What are Color Gamut? Everything you need to know about REC.709, REC.2020 & DCI

CIE 1931 xy chromaticity diagram showing the gamut of the sRGB color space (the triangle). The outer curved boundary is the spectral (or monochromatic) locus, with wavelengths shown in nanometers (labeled in blue).

色彩空間 (Color Space) 和色域 (Color Gamut) 意思一樣嗎？ 色彩空間是一個可識別、可量化且固定的顏色和亮度值光譜，適用於各種應用，包括電視廣播和影像編輯；而 色域指的是螢幕上可以再現的色彩範圍。

In other words, displays can only output a fraction of all visible colors. sRGB, the most common display color gamut in use today, is highlighted in the following diagram.

Let’s take a look at the three most popular ones. The most common standard for consumer computer displays is sRGB. It covers approximately 35% of all visible colors, making it a somewhat basic color gamut.

sRGB is the most standard used color gamut in digital products, Windows environments and monitors. The advantage of this color gamut is there are reduced discrepancies in color between input and output based on the narrow range.

sRGB還定義了原色強度與實際儲存的數值之間的非線性變換。 這個曲線類似於CRT顯示器的gamma回應。 重現這條曲線要比sRGB圖像在顯示器上正確顯示更加重要。 這個非線性變換意味著sRGB非常高效地使圖檔中的整數值表示了人眼可以分辨的顏色。