function defgridi(t1,t2)
%displays deformed grid with displacements 
%given by matrices t1 and t2
%in matrix (image) coordinates
[l1,l2]=size(t1);xs=1:l1;ys=1:l2;
[Y,X]=meshgrid(ys,xs);
X=X+t1;Y=Y+t2;
Y1=Y;Y=l1-X+1;X=Y1;
clf
hold on
for x=1:l1-1
	for y=1:l2-1
		plot([X(x,y),X(x+1,y)],[Y(x,y),Y(x+1,y)]);
	end
end		
for x=1:l1-1
	for y=1:l2-1
		plot([X(x,y),X(x,y+1)],[Y(x,y),Y(x,y+1)]);	
	end
end