%% Parameters groupList = ["/images/MOT_3D_Camera/in_situ_absorption", "/images/ODT_1_Axis_Camera/in_situ_absorption", ... "/images/ODT_2_Axis_Camera/in_situ_absorption", "/images/Horizontal_Axis_Camera/in_situ_absorption", ... "/images/Vertical_Axis_Camera/in_situ_absorption"]; folderPath = "C:/Users/Karthik/Documents/GitRepositories/Calculations/Data-Analyzer/15042025/"; run = '0035'; folderPath = strcat(folderPath, run); cam = 5; angle = 0; center = [1300, 2108]; span = [200, 200]; fraction = [0.1, 0.1]; pixel_size = 5.86e-6; removeFringes = false; % scan_parameter = 'rot_mag_fin_pol_angle'; % scan_parameter = 'rot_mag_field'; scan_parameter = 'rot_mag_field_up'; % scan_parameter_text = 'Angle = '; scan_parameter_text = 'BField = '; font = 'Bahnschrift'; skipPreprocessing = true; skipMasking = true; skipIntensityThresholding = true; skipBinarization = true; %% Compute OD image, rotate and extract ROI for analysis % Get a list of all files in the folder with the desired file name pattern. filePattern = fullfile(folderPath, '*.h5'); files = dir(filePattern); refimages = zeros(span(1) + 1, span(2) + 1, length(files)); absimages = zeros(span(1) + 1, span(2) + 1, length(files)); for k = 1 : length(files) baseFileName = files(k).name; fullFileName = fullfile(files(k).folder, baseFileName); fprintf(1, 'Now reading %s\n', fullFileName); atm_img = im2double(imrotate(h5read(fullFileName, append(groupList(cam), "/atoms")), angle)); bkg_img = im2double(imrotate(h5read(fullFileName, append(groupList(cam), "/background")), angle)); dark_img = im2double(imrotate(h5read(fullFileName, append(groupList(cam), "/dark")), angle)); refimages(:,:,k) = subtractBackgroundOffset(cropODImage(bkg_img, center, span), fraction)'; absimages(:,:,k) = subtractBackgroundOffset(cropODImage(calculateODImage(atm_img, bkg_img, dark_img), center, span), fraction)'; end % Fringe removal if removeFringes optrefimages = removefringesInImage(absimages, refimages); absimages_fringe_removed = absimages(:, :, :) - optrefimages(:, :, :); nimgs = size(absimages_fringe_removed,3); od_imgs = cell(1, nimgs); for i = 1:nimgs od_imgs{i} = absimages_fringe_removed(:, :, i); end else nimgs = size(absimages(:, :, :),3); od_imgs = cell(1, nimgs); for i = 1:nimgs od_imgs{i} = absimages(:, :, i); end end %% Get rotation angles scan_parameter_values = zeros(1, length(files)); % Get information about the '/globals' group for k = 1 : length(files) baseFileName = files(k).name; fullFileName = fullfile(files(k).folder, baseFileName); info = h5info(fullFileName, '/globals'); for i = 1:length(info.Attributes) if strcmp(info.Attributes(i).Name, scan_parameter) if strcmp(scan_parameter, 'rot_mag_fin_pol_angle') scan_parameter_values(k) = 180 - info.Attributes(i).Value; else scan_parameter_values(k) = info.Attributes(i).Value; end end end end %% Run Fourier analysis over images fft_imgs = cell(1, nimgs); spectral_weight = zeros(1, nimgs); % Create VideoWriter object for movie videoFile = VideoWriter('Single_Shot_FFT.mp4', 'MPEG-4'); videoFile.Quality = 100; % Set quality to maximum (0–100) videoFile.FrameRate = 2; % Set the frame rate (frames per second) open(videoFile); % Open the video file to write % Display the cropped image for k = 1 : length(od_imgs) IMG = od_imgs{k}; [IMGFFT, IMGPR] = computeFourierTransform(IMG, skipPreprocessing, skipMasking, skipIntensityThresholding, skipBinarization); figure(1); clf set(gcf,'Position',[500 100 1000 800]) t = tiledlayout(2, 