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yuv2rgb: Broadcast Color Space to RGB Conversion

Mathematical Foundation of Video Color Encoding​

YUV separates luminance (Y) from chrominance (UV) components, enabling efficient video compression and broadcast transmission. The conversion to RGB applies a linear transformation optimized for human visual perception of brightness and color.

The mathematical transformation: RGB=MYUV→RGB⋅YUV\text{RGB} = M_{\text{YUV}\rightarrow\text{RGB}} \cdot \text{YUV}

Where the transformation matrix accounts for different broadcast standards (HDTV vs SDTV) with distinct luminance weighting coefficients.

Broadcast Standard Differences​

HDTV (Rec. 709) and SDTV (Rec. 601) use different RGB-to-luminance conversion coefficients. HDTV applies greater weight to green components, reflecting modern display characteristics. SDTV uses legacy coefficients optimized for CRT displays.

Technical specifications:

  • HDTV weights: R=0.2126, G=0.7152, B=0.0722
  • SDTV weights: R=0.299, G=0.587, B=0.114
  • Chrominance scaling: U and V components scaled for efficient transmission
ライブエディター
const fragment = () => {
      const yComponent = 0.5
      const uComponent = uv.x.sub(0.5).mul(0.5)
      const vComponent = uv.y.sub(0.5).mul(0.5)
      const yuvColor = vec3(yComponent, uComponent, vComponent)
      return vec4(yuv2rgb(yuvColor), 1)
}