Bao Ngo asked . 2022-12-15

Output argument (and possibly others) not assigned

Output argument <XX> (and possibly others) not assigned a value in the execution with <YY> function

I have a function script as follows: 

function [h]=getColorHist(im, color_table, opt) 
    im = rgb2hsv(im);   
    [ht,wid,~]=size(im);
    if opt == 'euc' % euclidean distance
    D = pdist2(color_table, reshape(im, [ht*wid, 3]));
    end
end

 f_hist(f_cnt, :) = getColorHist(hsv_im, color_table,'euc')

where HW3.m is:

im_path='/MATLAB Drive/Published/NWPU-RESISC45_1';
ids = {'airplane', 'airport', 'baseball_diamond', 'baseball_court', 'beach','bridge','chaparral', 'church', 'circular_farmland', 'cloud','commercial_area','dense_residental', 'desert', 'forest', 'freeway'};
kColor = 64;
color_table = getHSVColorTable_2(im_path, ids, kColor);
nClass = length(ids); nImg = 40; 
f_hist = zeros(nImg*nClass, kColor);
labels = zeros(nImg*nClass, 1);
f_cnt = 0;

for k=1:nClass
    % list of files
    class_path = sprintf('%s/%s', im_path, ids{k});
    f_list = dir(sprintf('%s/*.jpg', class_path));
    offs = randperm(length(f_list));

    % load random 256 pixels from each images
    if isempty(offs) == 0
        for j=1:nImg
            f_cnt = f_cnt + 1;
            % read in a random image from the class
            im = imread(sprintf('%s/%s', class_path, f_list(offs(j)).name)); 
            hsv_im = rgb2hsv(im);
            f_hist(f_cnt, :) = getColorHist(hsv_im, color_table,'euc');
            labels(f_cnt) = k;
            % plot
            if (1)
                figure(3); subplot(nClass, nImg, f_cnt); 
                plot(f_hist(f_cnt, :)); grid on;
            end
        end
    end 
end

function [color_table]=getHSVColorTable_2(im_path, ids, kColor)
dbg=1;
if dbg
   im_path='/MATLAB Drive/Published/NWPU-RESISC45_1';
   ids = {'airplane', 'airport', 'baseball_diamond', 'baseball_court', 'beach','bridge','chaparral', 'church', 'circular_farmland', 'cloud','commercial_area','dense_residental', 'desert', 'forest', 'freeway'};
   kColor = 64;
end

nClass = length(ids); nImg = 40; nPixelPerImage = 256;

% sample images from the repository to train a global HSV color table
% training pixels
x = zeros(nImg*nPixelPerImage*nClass, 3); cnt = 0; 

for k=1:nClass
    % list of files
    class_path = sprintf('%s/%s', im_path, ids{k});
    f_list = dir(sprintf('%s/*.jpg', class_path));
    offs = randperm(length(f_list));

    % load random 256 pixels from each images
    if isempty(offs) == 0
        for j=1:nImg
            % read in a random image from the class
            im = imread(sprintf('%s/%s', class_path, f_list(offs(j)).name)); 
            hsv_im = rgb2hsv(im); 
            [ht,wid,~] = size(im);
            hsv_im = reshape(hsv_im, [ht*wid, 3]);
            pix_offs = randperm(ht*wid); 
            x(cnt+1:cnt+nPixelPerImage, :) = hsv_im(pix_offs(1:nPixelPerImage), :);
            cnt = cnt + nPixelPerImage;
        end
        % plot
        if dbg
            figure(1); subplot(1, nClass, k); 
            subplot(1, nClass, k); imshow(im); title(ids{k});
        end
    end 
end

color-histogram , Pattern Recognition and Classification , AI, Data Science, and Statistics