diff --git a/gradient.m b/gradient.m
index 511395bb47192ba8eed0cfb1c46e1ba3f24ca289..b1531998a64111bad0fd4886a8329278499ca8b1 100644
--- a/gradient.m
+++ b/gradient.m
@@ -4,11 +4,7 @@ function [datax,datay] = gradient(data)
 
 frames = LF.split(data);
 
-filtx = -fspecial('sobel') /8;
-filty = -fspecial('sobel')'/8;
-
-framesx = cellfun(@(f) imfilter(f,filtx),frames,'UniformOutput',false);
-framesy = cellfun(@(f) imfilter(f,filty),frames,'UniformOutput',false);
+[framesx,framesy] = cellfun(@gradient,frames,'UniformOutput',false);
 
 datax = LF.join(framesx);
 datay = LF.join(framesy);