How to read/ load .seg file ?

I need to compare image segmentation result with ground truth wich is a .seg extenion file. How can I load this and create image groud truth. A part of the .seg file is shown below (I converted it to text file):

format ascii cr
date Thu Apr 26 17:39:26 2001
image 2092
user 1113
width 481
height 321
segments 9
gray 0
invert 0
flipflop 0
data
0 0 0 480
0 1 0 480
0 2 0 480
0 3 0 480
0 4 0 480
0 5 0 480
0 6 0 480
0 7 0 480
0 8 0 480
0 9 0 480
0 10 0 480
0 11 0 480
0 12 0 480
0 13 0 480
0 14 0 480
0 15 0 480
0 16 0 480
0 17 0 480

[Adriana Royuela]

Hi! I have the same problem. How did you end up doing it?

Answer 1

[Samay Sagar]

Hi @Ynne @Adriana Royuela,

You can parse the data from the segmentation file to extract relevant metadata and segmentation data. The parsed data can be used to create an image matrix. This matrix can be used to generate the ground truth image and can be used for comparison with the segmentation result.

You can use "fgetl" to read the SEG file line by line to extract the corresponding data. Based on the file shared by you, you can follow this approach to parse it:

function groundTruthImage = loadSegFile(filename)
    % Open the file
    fid = fopen(filename, 'r');
    
    % Read the file line by line
    tline = fgetl(fid);
    while ischar(tline)
        % Extract the width and height
        if startsWith(tline, 'width')
            width = sscanf(tline, 'width %d');
        elseif startsWith(tline, 'height')
            height = sscanf(tline, 'height %d');
        elseif strcmp(tline, 'data')
            break;
        end
        tline = fgetl(fid);
    end
    
    % Initialize the ground truth image
    groundTruthImage = zeros(height, width);
    
    % Read the segment data
    while ischar(tline)
        tline = fgetl(fid);
        if ischar(tline)
            data = sscanf(tline, '%d %d %d %d');
            if numel(data) == 4
                row = data(1) + 1; 
                colStart = data(3) + 1;
                colEnd = data(4) + 1;
                groundTruthImage(row, colStart:colEnd) = 1;  % Assuming binary segmentation
            end
        end
    end
    
    % Close the file
    fclose(fid);
end

groundTruthImage = loadSegFile('test.seg');
% Display the ground truth image
imshow(groundTruthImage);
% Now, you can compare this with your segmentation result

For more information, you can refer the following documentations:

"fgetl" : https://www.mathworks.com/help/releases/R2024b/matlab/ref/fgetl.html

"fopen" : https://www.mathworks.com/help/releases/R2024b/matlab/ref/fopen.html