pythonscipypolygonsagepoint-in-polygon

SciPy Create 2D Polygon Mask


I need to create a numpy 2D array which represents a binary mask of a polygon, using standard Python packages.

(Larger context: I want to get the distance transform of this polygon using scipy.ndimage.morphology.distance_transform_edt.)

Can anyone show me how to do this?


Solution

  • The answer turns out to be quite simple:

    import numpy
    from PIL import Image, ImageDraw
    
    # polygon = [(x1,y1),(x2,y2),...] or [x1,y1,x2,y2,...]
    # width = ?
    # height = ?
    
    img = Image.new('L', (width, height), 0)
    ImageDraw.Draw(img).polygon(polygon, outline=1, fill=1)
    mask = numpy.array(img)