also found that the signals generated in the retina for green light are smaller than those signals generated for red and blue light. Researchers are now trying to develop a more affordable light bulb that emits pure narrow-band wavelength of green light and sunglasses that can block out all colours of light except narrow-band green light.

clothes that change colour

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Colour-shifting threads that change their hues in response to electrical charges are being developed as part of Google’s Project Jacquard. The technology still has a way to go before it could be in the shops but it gives the potential that your could change the colour of your clothes with the ‘flick of a switch’ rather than buying new ones or even that clothes could change colour with your mood. As if that would be a good thing.

For more see here.

measure colour with your smartphone

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node

This looks interesting. Node is a way to add sensors to your iOS device. It allows you to measure all sorts of things, including colour if you have the node+chroma combination. The node costs about £100 and the additional sensors cost about £50 each. I am not sure how much the chroma sensor costs.

You can find further details here – http://variableinc.com/chroma-contact/

accurate colour on a smartphone or tablet

advanced stuff, knowledge, opinions/rants, professional, technology, , , , , ,

Electronic displays can vary in their characteristics. Although almost all are based on RGB, in fact the RGB primaries in the display can vary greatly from one manufacturer to another. Colour management is the process of making adjustments to an image so that colour fidelity will be preserved. In conventional displays – desktops and laptops – the way this is achieved is through ICC colour profiles. Colour profiles store information about the colours on a particular device that are produced by RGB values on that device. So to make a display profile you normally need to display some colours on the screen and measure the CIE XYZ values of those colours; you then have the RGB values you used and the XYZ values that resulted. The profiling software can use these corresponding RGB and XYZ values to build a colour profile so that the colour management engine knows how to adjust the RGB values of an image so that the colours are displayed properly. Building a profile often requires specialist colour measurement equipment – though this can often be quite inexpensive now. If you are using your desktop or laptop display and you have never built a profile then you are probably using the default profile that was provided when your display was shipped. The default profile will ensure some level of colour fidelity but particular settings (such as the colour temperature or the gamma) may not be adequately accounted for. If you want accurate colour then you should learn about colour profiling.

It all sounds simple except for the fact that ICC colour profiles are not supported by iOS or Android operating systems on mobile devices. I find this really surprising but that’s how it is for now. Maybe it will be different in the future.

This means that ensuring colour fidelity on a smartphone or tablet is not so straight forward. So what can you do?

Well, there are two commercial solutions to this problem that I am aware of. They are X-rite’s ColorTrue and Datacolor’s SpyderGallery. ColorTrue and SpyderGallery are apps that will use a colour profile and provide good colour fidelity. These are great solutions. Perhaps the only drawback is that the colour correction only applies to images that are viewed from within the app. Having said that, they allow your standard photo album photos to be accessed – but the correction would not apply, for example, to images viewed using your web browser. This is why a proper system implemented at the level of the operating system would be better, in my opinion.

There are two alternatives. The first would be to implement your own colour correction and modify the images offline before sending them to the device. This would not suit everyone – the average consumer who just wanted to look at their photos for example. But it is what I typically do here in the lab if I want to display some accurate colour images on a tablet. But if you were a company and you wanted to display images of some products for example – it might be a reasonable approach. It has the advantage that the colour correction will work when viewed in any app on the device because the colour correction has been applied at the image level rather than the app level. But it does mean you need to do this separately for each device and keep track of which images are paired to each device. This is ok if you have one or a small number of devices but maybe not so good if you have hundreds of devices.

The second alternative would be to build your own app. If you want to do things with your images that you cannot do in ColorTrue or SpyderGallery or if you have lots of devices and you can’t be bothered to manually convert the images for each device, then you could install your own app that implements a colour profile and then does whatever else you want it to do.

curved displays are the future

design, news, professional, technology, , , ,

samsungevent

Yesterday I spoke an an event to launch Samsung’s latest curved screen displays. The technology is really gorgeous and everyone who attended was wanting one of the new displays after seeing them.

I am convinced that curved screens will become ever more popular in the future because not only do they look good but they offer serious advantages for users who undertake intensive tasks – the sort of tasks that need a large desktop display rather than a mobile device. When it comes to desktop displays it is really quite simple – bigger is better.

Many people – and I am one of them – are what is known as ‘double screeners’. I have two screens attached to my desktop and my operating system is spread seamlessly across them because I wanted more screen space to work in. I recently carried out a survey – you can find more details here – which showed that 38% of British office workers are already using two or more screens attached to their desktop computers.

Of course, in an ideal world one very large screen would be better than two smaller screens. But there is a problem with most flat-screen technology which is that the LED/LCD pixels emit light straight out but emit a lot less light at an angle to the screen. This means that you look at a large flat screen the light reaching your eye from the edges of the screen is a lot less. Not only that but, because you are looking at the screen at an angle, text and other fine details can be distorted at the edge. Curved displays get around this problem and I am hoping to replace my two flat screens soon with a single Samsung curved display.

