sRGB

SRGB color space or standard RGB (red -green-blue ) is a RGB color space.

Use

The color space was created through a collaboration between Hewlett -Packard and Microsoft Corporation and confirmed by the W3C, Exif, Intel, Pantone, Corel and many other industry participants. He is accepted as well in open source software like GIMP, and is applied in both proprietary and open graphics formats such as PNG.

Color definition

SRGB defined red, green and blue primaries as the color in such a way that one of the three channels can have its maximum value when the two others are zero. In CIE xy chromaticity red is [ 0.6400, 0.3300 ], green in [ 0.3000, 0.6000 ] and blue in [ 0.1500, 0.0600 ]. The white point is the D65 white point of [ 0.3127,0.3290 ]. All other valences are formed by the multiplication of the primaries with the values ​​and subsequent addition indicated in the graph. sRGB has been criticized for its awkward placement of the primaries. If we restrict the indices to the interval [ 0,1], it is impossible to represent colors outside of the gamut (the triangle shown in the graph), which are located within the amount of visible colors for humans. However, the values ​​of the primaries are less important than the luminance curve, so that an image can be reproduced as much as possible.

Criticism

SRGB was developed at the time for the CRT monitors of 1996. Many programs are based, therefore, on the assumption that an 8 -bit image file is displayed unchanged at a 8-Bit/Kanal-Display-Buffer. Therefore, one can assume that almost any image file is 8-bit per channel in sRGB. Also other hardware such as LCD screens and color printers, although they do not spend out of a sRGB curve, equipped with compensation circuits or software, so that they follow but at the end of the standard. However, this is not always professional hardware.

About suitable RGB color spaces is often discussed among users. sRGB is criticized partly because of its small gamut. Some visible from the eye colors that can be displayed for about CMYK, can not be represented here. Adobe RGB or ECI- RGB is therefore usually preferred by image processing experts.