demo3

Contents

initialize

clear
rgb = imread('birds1.jpg');
% rgb = im2double(rgb);
do_input = false;
if ~do_input
    load demo3;
end

imshow(rgb);

select pixel values

if do_input
    [c r p] = impixel(rgb);
else
    p = impixel(rgb,c,r);
end
disp(p),

    34   134     0
   248    47     1
    18    32   103
   130   208     8

show pixel locations

imshow(rgb);
hold on
plot(c,r,'wo');
for n=1:length(c)
    text(c(n)+10,r(n),sprintf('%d',n),'Color','w');
end
hold off
% publishes as black plot annotations - runs as white

instantiate distance tool

figure
imshow(rgb);
if do_input
    hd = imdistline;
    %save demo3 c r p point1 point2
else
    hd = imdistline(gca, pts(:,1), pts(:,2));
end

The Distance tool contains a structure of function handles, called an API, that can be used to retrieve distance information and control other aspects of Distance tool behavior.

api = iptgetapi(hd);
w = api.getDistance();
fprintf('distance %g pixels\n',w);
pts = api.getPosition();
if do_input
    save demo3 c r p pts
end

distance 177.341 pixels

Published with MATLAB® R2015a