What happen when you substract two rows?

[burita]

Hello,
I'm a java JEE develloper and I'm having quite some trouble understanding
this piece of code :

img=imread(“test.jpg”);
c=0;
for i=img
   for j=1:rows(i)-1
      c+=uint64(abs(i(j)-i(j+1)));
   endfor
endfor
c

img is a 3 dimensional array MxNx3Color, each color goes from 1 to 255
what I don't understand is this : i(j)-i(j+1)
It does image row n - imagne row n+1

but what happens when you substract 2 rows? 
for example with two 3 dimension row :

row1 : |[125, 128, 255] [055, 011, 200] [078, 200, 159]]
row2 : |[225, 144, 111] [120, 128, 050] [123, 122, 111]]

what does row1 - row2 produce?
Thanks



--
View this message in context: 
http://octave.1599824.n4.nabble.com/What-happen-when-you-substract-two-rows-tp4665271.html
Sent from the Octave - General mailing list archive at Nabble.com.