Hi, Im trying to find the orientation that is roll and pitch angle of my platform by analysing the overall geometery of the dots. To do so i have firstly detected the dots by using standard deviation and k-means clustering and dividing the image into 5x5 boxes then a plane fitting curve method is used to determine the overall geometery of the dots which further gives orientation of the plate. The obtained angles are incorrect what might have possibly gone wrong please help and suggest any possible solution. I'm actually trying to implement a blass on a plate system and i want to detect the orientation of the plate using webcam. Also im using MATLAB 2021a therefore im not sure how to calibrate my camera for such a pattern. The MATLAB code is given below;
clear all;
clc;
close all;
% Create a webcam object
cap = webcam('Adesso CyberTrack H3');
% Adjust camera settings if supported
try
% Set the exposure time (shutter speed) in seconds
exposureTime = 0.01; % Adjust as needed
cap.ExposureMode = 'manual';
cap.Exposure = exposureTime;
catch ME
disp('Warning: Unable to set exposure time for the camera.');
disp(ME.message);
end
% Create the background subtractor object for ball detection
back_sub = vision.ForegroundDetector('NumTrainingFrames', 100, 'NumGaussians', 3, 'MinimumBackgroundRatio', 0.7);
% Create structuring element for morphological operation
se = strel('rectangle', [20, 20]);
% Initialize calibration values
calibration_pitch = 0;
calibration_roll = 0;
% Calibrate the system to set initial pitch and roll to zero
frame = snapshot(cap);
I_gray = rgb2gray(frame);
I_contrast = imadjust(I_gray);
bw = imbinarize(I_contrast, 'adaptive');
bw_filled = imfill(bw, 'holes');
bw_cleaned = bwareaopen(bw_filled, 50);
stats = regionprops('table', bw_cleaned, 'Centroid', 'BoundingBox');
centroids = stats.Centroid;
if size(centroids, 1) >= 3
X = centroids(:, 1);
Y = centroids(:, 2);
Z = linspace(0, 1, size(centroids, 1))';
A = [X, Y, ones(size(X))];
coeffs = A \ Z;
normal = [-coeffs(1), -coeffs(2), 1];
normal = normal / norm(normal);
calibration_pitch = asin(normal(1));
calibration_roll = asin(normal(2));
disp(['Calibration Pitch: ', num2str(calibration_pitch), ' degrees']);
disp(['Calibration Roll: ', num2str(calibration_roll), ' degrees']);
else
disp('Not enough dots detected for calibration.');
end
while true
% Read frame from webcam
frame = snapshot(cap);
% Part 1: Dot Detection and Tilt Angle Calculation
I_gray = rgb2gray(frame);
I_contrast = imadjust(I_gray);
bw = imbinarize(I_contrast, 'adaptive');
bw_filled = imfill(bw, 'holes');
bw_cleaned = bwareaopen(bw_filled, 50);
stats = regionprops('table', bw_cleaned, 'Centroid', 'BoundingBox');
centroids = stats.Centroid;
boundingBoxes = stats.BoundingBox;
if size(centroids, 1) >= 3
X = centroids(:, 1);
Y = centroids(:, 2);
Z = linspace(0, 1, size(centroids, 1))';
A = [X, Y, ones(size(X))];
coeffs = A \ Z;
normal = [-coeffs(1), -coeffs(2), 1];
normal = normal / norm(normal);
pitch = asin(normal(1)) - calibration_pitch;
roll = asin(normal(2)) - calibration_roll;
yaw = 0;
disp(['Pitch (Tilt around Y-axis): ', num2str(pitch), ' degrees']);
disp(['Roll (Tilt around X-axis): ', num2str(roll), ' degrees']);
disp(['Yaw (Rotation around Z-axis): ', num2str(yaw), ' degrees']);
else
pitch = 0;
roll = 0;
yaw = 0;
disp('Not enough dots detected to fit a plane.');
end
for i = 1:size(boundingBoxes, 1)
frame = insertShape(frame, 'Rectangle', boundingBoxes(i, :), 'Color', 'g', 'LineWidth', 2);
end
fg_mask = step(back_sub, frame);
fg_mask = imclose(fg_mask, se);
fg_mask = medfilt2(fg_mask, [5, 5]);
fg_mask = uint8(fg_mask) * 255;
[contours, ~] = bwlabel(fg_mask);
stats = regionprops(contours, 'Area', 'BoundingBox', 'Centroid');
if ~isempty(stats)
[~, max_index] = max([stats.Area]);
centroid = stats(max_index).Centroid;
boundingBox = stats(max_index).BoundingBox;
frame = insertShape(frame, 'Rectangle', boundingBox, 'Color', [0, 255, 0], 'LineWidth', 3);
text = ['x: ', num2str(centroid(1)), ', y: ', num2str(centroid(2))];
frame = insertText(frame, [centroid(1) - 10, centroid(2) - 10], text, 'FontSize', 50, 'TextColor', [0, 255, 0]);
coordinates = [];
coordinates = [coordinates; centroid];
disp(coordinates);
end
frame = insertText(frame, [10, 10], ['Pitch: ', num2str(pitch), '°'], 'FontSize', 18, 'BoxColor', 'red', 'TextColor', 'white');
frame = insertText(frame, [10, 40], ['Roll: ', num2str(roll), '°'], 'FontSize', 18, 'BoxColor', 'red', 'TextColor', 'white');
frame = insertText(frame, [10, 70], ['Yaw: ', num2str(yaw), '°'], 'FontSize', 18, 'BoxColor', 'red', 'TextColor', 'white');
imshow(frame);
pause(0.0001);
end
clear cap;
