function [k_rho_vals, S_radial] = computeRadialSpectralDistribution(IMGFFT, kx, ky, thetamin, thetamax, num_bins) % IMGFFT : 2D FFT image (fftshifted and cropped) % kx, ky : 1D physical wavenumber axes [μm⁻¹] matching FFT size % thetamin : Minimum angle (in radians) % thetamax : Maximum angle (in radians) % num_bins : Number of radial bins [KX, KY] = meshgrid(kx, ky); K_rho = sqrt(KX.^2 + KY.^2); Theta = atan2(KY, KX); if thetamin < thetamax angle_mask = (Theta >= thetamin) & (Theta <= thetamax); else angle_mask = (Theta >= thetamin) | (Theta <= thetamax); end power_spectrum = abs(IMGFFT).^2; r_min = min(K_rho(angle_mask)); r_max = max(K_rho(angle_mask)); r_edges = linspace(r_min, r_max, num_bins + 1); k_rho_vals = 0.5 * (r_edges(1:end-1) + r_edges(2:end)); S_radial = zeros(1, num_bins); for i = 1:num_bins r_low = r_edges(i); r_high = r_edges(i + 1); radial_mask = (K_rho >= r_low) & (K_rho < r_high); full_mask = radial_mask & angle_mask; S_radial(i) = sum(power_spectrum(full_mask)); end end