the code is giving different finger count.

I am working on a hand gesture recognition system. The code attached below gives variable finger count. Can someone please help me fix the issue or help me with a working code of hand gesture recognition for v2017b? Some functions are used from Virtual synchronous Machine.

%%clear stored variables, command windows, close any open windows
     clear; 
     clc;
     close all; 

    %%sets videoinput to the webcam, and the webcam device 1
       vid=videoinput('winvideo', 1, 'YUY2_640x480');                           
       set(vid,'ReturnedColorspace','grayscale')

    %%pause 2 seconds before snapshot of background image
       pause(2);                                                                

    IM1=getsnapshot(vid);                                                     %get snapshot from the webcam video and store to IM1 variable
    figure(1);subplot(3,2,1);imshow(IM1);title('Background');                 %open up a figure and show the image stored in IM1 variable
    pause(2);

    IM2=getsnapshot(vid);                                                     %get snapshot of test image and store to 
    variable IM2
    figure(1);subplot(3,2,2);imshow(IM2);title('Gesture');                    %open up a figure and show the image stored in IM2 variable

IM3 = IM1 - IM2;                                                          %subtract Backround from Image
figure(1);subplot(3,2,3);imshow(IM3);title('Subtracted');                 %show the subtracted image
lvl = graythresh(IM3);                                                      %find the threshold value using Otsu's method for black and white

IM3 = im2bw(IM3, lvl);                                                      %Converts image to BW, pixels with value higher than threshold value is changed to 1, lower changed to 0
figure(1);subplot(3,2,4);imshow(IM3);title('Black&White'); 
imwrite(IM3,'gray.jpeg');

    %%data driven threshold based on the max/min of the image histogram 
        hi_grey=vsg('HighestGrey',IM3); 
        disp('highestgrey done'); 
        lo_grey=vsg('LowestGrey',IM3); 
        disp('lowestgrey done'); 
        thresh=uint8(3*(hi_grey+lo_grey)/4);

    %%display the resulting image 
        IM4=vsg('LowPass',IM3); 
        disp('lowpass done');

   %%apply the threshold to the image and display the resultant binary image 
        IM5=vsg('Threshold',IM4,thresh);
        disp('threshold done'); 
        IM5=uint8(IM5); 
        figure(1);subplot(3,2,5);imshow(IM5);

    %%invert Image
        [IM6]=vsg('Inverse',IM5);
        figure(1);subplot(3,2,6);imshow(IM6);
        title ('Inverted Binary Image');

    %%mask boundary pixels to avoid any edge effects 
        IM7=vsg('MaskImg',IM6,20); 
        figure(2);subplot(3,2,1);imshow(IM7);
        image(uint8(IM7));

    %%Get width
        [num1]=vsg('GetWidth',IM3); 
        [num2]=num1*.5;

    %%Thin
        [IM8]=vsg('ThinImg',IM7,70); 

    %%Join lines
        [IM9]=vsg('LINFilter',IM8);
        figure(2);subplot(3,2,2);imshow(IM9);
        image(uint8(IM9));

    %%Apply centroid and find position
        [IM10]=vsg('Centroid',IM9);
        [p1]=vsg('FWP',IM10);

    %%Fill Circle
        [IM11]=vsg('FillCircle',IM9,p1,num2,[0,0,0]);

    %%Fill box
        [IM12]=vsg('FillBox',IM11,[0,1200],[1400,1400],[0,0,0]);
        figure(2);subplot(3,2,3);imshow(IM11);
        image(uint8(IM12));

    %%Count the number of blobs and display finger count
        [num3]= vsg('CountBlobs',IM12);
        figure(2);subplot(3,2,4);imshow(IM12);
        image(uint8(IM2));
        text(50,50,strcat('\color{red}Finger count:',num2str(num3)))