Fix normalization in the Sobel calculation.

diff --git a/sobel.frag b/sobel.frag
index 9feab1ee6b26ba5c614fd5f0ad2cc920e31f58eb..c4dabd519712465a9d2a5495617ac9c1e2708c5b 100644 (file)
--- a/sobel.frag
+++ b/sobel.frag
@@ -47,4 +47,8 @@ void main()
 
        gradients.x = (top_right + 2.0f * right + bottom_right) - (top_left + 2.0f * left + bottom_left);
        gradients.y = (top_left + 2.0 * top + top_right) - (bottom_left + 2.0f * bottom + bottom_right);
+
+       // Normalize so that we have a normalized unit of intensity levels per pixel.
+       gradients.x *= 0.125;
+       gradients.y *= 0.125;
 }