2, 'TileSpacing', 'compact', 'Padding', 'compact'); % 1x4 grid % Calculate the x and y limits for the cropped image y_min = center(1) - span(2) / 2; y_max = center(1) + span(2) / 2; x_min = center(2) - span(1) / 2; x_max = center(2) + span(1) / 2; % Generate x and y arrays representing the original coordinates for each pixel x_range = linspace(x_min, x_max, span(1)); y_range = linspace(y_min, y_max, span(2)); % Display the cropped OD image ax1 = nexttile; imagesc(x_range, y_range, IMG) % Define normalized positions (relative to axis limits) x_offset = 0.025; % 5% offset from the edges y_offset = 0.025; % 5% offset from the edges % Top-right corner (normalized axis coordinates) hText = text(1 - x_offset, 1 - y_offset, [scan_parameter_text, num2str(scan_parameter_values(k), '%.1f')], ... 'Color', 'white', 'FontWeight', 'bold', 'Interpreter', 'tex', 'FontSize', 20, 'Units', 'normalized', 'HorizontalAlignment', 'right', 'VerticalAlignment', 'top'); axis equal tight; hcb = colorbar; colormap(ax1, 'jet'); set(gca, 'FontSize', 14); % For tick labels only hL = ylabel(hcb, 'Optical Density'); set(hL,'Rotation',-90); set(gca,'YDir','normal') set(gca, 'YTick', linspace(y_min, y_max, 5)); % Define y ticks set(gca, 'YTickLabel', flip(linspace(y_min, y_max, 5))); % Flip only the labels hXLabel = xlabel('x (pixels)', 'Interpreter', 'tex'); hYLabel = ylabel('y (pixels)', 'Interpreter', 'tex'); hTitle = title('OD Image', 'Interpreter', 'tex'); set([hXLabel, hYLabel, hL, hText], 'FontName', font) set([hXLabel, hYLabel, hL], 'FontSize', 14) set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title % Plot the processed image ax2 = nexttile; imagesc(x_range, y_range, IMGPR) axis equal tight; hcb = colorbar; colormap(ax2, 'parula'); set(gca, 'FontSize', 14); % For tick labels only set(gca,'YDir','normal') set(gca, 'YTick', linspace(y_min, y_max, 5)); % Define y ticks set(gca, 'YTickLabel', flip(linspace(y_min, y_max, 5))); % Flip only the labels hXLabel = xlabel('x (pixels)', 'Interpreter', 'tex'); hYLabel = ylabel('y (pixels)', 'Interpreter', 'tex'); hTitle = title('Processed Image', 'Interpreter', 'tex'); set([hXLabel, hYLabel], 'FontName', font) set([hXLabel, hYLabel], 'FontSize', 14) set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title % Plot the power spectrum ax3 = nexttile; [rows, cols] = size(IMGFFT); zoom_size = 50; % Zoomed-in region around center mid_x = floor(cols/2); mid_y = floor(rows/2); fft_imgs{k} = IMGFFT(mid_y-zoom_size:mid_y+zoom_size, mid_x-zoom_size:mid_x+zoom_size); imagesc(log(1 + abs(fft_imgs{k}).^2)); % Define normalized positions (relative to axis limits) x_offset = 0.025; % 5% offset from the edges y_offset = 0.025; % 5% offset from the edges axis equal tight; hcb = colorbar; colormap(ax3, 'jet'); set(gca, 'FontSize', 14); % For tick labels only set(gca,'YDir','normal') hXLabel = xlabel('k_x', 'Interpreter', 'tex'); hYLabel = ylabel('k_y', 'Interpreter', 'tex'); hTitle = title('Power Spectrum - S(k_x,k_y)', 'Interpreter', 'tex'); set([hXLabel, hYLabel, hText], 'FontName', font) set([hXLabel, hYLabel], 'FontSize', 14) set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title % Plot the angular distribution nexttile [theta_vals, S_theta] = computeNormalizedAngularSpectralDistribution(fft_imgs{k}, 10, 20, 180, 75, 2); spectral_weight(k) = trapz(theta_vals, S_theta); plot(theta_vals/pi, S_theta,'Linewidth',2); set(gca, 'FontSize', 14); % For tick labels only hXLabel = xlabel('\theta/\pi [rad]', 'Interpreter', 'tex'); hYLabel = ylabel('Normalized magnitude (a.u.)', 'Interpreter', 'tex'); hTitle = title('Angular Spectral Distribution - S(\theta)', 'Interpreter', 'tex'); set([hXLabel, hYLabel, hText], 'FontName', font) set([hXLabel, hYLabel], 'FontSize', 14) set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title grid on drawnow pause(0.5) % Capture the current frame and write it to the video frame = getframe(gcf); % Capture the current figure as a frame writeVideo(videoFile, frame); % Write the frame to the video end % Close the video file close(videoFile); %% Track spectral weight across the transition % Assuming scan_parameter_values and spectral_weight are column vectors (or row vectors of same length) [unique_scan_parameter_values, ~, idx] = unique(scan_parameter_values); % Preallocate arrays mean_sf = zeros(size(unique_scan_parameter_values)); stderr_sf = zeros(size(unique_scan_parameter_values)); % Loop through each unique theta and compute mean and standard error for i = 1:length(unique_scan_parameter_values) group_vals = spectral_weight(idx == i); mean_sf(i) = mean(group_vals); stderr_sf(i) = std(group_vals) / sqrt(length(group_vals)); % standard error = std / sqrt(N) end figure(2); set(gcf,'Position',[100 100 950 750]) errorbar(unique_scan_parameter_values, mean_sf, stderr_sf, 'o--', ... 'LineWidth', 1.5, 'MarkerSize', 6, 'CapSize', 5); set(gca, 'FontSize', 14); % For tick labels only % hXLabel = xlabel('\alpha (degrees)', 'Interpreter', 'tex'); hXLabel = xlabel('B_z (G)', 'Interpreter', 'tex'); hYLabel = ylabel('Spectral Weight', 'Interpreter', 'tex'); hTitle = title('Change across transition', 'Interpreter', 'tex'); set([hXLabel, hYLabel], 'FontName', font) set([hXLabel, hYLabel], 'FontSize', 14) set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title grid on %% k-means Clustering % Reshape to column vector X = mean_sf(:); % Determine the number of clusters to try (you can experiment with different values here) optimalClusters = 3; % Based on prior knowledge or experimentation % Set the random seed for reproducibility rng(42); % Specify initialization method ('plus' is the default) startMethod = 'plus'; % Options: 'uniform', 'plus', 'sample' % Apply K-means clustering with controlled initialization [idx, C] = kmeans(X, optimalClusters, 'Start', startMethod); % Plot the results figure(3); set(gcf,'Position',[100 100 950 750]) hold on; % Plot error bars with mean_sf and stderr_sf errorbar(unique_scan_parameter_values, mean_sf, stderr_sf, 'o--', ... 'LineWidth', 1.5, 'MarkerSize', 6, 'CapSize', 5); % Scatter plot for data points (showing clusters) scatter(unique_scan_parameter_values, X, 50, idx, 'filled'); % Get the current y-axis limits current_ylim = ylim; % Generate colors for each cluster colors = lines(optimalClusters); % Create distinct colors for each cluster % Loop through each cluster and fill the regions for i = 1:optimalClusters % Find indices of data points that belong to the current cluster clusterIdx = find(idx == i); % Find the range of x-values for this cluster x_min = unique_scan_parameter_values(clusterIdx(1)); % Starting x-value for the cluster x_max = unique_scan_parameter_values(clusterIdx(end)); % Ending x-value for the cluster % Fill the region corresponding to the cluster fill([x_min, x_max, x_max, x_min], ... [current_ylim(1), current_ylim(1), current_ylim(2), current_ylim(2)], ... colors(i, :), 'EdgeColor', 'none', 