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Thread: Google map on QwtPlotSpectrogram

  1. #1
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    Default Google map on QwtPlotSpectrogram

    Hello,

    I am implementing an application displaying Google map and other location information
    such as grid, and markers in multiple layers with different transparencies. What I tried was to plot Google map on QwtPlotSpectrum. Howerver, I couldn't control the transparency using setAlpha().
    If anyone have an experience of similar application (mixing an image and QwtPlotItem(s)), please share the experience with a short example.

    Thanks in advance.

  2. #2
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    Default Re: Google map on QwtPlotSpectrogram

    QwtPlotSpectrogram is the wrong type of plot item - it's base class QwtPlotRasterItem is what you are looking for. What you need to do is to implement QwtPlotRasterItem::renderImage(). The you can control the alpha value with QwtPlotRasterItem::setAlpha().

    Uwe

  3. The following user says thank you to Uwe for this useful post:

    d_stranz (1st March 2011)

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    Default Re: Google map on QwtPlotSpectrogram

    thank you Uwe.

    although there are more things to do, i was able to display a map with control of alpha as shown attached screenshot.
    Attached Images Attached Images

  5. The following user says thank you to sagittager for this useful post:

    d_stranz (1st March 2011)

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    Default Re: Google map on QwtPlotSpectrogram

    Now this is very cool. It gets me thinking about all kinds of new possibilities.

  7. #5
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    Default Re: Google map on QwtPlotSpectrogram

    This is cool,can you guide us how you went about it! Considering me a newbie


    Thanks

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