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scotwllm
scotwllm
Inspiring
November 6, 2023
Answered

Photoshop's RGB to HSB calculation

  • November 6, 2023
  • 2 replies
  • 488 views

When I type RGB values or a hex code into Photoshop's color picker, it automatically calculates HSB values. What are the formulas used to calculate the H, S, and B values presented in the color picker tool?

 

Scott

    This topic has been closed for replies.
    Correct answer scotwllm

    H = IF(180/PI()*ATAN2(2*R-G-B,SQRT(3)*(G-B))<0,180/PI()*ATAN2(2*R-G-B,SQRT(3)*(G-B))+360,180/PI()*ATAN2(2*R-G-B,SQRT(3)*(G-B)))

    S=(Max(R,G,B)-Min(R,G,B))/Max(R,G,B)

    B=Max(R,G,B)/255

     

    2 replies

    scotwllm
    scotwllmAuthorCorrect answer
    Inspiring
    July 30, 2024

    H = IF(180/PI()*ATAN2(2*R-G-B,SQRT(3)*(G-B))<0,180/PI()*ATAN2(2*R-G-B,SQRT(3)*(G-B))+360,180/PI()*ATAN2(2*R-G-B,SQRT(3)*(G-B)))

    S=(Max(R,G,B)-Min(R,G,B))/Max(R,G,B)

    B=Max(R,G,B)/255

     

      Kevin Stohlmeyer
      Community Expert
      Kevin StohlmeyerCommunity Expert
      Community Expert
      November 7, 2023

      See this existing thread regarding RGB/HSB calculations:

      https://community.adobe.com/t5/photoshop-ecosystem-discussions/calculate-hue-from-rgb/td-p/12603371

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