'FaceAlpha', 0.3); % Add transparency end hXLabel = xlabel('\alpha (degrees)', 'Interpreter', 'tex'); hYLabel = ylabel('Spectral Weight', 'Interpreter', 'tex'); hTitle = title('Regimes identified by k-means clustering', 'Interpreter', 'tex'); set([hXLabel, hYLabel], 'FontName', font) set([hXLabel, hYLabel], 'FontSize', 14) set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title grid on; hold off; %% Helper Functions function [IMGFFT, IMGPR] = computeFourierTransform(I, skipPreprocessing, skipMasking, skipIntensityThresholding, skipBinarization) % computeFourierSpectrum - Computes the 2D Fourier power spectrum % of binarized and enhanced lattice image features, with optional central mask. % % Inputs: % I - Grayscale or RGB image matrix % % Output: % F_mag - 2D Fourier power spectrum (shifted) if ~skipPreprocessing % Preprocessing: Denoise filtered = imgaussfilt(I, 10); IMGPR = I - filtered; % adjust sigma as needed else IMGPR = I; end if ~skipMasking [rows, cols] = size(IMGPR); [X, Y] = meshgrid(1:cols, 1:rows); % Elliptical mask parameters cx = cols / 2; cy = rows / 2; % Shifted coordinates x = X - cx; y = Y - cy; % Ellipse semi-axes rx = 0.4 * cols; ry = 0.2 * rows; % Rotation angle in degrees -> radians theta_deg = 30; % Adjust as needed theta = deg2rad(theta_deg); % Rotated ellipse equation cos_t = cos(theta); sin_t = sin(theta); x_rot = (x * cos_t + y * sin_t); y_rot = (-x * sin_t + y * cos_t); ellipseMask = (x_rot.^2) / rx^2 + (y_rot.^2) / ry^2 <= 1; % Apply cutout mask IMGPR = IMGPR .* ellipseMask; end if ~skipIntensityThresholding % Apply global intensity threshold mask intensity_thresh = 0.20; intensity_mask = IMGPR > intensity_thresh; IMGPR = IMGPR .* intensity_mask; end if ~skipBinarization % Adaptive binarization and cleanup IMGPR = imbinarize(IMGPR, 'adaptive', 'Sensitivity', 0.0); IMGPR = imdilate(IMGPR, strel('disk', 2)); IMGPR = imerode(IMGPR, strel('disk', 1)); IMGPR = imfill(IMGPR, 'holes'); F = fft2(double(IMGPR)); % Compute 2D Fourier Transform IMGFFT = abs(fftshift(F))'; % Shift zero frequency to center else F = fft2(double(IMGPR)); % Compute 2D Fourier Transform IMGFFT = abs(fftshift(F))'; % Shift zero frequency to center end end function [theta_vals, S_theta] = computeNormalizedAngularSpectralDistribution(IMGFFT, r_min, r_max, num_bins, threshold, sigma) % Apply threshold to isolate strong peaks IMGFFT(IMGFFT < threshold) = 0; % Prepare polar coordinates [ny, nx] = size(IMGFFT); [X, Y] = meshgrid(1:nx, 1:ny); cx = ceil(nx/2); cy = ceil(ny/2); R = sqrt((X - cx).^2 + (Y - cy).^2); Theta = atan2(Y - cy, X - cx); % range [-pi, pi] % Choose radial band radial_mask = (R >= r_min) & (R <= r_max); % Initialize the angular structure factor array S_theta = zeros(1, num_bins); % Pre-allocate for 180 angle bins % Define the angle values for the x-axis theta_vals = linspace(0, pi, num_bins); % Loop through each angle bin for i = 1:180 angle_start = (i-1) * pi / num_bins; angle_end = i * pi / num_bins; % Define a mask for the given angle range angle_mask = (Theta >= angle_start & Theta < angle_end); bin_mask = radial_mask & angle_mask; % Extract the Fourier components for the given angle fft_angle = IMGFFT .* bin_mask; % Integrate the Fourier components over the radius at the angle S_theta(i) = sum(sum(abs(fft_angle).^2)); % sum of squared magnitudes end % Create a 1D Gaussian kernel half_width = ceil(3 * sigma); x = -half_width:half_width; gauss_kernel = exp(-x.