casesandberg/react-color

Wrong Brightness Coefficients

Open

#184 opened on Jul 2, 2016

View on GitHub
 (11 comments) (0 reactions) (0 assignees)JavaScript (11,679 stars) (946 forks)batch import
bughelp wanted

Description

https://github.com/casesandberg/react-color/blob/master/modules/tinycolor2/index.js#L76

For now there are coefficients for NTSC, not sRGB. And i think that w3c is little bit outdated.

Also see this demo: http://codepen.io/dom1n1k/pen/LZWjbj

See sRGB table: http://www.brucelindbloom.com/index.html?WorkingSpaceInfo.html Or point 9 here: http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html

Contributor guide

Tech stack
javascript
Domain
frontend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
JavaScriptcolor theory basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
The issue points to wrong brightness coefficients in the tinycolor2 module at modules/tinycolor2/index.js line 76. The current coefficients are for NTSC, but should be sRGB coefficients. The user provides references to sRGB coefficients from Bruce Lindbloom and Poynton. To fix, replace the coefficient values in the luminance calculation with correct sRGB values. Ensure the change matches the expected output from the demo link. No linked PRs exist.