[kwlug-disc] ColourHug

unsolicited unsolicited at swiz.ca
Thu May 2 21:01:53 EDT 2013

There's no easy way to answer this except by deep dive.

In the mean time, see http://en.wikipedia.org/wiki/Color_profile

Agreed, it's much easier to explore / explain visually in person. (Let 
alone, creating such would be QUITE effort intensive.)

In essence, everything and everybody perceives and displays colour 
differently. e.g. Every human and device sees white differently. Let 
alone different intensities / brightness. And the human eye has the 
remarkable facility / adaptability to understand that white under 
fluorescent light is the same white as seen in direct sunlight, or 
direct projection vs reflection - such as monitor vs print.

Colour profiling provides a matrix to transform a given input or output 
to a commonly accepted definition of (a/) colour. Each device needs one 
to perceive or project the same colours as the same colours / intensity.

Without it, for example, a sunset picture appears with different hues to 
different people.

The hug, since it knows it's own profile / how it perceives colour, 
'scans' a monitor displaying a provided known colour image, and computes 
the matrix that transforms the displayed image into the known correct 

Creating a colour profile that you then tell the computer to use. So 
that you, the viewer, see an image colour corrected for the 
peculiarities of that particular monitor.

A long and exhaustive chain is involved here - the camera has a profile, 
the monitor has a profile, the printer has a profile, the image 
purchaser's monitor has a different profile ...

(And we haven't even touched on the concept of colour gamut, bleed, or 
resolution, nor the limitations of particular technologies. See 
http://en.wikipedia.org/wiki/LCD_panel to keep going.)

It is more than just a purist's issue, but that is not commonly 
recognized. (e.g. Various photo sites degrade images to some extent. 
Compression, .jpg vs .png vs .tif, software, 8-bit gimp vs 32-bit Raw 
Therapee, comes into play ...

... anyone know if there's a photography equivalent to kwlug in the area?

On 13-05-01 03:27 PM, Bob Jonkman wrote:
> What is this? What does it do? OK, colour profiles. What does that mean?
> How does it work? Why would I want you to profile my laptop?
> FAQs? We don't need no hughski FAQs! We need a presentation!

> On 13-05-01 01:15 PM, Chris Irwin wrote:
>> I had previously mentioned that I received a Colour Hug device for
>> creating colour profiles for displays, and that I would be bringing it
>> to a future meeting. If nobody remembers that, it's because it was
>> June 2012!
>> I will definitely be at the May meeting, and definitely have the
>> ColourHug device with me. And this time, I mean it! :)
>> If anybody wants to have a profile created for their laptop, I can run
>> a some on a first-come first-serve basis at the meeting, provided I
>> can set up at the back where I can hear the ZFS talk without
>> distracting Lori.
>> For more information about the ColorHug, check out the website. In
>> particular, read the FAQ if you're interested in having a profile
>> created.
>> ColourHug: http://hughski.com/
>> FAQ: http://hughski.com/faq.html

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