diff --git a/src/extras/ImageUtils.js b/src/extras/ImageUtils.js
index dd471f199f832159643fc705452c3cb1eebee85c..1ecd715ab2dc8ba39aee02a0e1e8e24b04a693e6 100644
--- a/src/extras/ImageUtils.js
+++ b/src/extras/ImageUtils.js
@@ -86,12 +86,12 @@ THREE.ImageUtils = {
 
 		for ( var x = 0; x < width; x ++ ) {
 
-			for ( var y = 1; y < height; y ++ ) {
+			for ( var y = 0; y < height; y ++ ) {
 
-				var ly = y - 1 < 0 ? height - 1 : y - 1;
-				var uy = ( y + 1 ) % height;
-				var lx = x - 1 < 0 ? width - 1 : x - 1;
-				var ux = ( x + 1 ) % width;
+				var ly = y - 1 < 0 ? 0 : y - 1;
+				var uy = y + 1 > height - 1 ? height - 1 : y + 1;
+				var lx = x - 1 < 0 ? 0 : x - 1;
+				var ux = x + 1 > width - 1 ? width - 1 : x + 1;
 
 				var points = [];
 				var origin = [ 0, 0, data[ ( y * width + x ) * 4 ] / 255 * depth ];