Updating the contrast value (#1780)

* Updating the contrast value * Rain's suggested wording * removing the SRGB reference @michaelc does this work for removing a bib entry? * Meeting updates. * Aligned understandings docs From AWK comment.
w3c · Feb 22, 2022 · 826762c · 826762c
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diff --git a/biblio.js b/biblio.js
@@ -31,18 +31,6 @@ respecConfig.localBiblio = {
         "publisher": "International Standards Organization"
     },
 
-      	"sRGB": {
-      		"authors": [
-      			"M. Stokes",
-      			"M. Anderson",
-      			"S. Chandrasekar",
-      			"R. Motta"
-      		],
-      		"date": "November 5, 1996",
-      		"href": "https://www.w3.org/Graphics/Color/sRGB.html",
-      		"title": "A Standard Default Color Space for the Internet - sRGB, Version 1.10"
-      	},
-
       	"UNESCO": {
       		"date": "1997",
       		"href": "http://www.unesco.org/education/information/nfsunesco/doc/isced_1997.htm",

diff --git a/guidelines/terms/20/relative-luminance.html b/guidelines/terms/20/relative-luminance.html
@@ -12,13 +12,13 @@
 
    <ul>
 
-      <li>if RsRGB &lt;= 0.03928 then <strong>R</strong> = RsRGB/12.92 else <strong>R</strong> = ((RsRGB+0.055)/1.055) ^ 2.4
+      <li>if RsRGB &lt;= 0.04045 then <strong>R</strong> = RsRGB/12.92 else <strong>R</strong> = ((RsRGB+0.055)/1.055) ^ 2.4
       </li>
 
-      <li>if GsRGB &lt;= 0.03928 then <strong>G</strong> = GsRGB/12.92 else <strong>G</strong> = ((GsRGB+0.055)/1.055) ^ 2.4
+      <li>if GsRGB &lt;= 0.04045 then <strong>G</strong> = GsRGB/12.92 else <strong>G</strong> = ((GsRGB+0.055)/1.055) ^ 2.4
       </li>
 
-      <li>if BsRGB &lt;= 0.03928 then <strong>B</strong> = BsRGB/12.92 else <strong>B</strong> = ((BsRGB+0.055)/1.055) ^ 2.4
+      <li>if BsRGB &lt;= 0.04045 then <strong>B</strong> = BsRGB/12.92 else <strong>B</strong> = ((BsRGB+0.055)/1.055) ^ 2.4
       </li>
 
    </ul>
@@ -35,11 +35,13 @@
 
    </ul>
 
-   <p>The "^" character is the exponentiation operator. (Formula taken from [[sRGB]] and
+   <p>The "^" character is the exponentiation operator. (Formula taken from 
       [[IEC-4WD]]).
    </p>
 
   </div>
+
+  <p class="note">Before May 2021 the value of 0.04045 in the definition was different (0.03928). It was taken from an older version of the specification and has been updated. It has no practical effect on the calculations in the context of these guidelines.</p>
 
    <p class="note">Almost all systems used today to view Web content assume sRGB encoding. Unless it
       is known that another color space will be used to process and display the content,

diff --git a/techniques/general/G145.html b/techniques/general/G145.html
@@ -52,7 +52,7 @@
                      <ul>
                         <li>if R
                           sRGB
-                          &lt;= 0.03928 then
+                          &lt;= 0.04045 then
                           <strong>R</strong>
                           = R
                           sRGB
@@ -63,7 +63,7 @@
                           +0.055)/1.055) ^ 2.4</li>
                         <li>if G
                           sRGB
-                          &lt;= 0.03928 then
+                          &lt;= 0.04045 then
                           <strong>G</strong>
                           = G
                           sRGB
@@ -74,7 +74,7 @@
                           +0.055)/1.055) ^ 2.4</li>
                         <li>if B
                           sRGB
-                          &lt;= 0.03928 then
+                          &lt;= 0.04045 then
                           <strong>B</strong>
                           = B
                           sRGB
@@ -146,6 +146,7 @@
             <li>#4 is true</li>
          </ul>
       </section>
+      <p class="note">Before May 2021 the value of 0.04045 in the definition was different (0.03928). It was taken from an older version of the specification and has been updated. It has no practical effect on the calculations in the context of these guidelines.</p>
    </section><section id="related"><h2>Related Techniques</h2></section><section id="resources"><h2>Resources</h2>
 
