geopdf_cal.py

#!/bin/env python
import re

class Coordinate(object):
    def __init__(self, x, y):
        self.x = x
        self.y = y
    def __str__(self):
        return "({:.7},{:.7})".format(self.x, self.y)

def main(filename):
    
    geo_regex = re.compile('/GPTS *\[(.*?)]')
    with open(filename, 'rb') as f:
        for l in f.readlines():
            m = geo_regex.search(str(l))
            if m:
                geo_str = m.group(1)
                break
        else:
            raise Exception("Coult not find /GPTS flag in data")
            
    geo_str = geo_str.strip()
    #print(geo_str)

    geo = [float(x) for x in geo_str.split(" ")]
    #viewport = [float(x) for x in viewport_str.split(" ")]
    #box = [float(x) for x in box_str.split(" ")]

    print(geo)
    print("\n\n")

    #width = box[2]
    #height = box[3]
    #topLeftPct = PercentCoordinate(viewport[0] / width, 1 - viewport[1] / height)
    #bottomRightPct = PercentCoordinate(viewport[2] / width, 1 - viewport[3] / height)
    topLeft = Coordinate(geo[0], geo[1])
    bottomRight = Coordinate(geo[6], geo[7])

    print("top left", topLeft)
    print("")
    print("bottom right", bottomRight)

    #MapCalibrationPoint(topLeft, topLeftPct)
    #MapCalibrationPoint(bottomRight, bottomRightPct)

if __name__ == "__main__":
    import argparse
    parser = argparse.ArgumentParser(description='Get cal data from geoPDF')
    parser.add_argument('file', type=str, 
                        help='filename')

    args = parser.parse_args()
    
    main(filename=args.file)