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Histogram with bezier curve overlay

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  • PerdrixP Offline
    PerdrixP Offline
    Perdrix
    wrote on last edited by Perdrix
    #1

    Before I disappear down a rabbit hole trying to do something that QtChart won't do, I thought I'd check if QtCharts can do what I want to replicate.

    Below is a histogram with a bezier curve overlay created by some old code that I need to convert to Qt. The histogram displays normalised observation counts against intensity level (0 to 65535) for each of Red Green and Blue, and a gaussian curve for each colour displaying additional information. The bezier curve (black) is conceptually the same as the curve in Photoshop "Curves"

    41e62cb7-c968-480e-bfaa-c4acb9b7dbd5-image.png

    Not quite sure where I'd start with this, guidance will be most welcome.

    I think I may be able to do the red, green and blue "histograms" using QAreaSeries

    Thanks
    David

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    • S Offline
      S Offline
      SimonSchroeder
      wrote on last edited by
      #2

      I personally don't use QtCharts as it is only GPL (or commercial). However, I would expect that it does not understand the concept of bezier curves. Instead, for charts you usually have to provide a list of x/y coordinates. This means you need to sample your bezier curve and provide the sampled points to QtCharts to draw a regular curve.

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      • PerdrixP Offline
        PerdrixP Offline
        Perdrix
        wrote on last edited by
        #3

        I've already got the code to calculate bezier curves and gaussian curves, so they can be handled as line charts.

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