class demo 1
Contents
init
clear
close all
read image
img = imread('test2.png');
imshow(img);
size(img)
ans =
120 360 3
sample the values
w = 30;
N = 12;
val = zeros([N 1]);
for k = 1:N
r = 60;
c = (k-1)*w + w/2;
z = img(r,c,:);
z(:);
val(k) = z(1);
end
val
val =
0
21
42
63
85
106
127
148
170
191
212
233
convert to grayscale
g = rgb2gray(img);
imshow(g);
sample values
val3 = zeros([N 1]);
for k = 1:N
r = 60;
c = (k-1)*w + w/2;
z = g(r,c,:);
z(:)
val3(k) = z(1);
end
plot(val,val3);
ans =
0
ans =
21
ans =
42
ans =
63
ans =
85
ans =
106
ans =
127
ans =
148
ans =
170
ans =
191
ans =
212
ans =
233
read image
img = imread('gray.png');
imshow(img);
size(img)
ans =
120 360
sample the values
w = 30;
N = 12;
val2 = zeros([N 1]);
for k = 1:N
r = 60;
c = (k-1)*w + w/2;
z = img(r,c,:);
z(:);
val2(k) = z(1);
end
val2
val2 =
0
2
6
13
23
37
54
75
103
133
168
208
plot(val,val2);
xlabel('old values');
ylabel('new values');
