The encyclopedia · Software & IT · Technical decision · 1996–1999
HP and Microsoft's sRGB made one color space the web's silent default
sRGB picked a single reference CRT color and gamma 2.2, so images with no profile looked right on every screen without extra data.
Hewlett-Packard · Microsoft
the move
By the 1990s, monitors produced brightness that was not linear with the input signal: a power law with an exponent around 2 to 3 that varied by CRT maker. Every vendor shipped a slightly different color space, so the same image could look different on every screen.
Attaching an ICC profile solved it for high-end users, but most files could not carry one and embedding one added overhead. HP and Microsoft proposed a single calibrated RGB space matched to the average CRT and a 2.2 gamma, and asked every OS and browser to assume it by default.
why it works
- Color profiles were accurate but heavy, and many image formats could not carry them at all, so a large class of users never had any profile.
- Most computer monitors, scanners and digital cameras are all native RGB devices, so one RGB space suited the whole chain.
- The space was set to the average CRT behavior and the PC video-card signal, meaning it matched what most hardware already did.
what transfers
When interoperability is blocked by overhead, remove the overhead: make one canonical value the default so the common case needs no extra data at all.
what came after
sRGB became IEC 61966-2-1 in 1999 and is now the assumed color space for images with no embedded profile. The W3C CSS3 color spec and the web's default color management depend on it, so unprofiled JPEGs and PNGs render consistently across browsers and displays.
references
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