^2 / (2 * sigma^2)); gauss_kernel = gauss_kernel / sum(gauss_kernel); % normalize % Apply convolution (circular padding to preserve periodicity) S_theta = conv([S_theta(end-half_width+1:end), S_theta, S_theta(1:half_width)], gauss_kernel, 'same'); S_theta = S_theta(half_width+1:end-half_width); % crop back to original size % Normalize to 1 S_theta = S_theta / max(S_theta); end function ret = getBkgOffsetFromCorners(img, x_fraction, y_fraction) % image must be a 2D numerical array [dim1, dim2] = size(img); s1 = img(1:round(dim1 * y_fraction), 1:round(dim2 * x_fraction)); s2 = img(1:round(dim1 * y_fraction), round(dim2 - dim2 * x_fraction):dim2); s3 = img(round(dim1 - dim1 * y_fraction):dim1, 1:round(dim2 * x_fraction)); s4 = img(round(dim1 - dim1 * y_fraction):dim1, round(dim2 - dim2 * x_fraction):dim2); ret = mean([mean(s1(:)), mean(s2(:)), mean(s3(:)), mean(s4(:))]); end function ret = subtractBackgroundOffset(img, fraction) % Remove the background from the image. % :param dataArray: The image % :type dataArray: xarray DataArray % :param x_fraction: The fraction of the pixels used in x axis % :type x_fraction: float % :param y_fraction: The fraction of the pixels used in y axis % :type y_fraction: float % :return: The image after removing background % :rtype: xarray DataArray x_fraction = fraction(1); y_fraction = fraction(2); offset = getBkgOffsetFromCorners(img, x_fraction, y_fraction); ret = img - offset; end function ret = cropODImage(img, center, span) % Crop the image according to the region of interest (ROI). % :param dataSet: The images % :type dataSet: xarray DataArray or DataSet % :param center: The center of region of interest (ROI) % :type center: tuple % :param span: The span of region of interest (ROI) % :type span: tuple % :return: The cropped images % :rtype: xarray DataArray or DataSet x_start = floor(center(1) - span(1) / 2); x_end = floor(center(1) + span(1) / 2); y_start = floor(center(2) - span(2) / 2); y_end = floor(center(2) + span(2) / 2); ret = img(y_start:y_end, x_start:x_end); end function ret = calculateODImage(imageAtom, imageBackground, imageDark) % Calculate the OD image for absorption imaging. % :param imageAtom: The image with atoms % :type imageAtom: numpy array % :param imageBackground: The image without atoms % :type imageBackground: numpy array % :param imageDark: The image without light % :type imageDark: numpy array % :return: The OD images % :rtype: numpy array numerator = imageBackground - imageDark; denominator = imageAtom - imageDark; numerator(numerator == 0) = 1; denominator(denominator == 0) = 1; ret = -log(double(abs(denominator ./ numerator))); if numel(ret) == 1 ret = ret(1); end end function [optrefimages] = removefringesInImage(absimages, refimages, bgmask) % removefringesInImage - Fringe removal and noise reduction from absorption images. % Creates an optimal reference image for each absorption image in a set as % a linear combination of reference images, with coefficients chosen to % minimize the least-squares residuals between each absorption image and % the optimal reference image. The coefficients are obtained by solving a % linear set of equations using matrix inverse by LU decomposition. % % Application of the algorithm is described in C. F. Ockeloen et al, Improved % detection of small atom numbers through image processing, arXiv:1007.2136 (2010). % % Syntax: % [optrefimages] = removefringesInImage(absimages,refimages,bgmask); % % Required inputs: % absimages - Absorption image data, % typically 16 bit grayscale images % refimages - Raw reference image data % absimages and refimages are both cell arrays containing % 2D array data. The number of refimages can differ from the % number of absimages. % % Optional inputs: % bgmask - Array specifying background region used, % 1=background, 0=data. Defaults to all ones. % Outputs: % optrefimages - Cell array of optimal reference images, % equal in size to absimages. % % Dependencies: none % % Authors: Shannon Whitlock, Caspar Ockeloen % Reference: C. F. Ockeloen, A. F. Tauschinsky, R. J. C. Spreeuw, and % S. Whitlock, Improved detection of small atom numbers through % image processing, arXiv:1007.2136 % Email: % May 2009; Last revision: 11 August 2010 % Process inputs % Set variables, and flatten absorption and reference images nimgs = size(absimages,3); nimgsR = size(refimages,3); xdim = size(absimages(:,:,1),2); ydim = size(absimages(:,:,1),1); R = single(reshape(refimages,xdim*ydim,nimgsR)); A = single(reshape(absimages,xdim*ydim,nimgs)); optrefimages=zeros(size(absimages)); % preallocate if not(exist('bgmask','var')); bgmask=ones(ydim,xdim); end k = find(bgmask(:)==1); % Index k specifying background region % Ensure there are no duplicate reference images % R=unique(R','rows')'; % comment this line if you run out of memory % Decompose B = R*R' using singular value or LU decomposition [L,U,p] = lu(R(k,:)'*R(k,:),'vector'); % LU decomposition for j=1:nimgs b=R(k,:)'*A(k,j); % Obtain coefficients c which minimise least-square residuals lower.LT = true; upper.UT = true; c = linsolve(U,linsolve(L,b(p,:),lower),upper); % Compute optimised reference image optrefimages(:,:,j)=reshape(R*c,[ydim xdim]); end end % Deprecated %% Display Images %{ figure(1) clf set(gcf,'Position',[50 50 950 750]) % Calculate the x and y limits for the cropped image y_min = center(1) - span(2) / 2; y_max = center(1) + span(2) / 2; x_min = center(2) - span(1) / 2; x_max = center(2) + span(1) / 2; % Generate x and y arrays representing the original coordinates for each pixel x_range = linspace(x_min, x_max, span(1)); y_range = linspace(y_min, y_max, span(2)); % Display the cropped image for k = 1 : length(od_imgs) imagesc(x_range, y_range, od_imgs{k}) axis equal tight; hcb = colorbar; hL = ylabel(hcb, 'Optical Density'); set(hL,'Rotation',-90); colormap jet; set(gca,'CLim',[0 3.0]); set(gca,'YDir','normal') set(gca, 'YTick', linspace(y_min, y_max, 5)); % Define y ticks set(gca, 'YTickLabel', flip(linspace(y_min, y_max, 5))); % Flip only the labels xlabel('X', 'Interpreter', 'tex'); ylabel('Y', 'Interpreter', 'tex'); drawnow pause(0.5) end %} %% Angular Distribution %{ function [theta_vals, angular_intensity] = computeAngularDistribution(IMGFFT, r_min, r_max, num_bins, threshold) % Apply threshold to isolate strong peaks IMGFFT(IMGFFT < threshold) = 0; % Prepare polar coordinates [ny, nx] = size(IMGFFT); [X, Y] = meshgrid(1:nx, 1:ny); cx = ceil(nx/2); cy = ceil(ny/2); R = sqrt((X - cx).^2 + (Y - cy).^2); Theta = atan2(Y - cy, X - cx); % range [-pi, pi] % Choose radial band mask = (R >= r_min) & (R <= r_max); % Bin intensities by angle theta_vals = linspace(-pi, pi, num_bins+1); angular_intensity = zeros(1, num_bins); for i = 1:num_bins t0 = theta_vals(i); t1 = theta_vals(i+1); bin_mask = mask & (Theta >= t0) & (Theta < t1); tmp = mean(IMGFFT(bin_mask), 'all'); if tmp > 50 angular_intensity(i) = tmp; else angular_intensity(i) = 0; end end end %}