Detection problem in a video for hand detection?

I'm doing hand detection and tracking using skin color method. I'm not using Viola-Jones method as it requires training. The problem is that when i use the detection code(shown below) the hand is detected but when i use the same code in a video nothing is detected.

The code for the detection of hand is;

%Read the image, and capture the dimensions
tic;
img_orig = imread('65.png');
height = size(img_orig,1);
width = size(img_orig,2);

%Initialize the output images
out = img_orig;
bin = zeros(height,width);

%Convert the image from RGB to YCbCr
img_ycbcr = rgb2ycbcr(img_orig);
Cb = img_ycbcr(:,:,2);
Cr = img_ycbcr(:,:,3);

%Detect Skin
[r,c,v] = find(Cb>=67 & Cb<=137 & Cr>=133 & Cr<=173);
numind = size(r,1);
numcol = size(r,2);

%Mark Skin Pixels
for i=1:numind
    out(r(i),c(i),:) = [0 0 255];
    bin(r(i),c(i)) = 1;
end

% Detect radius
[x1,y1] = find(out(:,:,3) == 255, 1,'first');
[x2,y2] = find(out(:,:,3) == 255, 1, 'last');

% Detect Hand Center
hits = 0;
hitsArr = zeros(1,height);
for i = 1:height
    hits = numel(find(bin(i,:) == 1));
    hitsArr(i) = hits;
end
maxHitr = max(hitsArr);
y =  find(hitsArr == maxHitr,1,'first');

hitsArr = zeros(1,width);
for i = 1:width
    hits = numel(find(bin(:,i) == 1));
    hitsArr(i) = hits;
end
maxHitc = max(hitsArr);
x = find(hitsArr == maxHitc,1,'first');

label = 'Hand';
position = [x y abs(y2-y1)/2; x y 1];
img_out = insertObjectAnnotation(img_orig,'Circle',position,label);
imshow(img_orig);
figure; imshow(img_out);title('Detected hand');
imwrite(img_out,'hand_detect.jpg');
% viscircles([x y],abs(y2-y1)/2,'EdgeColor','r');
% viscircles([x y],1,'EdgeColor','r');
% figure; imshow(out);
figure; imshow(bin);
toc;

and image for the detected hand is

Now when i use the code for detection in a video nothing is detected.

the code is this;

filename = 'hand_2.wmv';
video = vision.VideoFileReader(filename);
player = vision.DeployableVideoPlayer('Location', [10,100],'FrameRate',30);

while ~isDone(video)
    img_orig = step(video);

      % Capture the dimensions
      height = size(img_orig,1);
      width = size(img_orig,2);

      %Initialize the output images
      out = img_orig;
      bin = zeros(height,width);

      %Convert the image from RGB to YCbCr
      img_uint8 = uint8(img_orig);
      img_ycbcr = rgb2ycbcr(img_uint8);
      Cb = img_ycbcr(:,:,2);
      Cr = img_ycbcr(:,:,3);

      %Detect Skin
      [r,c,v] = find(Cb>=67 & Cb<=137 & Cr>=133 & Cr<=173);
      numind = size(r,1);

      %Mark Skin Pixels
      for i=1:numind
          out(r(i),c(i),:) = [0 0 255];
          bin(r(i),c(i)) = 1;
      end

      % Detect radius
      [x1,y1] = find(out(:,:,3) == 255, 1,'first');
      [x2,y2] = find(out(:,:,3) == 255, 1, 'last');
      if isempty(y1) && isempty(y2)
          y1 = 2; y2 = 0;
      end

      % Detect Hand Center
      hits = 0;
      hitsArr = zeros(1,height);
      for i = 1:height
          hits = numel(find(bin(i,:) == 1));
          hitsArr(i) = hits;
      end
      maxHitr = max(hitsArr);
      y =  find(hitsArr == maxHitr,1,'first');

      hitsArr = zeros(1,width);
      for i = 1:width
          hits = numel(find(bin(:,i) == 1));
          hitsArr(i) = hits;
      end
      maxHitc = max(hitsArr);
      x = find(hitsArr == maxHitc,1,'first');

      label = 'Hand';
      position = [x y abs(y2-y1)/2; x y 1];
      img_out = insertObjectAnnotation(img_orig,'Circle',position,label);
      step(player, img_out);

end

release(video);
release(player);

What could be the problem?

[Sadiq]

hi dear i am working on the same project, my task is also to recognize hand from video frames, it will be very nice of you if you help me,, my email id is [e-mail],

[Awais Bilal]

Hello Mr.Sadiq: I need some help. Please email me at [e-mail]

[Yash Gajjar]

I'm working on a similar project, but I need to use webcam and not video. I have tried changing out the image code to webcam compatible code but with no success. It would be great if you could help me with this issue...thx! [e-mail]

Answer 1

[Image Analyst]

You might need to adjust your Cb and Cr thresholds. Otherwise use the debugger to figure out where it's coming out zeros when it should be giving something non-zero.