How to detect the movement of the two tapping fingers in a video?

Please, I'm trying to detect the fingers' movement in a video. Firstly, I'd like to apply a skin color detection to separate the hand from the background and then I'll find the hand counter followed by calculating the convex points to detect the fingers. What I want now from this video is a new video showing only the movement of the two tapping fingers (or their contour), as shown in this figure.

Please, I'm trying to detect the fingers' movement in a video. Firstly, I'd like to apply a skin color detection to separate the hand from the background and then I'll find the hand counter followed by calculating the convex points to detect the fingers. What I want now from this video is a new video showing only the movement of the two tapping fingers (or their contour), as shown in this figure.

enter image description here

I used this code to detect the skin color:

function OutImg=Skin_Detect(I)
% clear
% I=imread('D:\New Project\Movie Frames from RLC_L_FTM_IP60\Frame     
0002.png');
I=double(I);
[hue,s,v]=rgb2hsv(I);
cb =  0.148* I(:,:,1) - 0.291* I(:,:,2) + 0.439 * I(:,:,3) + 128;
cr =  0.439 * I(:,:,1) - 0.368 * I(:,:,2) -0.071 * I(:,:,3) + 128;
[w h]=size(I(:,:,1));
for i=1:w
   for j=1:h            
       if  138<=cr(i,j) && cr(i,j)<=169 && 136<=cb(i,j) && cb(i,j)<=200 && 
          0.01<=hue(i,j) && hue(i,j)<=0.2     
         segment(i,j)=1;            
     else       
          segment(i,j)=0;    
     end    
  end
end

 % imshow(segment);
 OutImg(:,:,1)=I(:,:,1).*segment;   
 OutImg(:,:,2)=I(:,:,2).*segment; 
 OutImg(:,:,3)=I(:,:,3).*segment; 
 % figure,imshow(uint8(im));
The same code is working perfectly when I apply it to an image, but I detect nothing when I apply it to a video, as follows:

 videoFReader = vision.VideoFileReader('RLC_L_FT_IP60.m4v');
 % Create a video player object for displaying video frames.
 videoPlayer = vision.DeployableVideoPlayer;

 % Display the original video
 while ~isDone(videoFReader)
       videoFrame = step(videoFReader);
       % Track using the Hue channel data
        Out=Skin_Detect(videoFrame);
        step(videoPlayer,Out);
 end
Please, any suggestion and idea to solve this problem?

I'll be so grateful if anyone can help with this even with different codes. Thank you in advance.