im trying to run matlab video processing code and getting this error "Index in position 1 exceeds array bounds (must not exceed 1).

clear all

clc

% Create a VideoCapture object

cap = webcam;

% Create the background subtractor object

% Use the last 700 video frames to build the background

back_sub = vision.ForegroundDetector('NumTrainingFrames', 700, 'InitialVariance', 25);

% Create a structuring element for morphological operations

% You can tweak the dimensions of the element

% e.g. instead of [20, 20], you can try [30, 30].

se = strel('rectangle', [20, 20]);

while(true)

% Capture frame-by-frame

frame = snapshot(cap);

% Use every frame to calculate the foreground mask and update

% the background

fg_mask = step(back_sub, frame);

% Close dark gaps in foreground object using closing

fg_mask = imclose(fg_mask, se);

% Remove salt and pepper noise with a median filter

fg_mask = medfilt2(fg_mask, [5, 5]);

% % Threshold the image to make it either black or white

fg_mask = uint32(fg_mask);

fg_mask = (imbinarize(fg_mask));

% % Find the index of the largest contour and draw bounding box

fg_mask_bb = fg_mask;

stats = regionprops(fg_mask_bb, 'Area', 'BoundingBox', 'Centroid');

areas = [stats.Area];

% If there are no contours

if isempty(areas)

% Display the resulting frame

imshow(frame);

% % If any key is pressed on the keyboard,

% % exit this loop

% key = getkeywait(1);

% if ~isempty(key)

% break;

% end

% Go to the top of the while loop

continue;

else

% Find the largest moving object in the image

[~, max_index] = max(areas);

end

clear cap;

% Draw the bounding box

x = round(stats(max_index).BoundingBox(1));

y = round(stats(max_index).BoundingBox(2));

w = round(stats(max_index).BoundingBox(3));

h = round(stats(max_index).BoundingBox(4));

rectangle('Position', [x, y, w, h], 'EdgeColor', [0, 0, 1], 'LineWidth', 3);

% Draw circle in the center of the bounding box

x2 = x + round(w/2);

y2 = y + round(h/2);

viscircles([x2, y2], 4, 'EdgeColor', [0, 1, 0], 'LineWidth', 2);

% Print the centroid coordinates (we'll use the center of the

% bounding box) on the image

text = sprintf('x: %d, y: %d', x2, y2);

textLocation = [x2 - 10, y2 - 10];

textH = text('Position', textLocation, 'String', text, 'FontSize', 12, 'Color', [0, 1, 0]);

% Display the resulting frame

imshow(frame);

% If any key is pressed on the keyboard,

% exit this loop

key = getkeywait(1);

if ~isempty(key)

break;

end

end

% Close down the video stream

clear cap;

this code is working pretty well however, this is error im getting.

Index in position 1 exceeds array bounds (must not exceed 1).

Error in imagepro (line 74)

textH = text('Position', textLocation, 'String', text, 'FontSize', 12, 'Color', [0, 1, 0]);

Answer 1

[recent works]

The error you are encountering, "Index in position 1 exceeds array bounds (must not exceed 1)," suggests that there is an issue with the index you are trying to access. In your code, the error occurs at line 74 when you are trying to create a text object.

Based on your code, it appears that you are trying to display text on an image. The error message suggests that the textLocation variable might be exceeding the array bounds. This usually happens when textLocation is a 2-element vector representing the x and y coordinates, and one of these values is not within the valid bounds.

To resolve this issue, you should check the values of x2 and y2 that you are using to set the textLocation. Make sure that these values are within the valid bounds of your image. You can use size(frame) to get the dimensions of your image and then ensure that x2 and y2 are within these bounds.

% ...

while(true)

% Capture frame-by-frame

frame = snapshot(cap);

% Use every frame to calculate the foreground mask and update

% the background

fg_mask = step(back_sub, frame);

% Close dark gaps in foreground object using closing

fg_mask = imclose(fg_mask, se);

% Remove salt and pepper noise with a median filter

fg_mask = medfilt2(fg_mask, [5, 5]);

% Threshold the image to make it either black or white

fg_mask = uint32(fg_mask);

fg_mask = (imbinarize(fg_mask));

% Find the index of the largest contour and draw bounding box

fg_mask_bb = fg_mask;

stats = regionprops(fg_mask_bb, 'Area', 'BoundingBox', 'Centroid');

areas = [stats.Area];

% If there are no contours

if isempty(areas)

% Display the resulting frame

imshow(frame);

% Go to the top of the while loop

continue;

else

% Find the largest moving object in the image

[~, max_index] = max(areas);

end

% Draw the bounding box

x = round(stats(max_index).BoundingBox(1));

y = round(stats(max_index).BoundingBox(2));

w = round(stats(max_index).BoundingBox(3));

h = round(stats(max_index).BoundingBox(4));

% Check if x and y are within image bounds

x2 = x + round(w/2);

y2 = y + round(h/2);

[imageHeight, imageWidth, ~] = size(frame);

if x2 < 1

x2 = 1;

elseif x2 > imageWidth

x2 = imageWidth;

end

if y2 < 1

y2 = 1;

elseif y2 > imageHeight

y2 = imageHeight;

end

% Draw circle in the center of the bounding box

viscircles([x2, y2], 4, 'EdgeColor', [0, 1, 0], 'LineWidth', 2);

% Print the centroid coordinates (we'll use the center of the

% bounding box) on the image

text = sprintf('x: %d, y: %d', x2, y2);

textLocation = [x2 - 10, y2 - 10];

textH = text('Position', textLocation, 'String', text, 'FontSize', 12, 'Color', [0, 1, 0]);

% Display the resulting frame

imshow(frame);

% If any key is pressed on the keyboard,

% exit this loop

key = getkeywait(1);

if ~isempty(key)

break;

end

end

% ...

Answer 2

[Walter Roberson]

text = sprintf('x: %d, y: %d', x2, y2);

After that line text is now a variable rather than a function.