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Line Tracer/Digitizer

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  • mrjjM mrjj

    @ParanoidAndroid
    Ok and are those lines straight or more like a spline / curve ?
    if just a line then
    https://www.geeksforgeeks.org/program-find-line-passing-2-points/

    but since you asked for help i assume its something more complicated ?

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    ParanoidAndroid
    wrote on last edited by
    #5

    @mrjj They can be any 2D line graph splines, straight, lines curves

    mrjjM 1 Reply Last reply
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    • P ParanoidAndroid

      @mrjj They can be any 2D line graph splines, straight, lines curves

      mrjjM Offline
      mrjjM Offline
      mrjj
      Lifetime Qt Champion
      wrote on last edited by
      #6

      @ParanoidAndroid
      Ok. so we need the data these
      2D line graph splines, straight, lines curves are based on if we are to calculate its
      function based on a few points.

      Can i see one images with the drawn curves you wish to calculate ?

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      • P Offline
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        ParanoidAndroid
        wrote on last edited by
        #7

        Here is an example of the splineGraph3.png

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        • kshegunovK Offline
          kshegunovK Offline
          kshegunov
          Moderators
          wrote on last edited by
          #8

          You need to read math, I'm afraid. Rational B-splines, normal cubic splines or polyharmonic splines could work in your case, however I leave the wikipedia-ing to you. ;)

          Read and abide by the Qt Code of Conduct

          P 1 Reply Last reply
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          • kshegunovK kshegunov

            You need to read math, I'm afraid. Rational B-splines, normal cubic splines or polyharmonic splines could work in your case, however I leave the wikipedia-ing to you. ;)

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            ParanoidAndroid
            wrote on last edited by
            #9

            @kshegunov
            Is there no way to say track the colour of the spline and give pixel coordinates

            kshegunovK 1 Reply Last reply
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            • P ParanoidAndroid

              @kshegunov
              Is there no way to say track the colour of the spline and give pixel coordinates

              kshegunovK Offline
              kshegunovK Offline
              kshegunov
              Moderators
              wrote on last edited by
              #10

              Sorry, I don't understand the question. Please rephrase.

              Read and abide by the Qt Code of Conduct

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              • kshegunovK kshegunov

                Sorry, I don't understand the question. Please rephrase.

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                ParanoidAndroid
                wrote on last edited by
                #11

                @kshegunov instead of using mathematics could you say click to select the colour of the line and then have the application give the coordinates of every pixel connected with that colour

                mrjjM 1 Reply Last reply
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                • P ParanoidAndroid

                  @kshegunov instead of using mathematics could you say click to select the colour of the line and then have the application give the coordinates of every pixel connected with that colour

                  mrjjM Offline
                  mrjjM Offline
                  mrjj
                  Lifetime Qt Champion
                  wrote on last edited by
                  #12

                  @ParanoidAndroid
                  Hi
                  If all images are as clean as this, you can easily scan to find the blue color and hence the Y coordinate.
                  https://doc.qt.io/qt-5/qimage.html#pixel-1
                  or the faster way
                  https://doc.qt.io/qt-5/qimage.html#scanLine

                  But it wont be fast as such but unless
                  tiny mini board it should be fine:)

                  P 1 Reply Last reply
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                  • mrjjM mrjj

                    @ParanoidAndroid
                    Hi
                    If all images are as clean as this, you can easily scan to find the blue color and hence the Y coordinate.
                    https://doc.qt.io/qt-5/qimage.html#pixel-1
                    or the faster way
                    https://doc.qt.io/qt-5/qimage.html#scanLine

                    But it wont be fast as such but unless
                    tiny mini board it should be fine:)

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                    P Offline
                    ParanoidAndroid
                    wrote on last edited by
                    #13

                    @mrjj thankyou for your help. Will this give an x coordinate aswell

                    jsulmJ 1 Reply Last reply
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                    • P ParanoidAndroid

                      @mrjj thankyou for your help. Will this give an x coordinate aswell

                      jsulmJ Offline
                      jsulmJ Offline
                      jsulm
                      Lifetime Qt Champion
                      wrote on last edited by
                      #14

                      @ParanoidAndroid said in Line Tracer/Digitizer:

                      Will this give an x coordinate aswell

                      Just iterate over all x coordinates and search for y like @mrjj suggested. Or iterate over y and get x...

                      https://forum.qt.io/topic/113070/qt-code-of-conduct

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