colorspace: use normalization factor 58.37/48 for ST.428-1 gamma

sekrit-twc · Jun 30, 2023 · 9833300 · 9833300
1 parent f80b515
commit 9833300
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/src/zimg/colorspace/gamma.cpp b/src/zimg/colorspace/gamma.cpp
@@ -277,12 +277,12 @@ float st_2084_inverse_eotf(float x) noexcept
 
 float st_428_eotf(float x) noexcept
 {
-	return x < 0.0f ? 0.0f : zimg_x_powf(x, 2.6f);
+	return x < 0.0f ? 0.0f : 52.37f / 48.0f * zimg_x_powf(x, 2.6f);
 }
 
 float st_428_inverse_eotf(float x) noexcept
 {
-	return x < 0.0f ? 0.0f : zimg_x_powf(x, 1.0f / 2.6f);
+	return x < 0.0f ? 0.0f : zimg_x_powf(x * (48.0f / 52.37f), 1.0f / 2.6f);
 }
 
 // Applies a per-channel correction instead of the iterative method specified in Rec.2100.