i am having problem using a HistogramBasedTracker as it is showing "Error using HistogramBasedTracker Expected R to be of size 1x4 when it is actually size 2x4." how to solve it?

i am new in MATLAB and making a face detector using image Image Acquisition Toolbox but a error is showing every time i ran the code....the error is like: " Error using HistogramBasedTracker

Expected R to be of size 1x4 when it is actually size 2x4.

Error in vision.HistogramBasedTracker/initializeObject (line 281)

validateattributes(roi, {'numeric'}, ...

Error in maybefinal (line 20)

initializeObject(tracker, hueChannel, noseBBox);"

but code is given below : " viddevice= imaq.VideoDevice('winvideo', 1, 'MJPG_640x400');

vidplayerobject= vision.VideoPlayer;

vidplayerobject.Name = 'facedetected Video';

faceDetector = vision.CascadeObjectDetector();

noseDetector = vision.CascadeObjectDetector('Nose');

tracker = vision.HistogramBasedTracker;

nFrames = 0;

while (nFrames<1500)

videoFrame=step(viddevice);

bbox = step(faceDetector, videoFrame);

 boxInserter  = vision.ShapeInserter('BorderColor','Custom',...
'CustomBorderColor',[255 255 0]);

videoOut = step(boxInserter, videoFrame,bbox);

faceImage = imcrop(videoFrame,bbox);

noseBBox = step(noseDetector,faceImage);

noseBBox(1:2) = noseBBox(1:2) + bbox(1:2);

initializeObject(tracker, hueChannel, noseBBox);

[hueChannel,~,~] = rgb2hsv(videoFrame);

bbox = step(tracker, hueChannel);

videoOut = step(boxInserter, videoFrame, bbox);

step(vidplayerobject,videoOut);

nFrames = nFrames + 1;

end

release(viddevice);

release(vidplayerobject);

release(faceDetector);

release(noseDetector);

release(tracker); " i am not understanding the problem........... so i will be greatfull if someone help me with my codes and the way to solve the error..

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

Answer 1

[Walter Roberson]

For debugging, after the statement

noseBBox = step(noseDetector,faceImage);

please show size(noseBBox) and size(bbox)

Question: what would the face detector and nose detector return if there were two faces in the image?

[muinbun]

thnx for your hints...... now its working

[Arif]

i did not get any clue(my bad). can you explain a little bit