Measuring maximum height of an object

Hello!

I am new to the Matlab, especially to a Image Processing Toolbox, so I was wandering maybe somebody could give a hand on one question. I am assigned for the project to calculate the shoe size from a given picture, so far I have written the code to threshold the picture and find boundaries. The part where I am stuck is to calculate the maximum height and width of the feet, as long as the problem remains because there are two objects on the photo - the feet itself and a white square to compare true size. There is the part of the code that I have:

I = imread('feet.jpg');

fn = imnoise (I, 'gaussian', 0, 0.05);

%imshow (fn);

%figure, imhist(fn);

Tn = graythresh (fn);

gn = im2bw(fn, Tn);

%figure, imshow(gn);

%Smooth the image and repeat

w = fspecial ('average', 5);

fa = imfilter (fn, w, 'replicate');

%figure, imshow(fa);

%figure, imhist(fa);

Ta = graythresh (fa);

ga = im2bw(fa, Ta);

%figure, imshow(ga);

[L, num] = bwlabel (ga, 4);

g = bwperim(ga, 4);

figure, imshow(g)

Could anyone help out with the methods to use furthermore?

There is a link of a picture--> http://postimg.org/image/qgcvi3lvx/ecbea924/

Thanks in advance,

Jekaterina

[agung pratama]

I have same problem like this and still can't neasure the height