expose computeGradient in MATLAB class as hidden function
expose computeGradient in MATLAB class as hidden function

CVML/mexopencv,fengzhyuan/mexopencv,nanit/mexopencv,bearpaw/mexopencv,CVML/mexopencv,bearpaw/mexopencv,fengzhyuan/mexopencv,nanit/mexopencv