colour-channels

x colour-channels

Colour Channels
(24 bit colour)

There are channels for each of the three primary colours - red green & blue . Each of these channels have 256 levels ranging from black to saturation - and when mixed gives the possibility of 16,777,216 distinct shades and colours - including black & white - and 254 shades of grey.

primary colour constant at 255 and is diluted to white by adding equal parts of the other two primary colours from 0 to 255
grey scale is equal parts of all three primary
colours from 0 to 255

single channel primary colours from 0 to 255
with other two channels held constant at zero

Anyone who has studied art may be puzzled by this as they will know "Red" - "Yellow" and "Blue" as being the primary colours. The difference being that with paints we are talking about pigment colour - the actual colour perceived - is due to what light is reflected and absorbed by the pigments and is a subtractive process. Whereas screen or projected images - light is being mixed directly as an additive process.
If you mix the three saturated primary colours equally you will get white. Do the same with primary pigments and the end result will be brown/grey.
Much the same applies to colour printing - which generally uses cyan yellow & magenta inks - (the exact compliments to the RGB primary colours). As with paints - printing is a subtractive process whereby the perceived colour - is again due to what light is reflected and absorbed by the ink pigments.
There are technical problems in achieving photographic quality colour graduation with just three colours - so you will usually find additional colour inks used by photo quality printers. Whilst it is theoretically possible to achieve near to black by mixing CMY inks - it is not very economic so black is added for the darker shades. This is known as CMYK - where K represents black. White "printing" being an absence of ink - and is therefore determined by the whiteness of the paper.

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All material and images presented in these pages are copyright (C) James Montague 2001, 2002, 2003, 2004. . All rights reserved. This site may be freely linked to but not duplicated or presented in any way without my written consent.
created 2nd April 2003

revised 1st April 2004

Colour Channels (24 bit colour) There are channels for each of the three primary colours - red green & blue . Each of these channels have 256 levels ranging from black to saturation - and when mixed gives the possibility of 16,777,216 distinct shades and colours - including black & white - and 254 shades of grey.
	primary colour constant at 255 and is diluted to white by adding equal parts of the other two primary colours from 0 to 255 grey scale is equal parts of all three primary colours from 0 to 255
	single channel primary colours from 0 to 255 with other two channels held constant at zero
Anyone who has studied art may be puzzled by this as they will know "Red" - "Yellow" and "Blue" as being the primary colours. The difference being that with paints we are talking about pigment colour - the actual colour perceived - is due to what light is reflected and absorbed by the pigments and is a subtractive process. Whereas screen or projected images - light is being mixed directly as an additive process. If you mix the three saturated primary colours equally you will get white. Do the same with primary pigments and the end result will be brown/grey. Much the same applies to colour printing - which generally uses cyan yellow & magenta inks - (the exact compliments to the RGB primary colours). As with paints - printing is a subtractive process whereby the perceived colour - is again due to what light is reflected and absorbed by the ink pigments. There are technical problems in achieving photographic quality colour graduation with just three colours - so you will usually find additional colour inks used by photo quality printers. Whilst it is theoretically possible to achieve near to black by mixing CMY inks - it is not very economic so black is added for the darker shades. This is known as CMYK - where K represents black. White "printing" being an absence of ink - and is therefore determined by the whiteness of the paper.

Colour Channels (24 bit colour)

Colour Channels
(24 bit colour)