With a curved display the distance from the eye to the screen is the same across the whole display and the angle of view is also constant. Not only does this solve the colour and acuity problems I just mentioned but it means that users need to need fewer eye and neck movements. Given that many of us spending longer using a display than we do actually sleeping this could have a big effect on user well-being.

Our survey also showed that about 60% of office workers think it is important that the office technology they use looks good. This can help to motivate them and help them to feel good about themselves. The new Samsung curved displays certainly will satisfy these people.

What colour is the sky on mars?

nature, news, technology, , , , , , ,

mars_originalmars_red

The cameras never lies. Or does it? Recently I had to take a photo for a medical case and before submitting it I had to sign to say that the photo had not been modified. I did this – but it was ridiculous of course. Many people have this idea that the cameras faithfully captures what the scene looks like and that, unless we intentionally manipulate the images (in photoshop, for example), then we have captured the truth. Nothing could be further from the truth – as the recent image of #TheDress showed.

The top photo above was taken and released by NASA in 1976 and shows a Martian landscape. The sky is blue. However, at the time, Carl Sagan said “Despite the impression on these images, the sky is not blue…The sky is in fact pink.”

You see the original image had not been colour corrected. Colour correction is a process that takes place on most cameras these days without the user being aware of it but in 1976 was not automatic. The process can compensate for the spectral sensitivities of the camera sensors (which may differ from one camera to another) or for the colour of the light source. The second picture (above) shows the colour-corrected image. Some people are now arguing, however, that the amount of colour correction applied by NASA is wrong and that the sky should not be as red as it appears on the second photograph. For the full story including some other nice images of Mars see here.

It couldn’t get much blacker

opinions/rants, technology, , ,

black
A few weeks ago I was taking my son to a birthday party and a journalist from The Independent phoned me to ask my opinion on Vantablack. This is the blackest material ever made. Whereas most black materials reflect about 4% of the light (or more) at all wavelengths, this new nano-material has really really low reflectance. It only reflects about 0.035% of the light. I gave a few comments and an article appeared in The Independent which was nice. I used to really like The Independent, back in the days when I read newspapers. The original article by Ian Johnston was very good imho.

However, a few days later the story was all around the world and I was often cited, all based on that one phone interview with Ian. The thing was that it was not even that big news. That is, yes, it is the blackest material ever made, but the truth is it is an incremental improvement in blackness beating the previous blackest material from a few years ago. My name even appeared in the Daily Mail. Most embarrassingly, I was interviewed on an American radio show. The reason I say it was embarrassing was that this new development actually had nothing to do with me and I didn’t want people thinking I was trying to claim credit. So when I agreed to do the radio show I told the researcher that they needed to be clear that this was nothing to do with me. I didn’t invent it. Imagine my surprise when John Hockenberry (that was his name, I believe) asked me, “So Dr Westland, what have you stumbled upon?”. Arghhhhh!!! Luckily, it was not a live interview because it actually got worse. A lot worse. So bad, that I could barely summon up strength to listen to it when it went out the next day. But actually, the editors did a good job and the final cut is not too bad. You can hear it here.

It would be nice to talk about my own work. I work in the area of blackness. One of the things I do is to ask people to rank different black samples in order of least black to most black. This allows me to discover, for example, that women prefer reddish blacks and men prefer bluish blacks. Also, asians prefer reddish blacks and caucasians prefer bluish blacks. I am developing a blackness index; a way to measure a sample and say how black it is or whether one sample is blacker than another. Why? Well, one application is for manufacturers of black ink for printers (which may be made from coloured inks). Different recipes produce different blacks. What if one recipe is chromatically neutral but another recipe is less neural (it has a slight hue) but is darker – which one is blacker?

grab colour – use it

design, news, opinions/rants, technology, , , , , , ,

colour pen

Many of you will have seen the Scribble Pen which uses a colour sensor to detect colours. The sensor is embedded at the end of the pen opposite the nib. The pen then mixes the required coloured ink (cyan, magenta, yellow, white and black) for drawing, using small refillable ink cartridges that fit inside its body. The device can hold 100,000 unique colours in its internal memory and can reproduce over 16 million unique colours.

But wait. Don’t think that means you will be able to use the pen to write in 16 million different colours. You won’t. A typical phone screen can display about 16 million unique combinations of RGB (red, green and blue). But many of the RGB combinations are indistinguishable. Open up powerpoint and make two squares. Set the RGB values of one to [10 220 10] and of the other to [10 220 11]. I would be amazed if you could really tell the difference between them. And anyone who has read much of my blog will know that I believe that if two colours look the same then they are the same. So the pen might be able to create 16 million combinations of cyan, magenta, yellow, white, and black – but that doesn’t mean 16 million different colours.

The second problem is that just because your pen can grab a colour (using its sensor) doesn’t mean it can create it. There are lots of colours out there in the world that are outside the colour gamut of an ink-based system (even one using five primaries – cyan, magenta, yellow, white and black).

Read more: http://www.dailymail.co.uk/sciencetech/article-2647129/Forget-crayons-Multicolour-pen-lets-pick-colour-draw-16-million-shades.html#ixzz35gJ0racJ
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