Tom Chan: Week 6 Camera Technology, Resolution and Scale

[2] The human eye renders colours differently to how a camera captures colour. The human eye contains three separate types of colour receptors that respond to red, green or blue wavelengths.
[3] A digital camera is designed to capture and express colour in the same fashion a human eye does and this is usually done through a silicon-based image sensor array. Unfortunately silicon doesn’t perceive colour exactly the same way we do.
They are more sensitive to near infra-red wavelengths and poor at detecting light at the blue end of the spectrum.
[4] Therefore a variety of techniques are used to adjust and correct this perception. There is the expensive and difficult multi-sensor camera approach, utilizing three RGB colour components to create a full colour image.
The second technique is the widely used Bayer, single sensor cameras. However due to the techniques involved, the image quality can be poor as there can be a lot of colour crosstalk in the colour perception process.

[4] Currently, most web cameras usually come under the Bayer, single sensor camera technology. As a method of controlling the façade as internet camera technology becomes more numerous and abundant we can begin to explore manipulating not the actual camera technology, but exploiting the what the camera perceives.

[5] As internet camera technology is usually similar and cheap, it is possible to easily identify their issues and design to exploit the colour/shape sensor technology, thereby possibly hiding or distorting the image.

Possibly by viewing the internet camera as the ‘predator’ and the façade as ‘prey’ we can start using the principle of countershading to influence façade shape designs to conceal or distort the façade.

[5] This would mean exploiting an internet camera’s vantage point, whether that be from a cityside cam or google street view but from a fixed vantage point many optical illusions could be utilized for various effects. Michael Bach discusses the effect of the illusion of size constancy, especially when distance information is not available. We instantly deduce flat two dimensional renderings of objects as three dimensional such that through an image such as the view through an internet camera, the opportunity to exploit facades and create façade adjustments the opportunities are numerous.

[7] In the Artful Eye Ramachandrian talks about the relationship between depth perception and the role that shadows play in helping us determine the solidity and shape of objects. The visual system believes generally that there is only 1 single source of light, that the light comes from above like the sun and that objects are usually convex, that is, protruding. This is useful in determining the size, shape and depth of complex objects, when unfamiliar with that object.
Therefore when a series of shaded ‘eggs’ are produced, those with shading on the bottom side of the eggs are seen as convex, and those with shading on the top half are seen as concaved.
[8, 9] These are some visual tests done through the effect of shadow to change the three dimensional aspects of a façade.

[10] Felice Varini is an artist that predominantly does perspectival artwork. Using the rules of perspective and by exploiting the vantage point, Varini paints objects that seem to float in the air.

[13] As internet cameras are developing better technology and become practically omniscient in society, it becomes harder to affect change between camera and façade especially through colour (the relationship between viewer and viewee), however through the fixed vantage point of a web camera, the tool of illusion is still a viable option whether as a strategical tool or a whimsical aesthetic addition to the façade.


As a thought
Also due to the technology used in internet cameras, again as a way of controlling the image or façade in a way that exploits the disadvantages of the peering electronic eye, one could theoretically influence the design of a façade to appear outside of the internet camera’s visual perceptive range. During the brightest hours a building could literally disappear by reflecting light to near IR-range so that the internet camera fails to perceive and collect the light source, thus rendering the building imperceptible. However with the advent of the digital signal processing (DSP) camera and back light compensation (BLC), bright image areas and low light areas that could only be perceived by high-end cameras with digital back-light masking capabilities can now be processed quite easily by any camera with DSP compensation.


Bibliography
Bach, M and Poloschek, C 2006, Optical Illusions, Visual Neuroscience www.michaelbach.de/ot/index.html

Fraser, B 1996, Color, Adobe Magazine
www.adobe.com/products/adobemag/archive/pdfs/9611febf.pdf

Kruegle, H. 2007, CCTV Surveilannce: analog and digital video practices and technology, Elsevier Butterworth Heinemann, Amsterdam.

Ramachandrian, V. S. ‘2-D or not 2-D – that is the question’ in Gregory, R.L. Harris, J. and Heard P. (eds) 1995, The artful eye, Oxford University Press, Oxford, pp. 249-267.

http://www.quadibloc.com/other/cfaint.htm - Savard, J ‘Colour Filter Array Designs’

http://www.definitionmagazine.com/issue_pdfs/def32/sensors.pdf --Whalen, M. ‘Capturing Colour’.