[Octave] Radon Transform function
function PR = radon(IMG, THETA) %% This MATLAB function takes an image matrix and vector of angles and then %% finds the 1D projection (Radon transform) at each of the angles. It returns %% a matrix whose columns are the projections at each angle. %% %% Written by : Justin K. Romberg % pad the image with zeros so we don't lose anything when we rotate. [iLength, iWidth] = size(IMG); iDiag = sqrt(iLength^2 + iWidth^2); LengthPad = ceil(iDiag - iLength) + 2; WidthPad = ceil(iDiag - iWidth) + 2; padIMG = zeros(iLength+LengthPad, iWidth+WidthPad); padIMG(ceil(LengthPad/2):(ceil(LengthPad/2)+iLength-1), ... ceil(WidthPad/2):(ceil(WidthPad/2)+iWidth-1)) = IMG; % loop over the number of angles, rotate 90-theta (because we can easily sum % if we look at stuff from the top), and then add up. Don't perform any % interpolation on the rotating. n = size(padIMG,1); x = linspace(-1,1,n); [X1,Y1] = meshgrid(x,x); n = length(THETA); PR = zeros(size(padIMG,2), n); for i = 1:n thet...