CONTACT

Link to Sergei’s ResearchGate profile (link).

Please, leave your comment below.

 

19 Replies to “CONTACT”

  1. Dear Sergei,

    I am using LEFA for the my research work and following error is observed while running the fractal dimension Go command…

    Reference to non-existent field ‘CoordinateSystemType’.

    Error in Linear_structures>pushbutton17_Callback (line 1205)
    switch Reference.CoordinateSystemType

    Error in gui_mainfcn (line 96)
    feval(varargin{:});

    Error in Linear_structures (line 46)
    gui_mainfcn(gui_State, varargin{:});

    Error in
    @(hObject,eventdata)Linear_structures(‘pushbutton17_Callback’,hObject,eventdata,guidata(hObject))

    Error while evaluating uicontrol Callback

    I a using MATLAB 2017a version and what should be the Projection of the DEM.

    Please let me know if any issue from my side.

    Thanks and Regards

    Cheers
    Rakesh

    1. Dear Rakesh,
      Have you succeeded of same operation with testing dataset?
      If answer is “yes”, it looks like, your DEM (probably) has no readable projection.
      Output of Minkowski fractal dimension coverage requires it.
      Please, try Georeferenced DEM data (for instance from glcf.umd.edu) as an alternative. Mind the necessity of edge detection before.
      Keep in touch.
      Regards.
      P.S. your Geotiff should be opened as Geotiff, not the picture. Thanks for your feedback.

  2. Hello Sergei,

    we have downloaded your matlab tool for lineament extraction.

    We did a very quick test with a high resolution DEM but we only manage to extract short lines and they are not what we would map by eye on the DEM. For sure we need to adjust the parameters.

    I have seen that you have an article related to the LEFA tool but…I only find a russian version. Do you have somewhere an explanation in English?

    Thanks,

    Benedetta

    1. Yeah, there is an English guide reference on this website. In the sample folder you may find both SRTM data and corresponding ESRI shape output. So, you can adjust image preprocessing, filters and parameters of extraction for relevant output. I hope, it will help.

  3. Dear Dr Shevyrev

    I congratulate you, for your work, your tool makes interpretation much easier, I have used the two versions pylefa and lefa for matlab. In the first one , it is a little more delayed but does not generate inconveniences. on the other hand, in the version of matlab, I always get this error:

    Error in matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)Linear_structures(‘pushbutton25_Callback’,hObject,eventdata,guidata(hObject))

    Error while evaluating UIControl Callback

    I have used matlab 2020 and 2017, the images have been SRTM, landsat and palsar in projected system utm wgs 84 not in GCS geographic system. Similarly, when I using your sample files, the software also get the same error message discussed above. I have windows 11

    I would very much appreciate your valuable feedback

    Greetings from Ecuador – South America

    Ivan Villarreal

    1. Dear Ivan,
      Please, admit my regrets for that inconvenience. Unfortunately, I do not support LEFA for Matlab version starting 2013a for Windows 7. That’s because my institution does not get campus license anymore. I could only recommend for you to roll back towards version 2013.
      Do you get any error in pyLEFA?

      1. Sergei

        Thank you very much for your reply. I will take into account the Matlab version.

        In pyLefa, I’ve really had no problems, it’s a bit slower, for obvious reasons, but it works!. The identification of lineaments does differ according to the range of the images that are input (in height) but in short, you have developed a spectacular tool. Again I send you my sincere congratulations for your effort. Great job.

        Best regards

        Ivan Villarreal

  4. Dear Sergei

    At pyLEFA, I have had no problems, really, you have done a great job developing an interesting tool.
    The identification of the lineaments depends a lot on the height that the image is considered. but in general it is a very good tool for approximation and identification

    Congratulations

    Best regards

    Ivan Villarreal

  5. Сергей, здравствуйте. Хотел бы выразить благодарность за создание столь полезной программы и обратится к вам за помощью. При создание карты плотности (lineaments density counter) выходят следующие ошибки:
    Error using /
    Matrix dimensions must agree.
    Error in shp_line_dens (line 20)
    col_count=floor(LX/win_size);
    Error in Linear_structures>pushbutton25_Callback (line 286)
    density_mat=shp_line_dens(win_size);
    Error in gui_mainfcn (line 96)
    feval(varargin{:});
    Error in Linear_structures (line 46)
    gui_mainfcn(gui_State, varargin{:});
    Error in @(hObject,eventdata)Linear_structures(‘pushbutton25_Callback’,hObject,eventdata,guidata(hObject))
    Error while evaluating uicontrol Callback
    Могли бы вы подсказать с чем они могут быть связаны?

    1. Dear Dmitri,
      Firstly, I would like to thank you for your interest to my simple software. I really appreciate it.
      Secondly, I suppose that you tried LEFA for Matlab.
      According to error details you have provided, it is related to your Matlab version. LEFA for Matlab for developed for version 2013b. Later releases may not support this software. So, I recommend you to try pyLEFA or rollback to Matlab 2013b.
      Regards, Sergei

      1. Dear Sergei,
        I am using 2013b version. In your guide it says “This feature is available when line array was extracted from image”. Maybe i need to do something, before getting density map?

        1. I don’t support this version for several years. Could you kindly describe the data you process? Are they in geographic of projected coordinate system? Also, prior to compute density map you need to extract linear elements to be shown in a map window. Did you extract lineaments before computing density map (that means performing step 4.1 or 4.2) and get lines on a map?

          1. I am using Landsat-8 images and going straight according to the guide. Firstly i preprocess image with Canny algorithm, the i use Hough algorithm, and in the end joining lines.

  6. I am using Landsat-8 images and going straight according to the guide. Firstly i preprocess image with Canny algorithm, then use Hough algorithm and in the end join lines.

    1. Can your version of LEFA for Matlab perform all of the steps with testing datasets (available on this website)?
      Due to depreciation of LEFA for Matlab I strongly encourage you to try to switch to pyLEFA. pyLEFA doesn’t require preinstalled software (besides of Windows) and is able to compute lineament density map.

      1. I used a test file to create a density map and had a similar problem with it. Thanks for the advice, I’ll try pyLEFA

        1. You are welcome. Nonetheless, LEFA for Matlab was test with dataset, errors could be risen due to operational system or regional settings. Please, keep me updated if problem was resolved.

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