samples/python/snippets/logpolar.py

An example using the linearPolar and logPolar operations in python

#!/usr/bin/env python
 
'''
plots image as logPolar and linearPolar
 
Usage:
    logpolar.py
 
Keys:
    ESC    - exit
'''
 
# Python 2/3 compatibility
from __future__ import print_function
 
import numpy as np
import cv2 as cv
 
def main():
    import sys
    try:
        fn = sys.argv[1]
    except IndexError:
        fn = 'fruits.jpg'
 
    img = cv.imread(cv.samples.findFile(fn))
    if img is None:
        print('Failed to load image file:', fn)
        sys.exit(1)
 
    img2 = cv.logPolar(img, (img.shape[0]/2, img.shape[1]/2), 40, cv.WARP_FILL_OUTLIERS)
    img3 = cv.linearPolar(img, (img.shape[0]/2, img.shape[1]/2), 40, cv.WARP_FILL_OUTLIERS)
 
    cv.imshow('before', img)
    cv.imshow('logpolar', img2)
    cv.imshow('linearpolar', img3)
 
    cv.waitKey(0)
    print('Done')
 
 
if __name__ == '__main__':
    print(__doc__)
    main()
    cv.destroyAllWindows()