          <ul>

diff --git a/techniques/general/G17.html b/techniques/general/G17.html
@@ -53,7 +53,7 @@
                      <ul>
                         <li>if R
                           sRGB
-                          &lt;= 0.03928 then
+                          &lt;= 0.04045 then
                           <strong>R</strong>
                           = R
                           sRGB
@@ -64,7 +64,7 @@
                           +0.055)/1.055) ^ 2.4</li>
                         <li>if G
                           sRGB
-                          &lt;= 0.03928 then
+                          &lt;= 0.04045 then
                           <strong>G</strong>
                           = G
                           sRGB
@@ -75,7 +75,7 @@
                           +0.055)/1.055) ^ 2.4</li>
                         <li>if B
                           sRGB
-                          &lt;= 0.03928 then
+                          &lt;= 0.04045 then
                           <strong>B</strong>
                           = B
                           sRGB
@@ -147,6 +147,7 @@
             <li>#4 is true</li>
          </ul>
       </section>
+      <p class="note">Before May 2021 the value of 0.04045 in the definition was different (0.03928). It was taken from an older version of the specification and has been updated. It has no practical effect on the calculations in the context of these guidelines.</p>
    </section><section id="related"><h2>Related Techniques</h2><ul>
       <li><a href="../general/G148">G148</a></li>
       <li><a href="../general/G174">G174</a></li>

diff --git a/techniques/general/G18.html b/techniques/general/G18.html
@@ -58,7 +58,7 @@
                      <ul>
                         <li>if R
                           sRGB
-                          &lt;= 0.03928 then
+                          &lt;= 0.04045 then
                           <strong>R</strong>
                           = R
                           sRGB
@@ -69,7 +69,7 @@
                           +0.055)/1.055) ^ 2.4</li>
                         <li>if G
                           sRGB
-                          &lt;= 0.03928 then
+                          &lt;= 0.04045 then
                           <strong>G</strong>
                           = G
                           sRGB
@@ -80,7 +80,7 @@
                           +0.055)/1.055) ^ 2.4</li>
                         <li>if B
                           sRGB
-                          &lt;= 0.03928 then
+                          &lt;= 0.04045 then
                           <strong>B</strong>
                           = B
                           sRGB
@@ -152,6 +152,7 @@
             <li>#4 is true.</li>
          </ul>
       </section>
+      <p class="note">Before May 2021 the value of 0.04045 in the definition was different (0.03928). It was taken from an older version of the specification and has been updated. It has no practical effect on the calculations in the context of these guidelines.</p>
    </section><section id="related"><h2>Related Techniques</h2></section><section id="resources"><h2>Resources</h2>
 
          <ul>

diff --git a/understanding/20/contrast-enhanced.html b/understanding/20/contrast-enhanced.html
@@ -163,13 +163,13 @@ <h3>Rationale for the Ratios Chosen</h3>
 
          <h3>Notes on formula</h3>
 
-         <p>Conversion from nonlinear to linear RGB values is based on IEC/4WD 61966-2-1 [[IEC-4WD]] and on "A Standard Default Color Space for the Internet - sRGB" [[sRGB]].</p>
+         <p>Conversion from nonlinear to linear RGB values is based on IEC/4WD 61966-2-1 [[IEC-4WD]].</p>
 
          <p>The formula (L1/L2) for contrast is based on [[ISO-9241-3]] and [[ANSI-HFES-100-1988]] standards.</p>
 
          <p>The ANSI/HFS 100-1988 standard calls for the contribution from ambient light to be
             included in the calculation of L1 and L2. The .05 value used is based on Typical Viewing
-            Flare from [[IEC-4WD]] and the [[sRGB]] paper by M. Stokes et al.
+            Flare from [[IEC-4WD]].
          </p>
 
          <p>This Success Criterion and its definitions use the terms "contrast ratio" and "relative

diff --git a/understanding/20/contrast-minimum.html b/understanding/20/contrast-minimum.html
@@ -223,13 +223,13 @@ <h3>Rationale for the Ratios Chosen</h3>
 
          <h3>Notes on formula</h3>
 
-         <p>Conversion from nonlinear to linear RGB values is based on IEC/4WD 61966-2-1 [[IEC-4WD]] and on "A Standard Default Color Space for the Internet - sRGB" [[sRGB]].</p>
+         <p>Conversion from nonlinear to linear RGB values is based on IEC/4WD 61966-2-1 [[IEC-4WD]].</p>
 
          <p>The formula (L1/L2) for contrast is based on [[ISO-9241-3]] and [[ANSI-HFES-100-1988]] standards.</p>
 
          <p>The ANSI/HFS 100-1988 standard calls for the contribution from ambient light to be
             included in the calculation of L1 and L2. The .05 value used is based on Typical Viewing
-            Flare from [[IEC-4WD]] and the [[sRGB]] paper by M. Stokes et al.
+            Flare from [[IEC-4WD]].
          </p>
 
          <p>This Success Criterion and its definitions use the terms "contrast ratio" and "relative