Why is my Stereo Vision Live Stream Displaying a Black Box?

[PainterGuy]

I'm trying to perform depth estimation on stereo vision using live feed. I'm using two webcams. The code below doesn't give any error but I only get a block box without any sign of live video! Could you please give it a look?

leftCam = imaq.VideoDevice('winvideo', 1,    'MJPG_320x240');
rightCam = imaq.VideoDevice('winvideo', 3, 'MJPG_320x240');
leftCam.ReturnedDataType = 'uint8';
leftCam.DeviceProperties.WhiteBalanceMode = 'manual';
rightCam.ReturnedDataType = 'uint8';
rightCam.DeviceProperties.WhiteBalanceMode = 'manual';

if ~exist('stereoParams','var')
load stereocalibration
end

% Run 3D image reconstruction on live video
ax = axes;
maxDepth = 5 ;

while true

imageLeft = step(rightCam);
imageRight = step(leftCam);

% Rectify
[J1, J2] = rectifyStereoImages(imageLeft, imageRight, stereoParams, 'OutputView','Full');

J1 = rgb2gray(J1);
J2 = rgb2gray(J2);

%Compute Disparity Map
disp = disparity(J1, J2)%, 'DisparityRange', [0, 112]);

% Reconstruct 3D scene from Disparity Map
pointCloud = reconstructScene(disp, stereoParams)./1000;
% Remove all points greater then maxDepth m away from the camera
z = pointCloud(:,:,3);
z(z < 0) = NaN;
z(z > maxDepth) = NaN;
pointCloud(:,:,3) = z;
% Continue running until figure window is closed
if ~ishandle(ax)
    break;
else

pcshow(pointCloud, J1,    'VerticalAxis',    'Y','VerticalAxisDir',    'Down',    'Parent', ax);

xlabel('X (m)');
ylabel('Y (m)');
zlabel('Z (m)');
xlim(ax, [-.8,    .8]); %-0.8 to 8
ylim(ax, [-.8, .8]);    %-0.8 to 8
zlim(ax, [0, maxDepth]);
daspect(ax,'manual');
pbaspect(ax,'manual');
drawnow;
end
 endrelease(leftCam)
release(rightCam)

 

[Adrmay]

It looks like there is an issue with your code. Specifically, the line <code>imageLeft = step(rightCam)</code> and <code>imageRight = step(leftCam)</code> need to be switched so that imageLeft is coming from the leftCam and imageRight is coming from the rightCam.