diff --git a/heartRateEstimation.m b/heartRateEstimation.m
index 3fd51f9..8dde60a 100644
--- a/heartRateEstimation.m
+++ b/heartRateEstimation.m
@@ -2,16 +2,14 @@
 %%%%%%%%%%%%%%%%%
 % hr = heartRateEstimation(imgDirectory, fps, windowDuration, windowShift)
 %
-% Task:
+% Task: Finding the heartrate of person from selcted images
 %
 % Inputs:
 %	-imgDirectory
-% 	-fps
-%	-windowDuration
-%	-windowShift
+% -fps
 %
 % Output:
-%	-hr:
+%	-heartrate:
 %
 % Author: Thomas Périn
 % Date: 17/02/2023
@@ -22,11 +20,9 @@
 clc
 clear all
 
-%temp var
-%imgDirectory = 'img';
+% temp var
 fps = 15;
 windowDuration = 30;
-windowShift = 1;
 roi = [280 580 600 850];
 
 % global
@@ -34,20 +30,16 @@ redChannel = [];
 greenChannel = [];
 blueChannel = [];
 
-%list the images
-%listImg = dir([imgDirectory '/*.png']);
+%list the images with i the same directory
 listImg = dir(['*.png']);
 
+% iteration for every images available
 for l_img=1:windowDuration*fps
 	% load the current image
-	%image_original = imread([imgDirectory '/' listImg(l_img).name]);
   image_original = imread([listImg(l_img).name]);
-	%image(image_original);
-  %imshow([listImg(l_img).name])
 
 	% crop the current image around the face
 	image_face = image_original(roi(1):roi(2), roi(3):roi(4), :);
-	%image(image_face);
 
 	% spatial average for r, g, b channels
 	r_mean = mean(mean(image_face(:,:,1)));
@@ -69,15 +61,16 @@ blueChannel_avg = mean(blueChannel);
 blueChannel_std = std(blueChannel);
 
 % normalize your data
-%first define length of our data
+% first define length of our data
 L = columns(greenChannel);
 for i=1:L
   greenChannel_normalized(i) = (greenChannel(i) - greenChannel_avg)/greenChannel_std;
 end
 
+% select only greenChannel for simplicity (no ICA)
 greenChannel_fft = fft(greenChannel_normalized);
 
-% power spectrum (https://www.mathworks.com/help/matlab/ref/fft.html)
+% power spectrum using link(https://www.mathworks.com/help/matlab/ref/fft.html)
 P2 = abs(greenChannel_fft/L);
 P1 = P2(1:L/2+1);
 P1(2:end-1) = 2*P1(2:end-1);
@@ -85,21 +78,14 @@ f = 15*(0:(L/2))/L;
 plot(f,P1)
 
 % find the peak in the range ([0.75 4] Hz)
-% max -> value, index
-
-low_index = 0.75*L/15+0.5
-high_index = 2*L/15
-a = max(P1(low_index:high_index))
-heart_rate = f(a)
-
-
-% convert the index from Hz to bpm
+% define range and round to get intergers
+low_index = round(0.75*L/15);
+high_index = round(2*L/15);
+% find max value and index inn new range
+[a, ia] = max(P1(low_index:high_index));
+% adapt the index for full range
+heart_frequency = f(ia+low_index)
 
 % determine heart rate
-
-
-
-
-
-
-
+% convert the index from Hz to bpm
+heart_rate = heart_frequency*60