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    leaflet-multispectral

    0.0.2¬†‚Äʬ†Public¬†‚Äʬ†Published

    Leaflet.Multispectral

    This Leaflet plugin provides multispectral channel manipulation and processing tools (such as NDVI or other remote sensing methods) for Leaflet tile and image layers using pure client-side JavaScript. It uses image-sequencer and was developed by Public Lab.

    It is available as a node module as leaflet-multispectral.

    Also see Leaflet.TileLayer, which is a re-implementation of this library for on-the-fly TileLayer filtering.

    demo.png

    This library was made possible in part by NASA's AREN project.

    Usage

    See the demo for basic usage: https://publiclab.github.io/leaflet-multispectral/

    // create an image
    var img = L.imageOverlay('example.jpg', [[29.0, -118.2],[29.1, -118.4]]);
     
    // apply NDVI equation to the image, and then a colormap:
    img.filter('ndvi,colormap');
     
    img.addTo(map);
     

    To revert the image to it's previous state, use:

    img.revert();

    For more complex commands, you can use JavaScript expresssions, in the following format:

    img.filter('dynamic{red:R*2|green:B|blue:B/2}');

    In this example, we're using Image Sequencer's dynamic module to set the displayed RGB values individually, with the expressions R*2, B, and B/2, respectively.

    Image Sequencer

    Commands you can pass into the filter are extremely flexible; they are Image Sequencer string syntax (full object notation coming soon). Read about Image Sequencer and how to use it here:

    https://github.com/publiclab/image-sequencer

    Using the visual editor, you can develop a command string to pass into this filter:

    https://sequencer.publiclab.org

    Image Sequencer is implemented in pure JavaScript, and is under development; we expect optimizations as well as worker threads and WebAssembly to improve performance in upcoming versions.

    About Multispectral imagery

    Learn about multi-band imagery, some of it's uses at this great blog post by Charlie Lloyd of Mapbox:

    https://blog.mapbox.com/putting-landsat-8s-bands-to-work-631c4029e9d1

    Here's some sources of Landsat 8 data:

    Here's more on NDVI and DIY techniques to collect multi-band imagery: https://publiclab.org/infragram

    Keywords

    none

    Install

    npm i leaflet-multispectral

    DownloadsWeekly Downloads

    0

    Version

    0.0.2

    License

    GPL-3.0

    Unpacked Size

    1.09 MB

    Total Files

    9

    Last publish

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