[HN Gopher] How to make sense of ancient Greek colours (2020)
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       How to make sense of ancient Greek colours (2020)
        
       Author : benbreen
       Score  : 13 points
       Date   : 2022-06-17 20:12 UTC (2 hours ago)
        
 (HTM) web link (kiwihellenist.blogspot.com)
 (TXT) w3m dump (kiwihellenist.blogspot.com)
        
       | thaumasiotes wrote:
       | I'm a little uncomfortable with the author's insistence that hue,
       | saturation, and value are objective physical measurements:
       | 
       | > Outlined are the controls for three parameters which define the
       | physical parameters of any colour uniquely. 'Hue' for the part of
       | the spectrum the colour falls on; 'saturation' for the range from
       | grey to vivid; and 'value' for lightness-darkness.
       | 
       | > Hue, saturation, and value represent only the physical
       | characteristics of coloured light.
       | 
       | I don't think this is right. Hue, saturation, and value are
       | statements about human perception, not about the physical
       | characteristics of light. A description of the physical
       | characteristics of some light would look like a histogram
       | plotting the wavelength of the light against the amount of light
       | present at each wavelength. How do you interpret HSV from that?
       | 
       | Well, value is pretty straightforward: the greater the area
       | plotted in your histogram, the higher the value, I guess. More
       | light -> more value. This falls apart if we're considering light
       | of a single wavelength, where increasing the amount of light
       | doesn't cause the color to get more washed out.
       | 
       | Saturation is less straightforward, but the idea is there: a
       | color with low saturation (greyish) should have a histogram that
       | looks more or less flat, and a color with high saturation should
       | have a histogram characterized by a lot of zeroes and spikes. The
       | number of spikes in the histogram is... completely arbitrary.
       | 
       | Then we come to hue and our model completely falls apart. Hue is
       | purely subjective and there's no way to systematically relate it
       | to light wavelengths.
       | 
       | The article comes close to suggesting that hue is objectively
       | significant:
       | 
       | > In the colour circle at the left, the direction from the centre
       | represents hue
       | 
       | > Most English speakers would be comfortable using 'blue' to
       | refer to all of the top left quarter of the circle. But we
       | wouldn't feel nearly as comfortable grouping all of the bottom
       | right quarter under a single term.
       | 
       | This is true, but it's an artifact of an arbitrary definition of
       | hue. You could change how much angular space is assigned to each
       | color without causing any problems in the HSV model.
       | 
       | There's another interesting claim in the piece:
       | 
       | > Gladstone does make a starkly racist declaration that ancient
       | colour systems are 'less mature' than contemporary English.
       | 
       | It seems pretty likely that Gladstone would have been happy to
       | claim that he and the ancient Greeks belonged to the same race.
       | Why is this a starkly racist declaration?
        
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       (page generated 2022-06-17 23:01 UTC)