convert_shape_area.py

import sys
from skimage import io,  color
from scipy.ndimage.measurements import label, sum
from skimage.morphology import convex_hull_image

def main():
    if len(sys.argv) < 4:
        print("Input format: <filename> <minimum size of detected shape in pixels> <threshold between 0 and 1>")
        return

    filename = sys.argv[1]
    minimum_pixel_size = int(sys.argv[2])
    threshold = float(sys.argv[3])

    image = io.imread(filename)
    gray_image = color.rgb2gray(image)
    binary = gray_image < threshold
    segmented, num_segments = label(binary)

    for i in range(1,num_segments+1):
        total_pixels_in_shape = sum(segmented == i)

        if total_pixels_in_shape > minimum_pixel_size:
            convex_hull = convex_hull_image(segmented == i)
            area = sum(convex_hull)
            print("Shape number: " + str(i) +  " shape area (in pixels): " + str(area))


if __name__ == "__main__":
    main()