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Fix some typos in contrast docs #216

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merged 2 commits into from
Sep 10, 2022
Merged

Fix some typos in contrast docs #216

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1aacb55
typo
xi Sep 10, 2022
1f7e930
Fix parens in Weber contrast docs
xi Sep 10, 2022
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8 changes: 4 additions & 4 deletions docs/contrast.md
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Expand Up @@ -67,7 +67,7 @@ It is commonly used in lighting design,
and also to examine small, sharp edged symbols and text
on larger, uniformly-colored backgrounds.

> WC = Y<sub>max</sub> - Y<sub>min</sub> / Y<sub>min</sub>
> WC = (Y<sub>max</sub> - Y<sub>min</sub>) / Y<sub>min</sub>

Any two colors can be used,
and this formula does not care which is the text color and which is the background.
Expand All @@ -85,7 +85,7 @@ Weber contrast is typically used with printed test charts
with positive polarity (black text, white background).
The formula thus can be expressed as:

> WC<sub>pp</sub> = Y<sub>background</sub> - Y<sub>text</sub> / Y<sub>text</sub>
> WC<sub>pp</sub> = (Y<sub>background</sub> - Y<sub>text</sub>) / Y<sub>text</sub>

Hwang and Peli used a modified Weber contrast for
tablet-based, negative polarity testing (white text on black background),
Expand All @@ -95,7 +95,7 @@ and wrote:

The formula for negative polarity is

> WC<sub>np</sub> = Y<sub>text</sub> - Y<sub>background</sub> / Y<sub>text</sub>
> WC<sub>np</sub> = (Y<sub>text</sub> - Y<sub>background</sub>) / Y<sub>text</sub>


## Michelson Contrast
Expand Down Expand Up @@ -209,7 +209,7 @@ _This value is much higher than that in the sRGB standard,
which puts white at 80 cd/m2 and black at 0.2cd/m2,
a relative luminance boost of 0.0025._

> WCAG21 = = (Y<sub>max</sub> + 0.05) / (Y<sub>min</sub> + 0.05)
> WCAG21 = (Y<sub>max</sub> + 0.05) / (Y<sub>min</sub> + 0.05)

Because of it's widespread use,
color.js provides this method, mainly to aid comparison.
Expand Down