Research - Presentation

There are various methods of presenting digital images for viewing, including printing, viewing on screen or projection.

The main element which can affect viewing of images is the perception of colour, the range and intensity of colour can be percieved differently by any individual and can also be distorted by different viewing media.

Colour management is a control used to manage the colour conversion between various devices such as scanners, printers, cameras,  tv screens monitors  or computer printers.

The main goal of colour management is to ensure a good match between these devices and to this end the ICC, International Colour Consortium, has defined a standard colour matching module.

However, this complex method is often sidestepped by calibrating to a common standard colour space such as sRGB,developed by HP and Microsoft in 1996 for use in monitors, printers and the internet.

This should allow for near exact colour matching between monitor and printer but in reality colours on screen can often appear stronger and more vibrant than those reproduced by a printer.

Following is some technical information to explain sRGB concept:

The sRGB gamut
sRGB defines the chromaticities of the red, green, and blue primaries, the colors where one of the three channels is nonzero and the other two are zero. The gamut of chromaticities that can be represented in sRGB is the color triangle defined by these primaries. As with any RGB color space, for non-negative values of R, G, and B it is not possible to represent colors outside this triangle, which is well inside the range of colors visible to a human.

Chromaticity	Red	Green	Blue	White point
x	0.6400	0.3000	0.1500	0.3127
y	0.3300	0.6000	0.0600	0.3290
z	0.0300	0.1000	0.7900	0.3583

On an sRGB display, each solid bar should look as bright as the surrounding striped dither.

sRGB also defines a nonlinear transformation between the intensity of these primaries and the actual number stored. The curve is similar to the gamma response of a CRT display. It is more important to replicate this curve than the primaries to get correct display of an sRGB image. This nonlinear conversion means that sRGB is a reasonably efficient use of the values in an integer-based image file to display human-discernible light levels.
sRGB is sometimes avoided by high-end print publishing professionals because its color gamut is not big enough, especially in the blue-green colors, to include all the colors that can be reproduced in CMYK printing.

CIE 1931 xy chromaticity diagram showing the gamut of the sRGB color space and location of the primaries. The D65 white point is shown in the center. The Planckian locus is shown with color temperatures labeled in kelvin. The outer curved boundary is the spectral (or monochromatic) locus, with wavelengths shown in nanometers (labeled in blue). Note that the colors in this displayed file are being specified using sRGB. Areas outside the triangle cannot be accurately colored because they are out of the gamut of sRGB therefore they have been interpreted. Also note how the D65 label is not an ideal 6500-kelvin blackbody because it is based on atmospheric filtered daylight.