build_reference_table.py

#!/usr/bin/env python

__author__ = "Adeel Ahmad"
__email__ = "adeelahmad14@hotmail.com"
__status__ = "Production"

import numpy as np
from scipy.ndimage import convolve
from skimage import io
import matplotlib.pyplot as plt


def buildRefTable(img):
    """
    builds the reference table for the given input template image
    :param im: input binary image
    :return:
        table = a reconstructed reference table...
    """
    table = [[0 for x in range(1)] for y in range(90)]  # creating a empty list
    # r will be calculated corresponding to this point
    img_center = [int(img.shape[0]/2), int(img.shape[1]/2)]

    def findAngleDistance(x1, y1):
        x2, y2 = img_center[0], img_center[1]
        r = [(x2-x1), (y2-y1)]
        if (x2-x1 != 0):
            return [int(np.rad2deg(np.arctan(int((y2-y1)/(x2-x1))))), r]
        else:
            return [0, 0]

    filter_size = 3
    for x in range(img.shape[0]-(filter_size-1)):
        for y in range(img.shape[1]-(filter_size-1)):
            if (img[x, y] != 0):
                theta, r = findAngleDistance(x, y)
                if (r != 0):
                    table[np.absolute(theta)].append(r)

    for i in range(len(table)):
        table[i].pop(0)

    return table