# How the user defined facefind function works here?

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Shaila parvin on 17 Feb 2014
Answered: vienthong10 tphcm on 25 Apr 2014
Hi everyone. Hope, all you are doing well. I am in a problem. Please help me out if possible. I’m so poor at matlab. I need a code that can detect faces in images. So I did google and got the code below:
EXAMPLE:
if (size(x,3)>1)%if RGB image make gray scale
try
x=rgb2gray(x);%image toolbox dependent
catch
x=sum(double(x),3)/3;%if no image toolbox do simple sum
end
end
x=double(x);%make sure the input is in double format
[output,count,m,svec]=facefind(x);%run default face detection (full scan)
imagesc(x), colormap(gray)%show image
plotbox(output)%show the detections as red squares
plotsize(x,m)%draw the minimum and maximum face size boxes in top left
function [output,count,m,svec]=facefind(x,minf,maxf,dx,dy,sens);
function [output,count,m,svec]=facefind(x,minf,maxf,dx,dy,sens);
%
%INPUT:
%x - grayscale image, double format (typical in range 0-1)
%minf - minimun face size to find [default 32]
%maxf - maximum face size to find [default inf]
%dx - number of pixel jump in x-direction [default 1]
%dy - number of pixel jump in y-direction [default 1]
%sens - sensitivity of detection on a scale from 1 to 10 [default 5]
% sens = 1 -> misses fewer faces, more false accepted faces
% sens = 10 -> misses more faces, fewer false accepted faces
%
%OUTPUT:
%output - matrix with positions and scale information for
% found faces
% output(:,1) - [x1 x2 y1 y2].'
%count - number of patches evaluated for detection
%m - true (recalculated) minf and maxf m=[minf maxf]
%svec - scales of image used [x_s;y_s] (s - scale index)
%
%INFO:
%The input parameters minf, maxf, dx, dy and sens will get their
%default value if an empty matrix is given as input. For example:
%[output,count,m,svec]=facefind(x,[],[],[],[],7);
%will change the sensitivity value to 7 but keep the default
%values for minf, maxf, dx and dy.
But all the lines of the function function[output,count,m,svec]=facefind(x,minf,maxf,dx,dy,sens); is written as comment lines. But the program runs well and also give me output. I don’t know the programmer to ask this. So I beg your help. Can anyone please help me to understand why and how this function runs?
Thanks

vienthong10 tphcm on 25 Apr 2014
This is also my concern. I hopes people help me. thanks so much!!