Assume that an input image has the following 6 x 6 pixels

3	4	4	4	5	5
4	7	3	1	1	3
2	8	4	7	0	2
5	2	3	8	1	7
6	1	2	3	2	6
7	4	5	5	3	4

And we have two filters, a vertical edge filter, F1, as

1	0	-1
1	0	-1
1	0	-1

And, a horizontal edge filter, F2:

1	1	1
0	0	0
-1	-1	-1

When the input image is convolved with the filter F1, we get the following 4 by 4 output (before any bias or activation function may apply):

a	b	c	d
e	f	g	h
i	j	k	l
m	n	o	p

a: b: c: d: e: f: g: h: i: j: k: l: m: n: o: p:

Now we use the horizontal filter, F2. Fill out the blanks for the values of the output:

a=

b=

c=

d=

e=

f=

g=

h=

i=

j=

k=

l=

m=

n=

o=

p=