question of matlab arduino

i have code in matlab

if true
  % code
end
close all;
clear all;
clc;
rgbInputImage = imread('sedang (7).jpg');
rgbInputImage = imresize(rgbInputImage, 0.234);
sharpfilter = fspecial('unsharp');
rgbInputImage = imfilter(rgbInputImage, sharpfilter, 'replicate');
gaussianfilter = fspecial('gaussian', [7 7], 5);
rgbInputImage = imfilter(rgbInputImage, gaussianfilter, 'symmetric', 'conv');
labInputImage = applycform(rgbInputImage,makecform('srgb2lab'));
Lbpdfhe = uint8(labInputImage(:,:,1));
labOutputImage = cat(3,Lbpdfhe,labInputImage(:,:,2),labInputImage(:,:,3));
rgbOutputImage = applycform(labOutputImage,makecform('lab2srgb'));
figure, imshow(rgbInputImage);
figure, imshow(rgbOutputImage);
img=rgbOutputImage;
final_image = zeros(size(img,1), size(img,2));
if(size(img, 3) > 1)
for i = 1:size(img,1)
for j = 1:size(img,2)
r = img(i,j,1);
g = img(i,j,2);
b  = img(i,j,3);
if (r > 92 && g > 40 && b > 20)
v=[r,g,b];
if((max(v) - min(v)) > 15)
if(abs(r-g) > 15 && r > g && r >b)
final_image(i,j) = 1;
end
end
end
end
end
end
binaryImage=im2bw(final_image,0.6);
figure, imshow(binaryImage);
binaryImage = imfill(binaryImage, 'holes');
figure, imshow(binaryImage);
binaryImage = bwareaopen(binaryImage,1000);
figure,imshow(binaryImage);
labeledImage = bwlabel(binaryImage, 8);
blobMeasurements = regionprops(labeledImage, final_image, 'all');
numberOfPeople = size(blobMeasurements, 1)
imagesc(rgbInputImage); title('Outlines, from bwboundaries()');
hold on;
boundaries = bwboundaries(binaryImage);
for k = 1 : numberOfPeople
thisBoundary = boundaries{k};
plot(thisBoundary(:,2), thisBoundary(:,1), 'g', 'LineWidth', 2);
end
imagesc(rgbInputImage);
hold on;
title('Original with bounding boxes');
for k = 1 : numberOfPeople
thisBlobsBox = blobMeasurements(k).BoundingBox;
x1 = thisBlobsBox(1);
y1 = thisBlobsBox(2);
x2 = x1 + thisBlobsBox(3);
y2 = y1 + thisBlobsBox(4);
x = [x1 x2 x2 x1 x1];
y = [y1 y1 y2 y2 y1];
plot(x, y, 'LineWidth', 2);
end                  
hold on;
if (numberOfPeople >= 9)
 text(200,50,strcat('\color{green}kondisi: sepi'))
 disp('kondisi : sepi')
  else if (numberOfPeople <= 13)
text(200,50,strcat('\color{green}kondisi : ramai'))
disp('kondisi : ramai')
end
end
s = serial('com3','BAUD', 9600);
fopen(s);
for m=1:10
numberOfPeople=numberOfPeople;
fprintf(s,'%s',numberOfPeople,'sync');
end
fclose(s);

and code in arduino

 if true
    % code
  end
#include <LiquidCrystal.h>
LiquidCrystal lcd(8,9,4,5,6,7);
int numberOfPeople;
void setup(){
Serial.begin(9600);
lcd.begin(16,1);
}
void loop()
{
if(Serial.available())
{ 
  numberOfPeople=Serial.read();
  lcd.setCursor(0,0);
  lcd.print(numberOfPeople);
  delay(1000);
}
}

sometimes lcd display execution from matlab but sometimes lcd not display execution from matlab. why? what solution about this? or my code is wrong?