diff --git a/ui/gl/gl_shader.cpp b/ui/gl/gl_shader.cpp
index aa37476..5e5d7f1 100644
--- a/ui/gl/gl_shader.cpp
+++ b/ui/gl/gl_shader.cpp
@@ -74,10 +74,16 @@ uniform sampler2D u_texture;
 uniform sampler2D v_texture;
 )",
 		.body = R"(
-	float y = texture2D(y_texture, v_texcoord).r;
+//	float y = texture2D(y_texture, v_texcoord).r;
+	float y = texture2D(y_texture, v_texcoord).r - 0.0625;
 	float u = texture2D(u_texture, v_texcoord).r - 0.5;
 	float v = texture2D(v_texture, v_texcoord).r - 0.5;
-	result = vec4(y + 1.403 * v, y - 0.344 * u - 0.714 * v, y + 1.77 * u, 1);
+//	result = vec4(y + 1.403 * v, y - 0.344 * u - 0.714 * v, y + 1.77 * u, 1);
+	result = vec4(
+		1.164 * y + 1.596 * v,
+		1.164 * y - 0.392 * u - 0.813 * v,
+		1.164 * y + 2.17 * u,
+		1.);
 )",
 	};
 }