Mahotas – Image Ellipse Axes

In this article we will see how we can get the image ellipse axes in mahotas. Ellipse exes are parameters of the image ellipse, parameters of the constant intensity ellipse with the same mass and second-order moments as the original image.
For this tutorial we will use ‘lena’ image, below is the command to load the lena image
mahotas.demos.load('lena')
Below is the lena image
In order to do this we will use mahotas.features.ellipse_axes method
Syntax : mahotas.features.ellipse_axes(img)
Argument : It takes image object as argument
Return : It returns two float values
Note : Input image should be filtered or should be loaded as grey
In order to filter the image we will take the image object which is numpy.ndarray and filter it with the help of indexing, below is the command to do this
image = image[:, :, 0]
Below is the implementation
Python3
# importing required librariesimport mahotasimport mahotas.demosfrom pylab import gray, imshow, showimport numpy as npimport matplotlib.pyplot as plt # loading imageimg = mahotas.demos.load('lena') # filtering imageimg = img.max(2)print("Image") # showing imageimshow(img)show()# computing Parameters of the ‘image ellipse’semimajor, semiminor = mahotas.features.ellipse_axes(img) # showing valueprint("Semi Major Exes : " + str(semimajor))print("Semi Minor Exes : " + str(semiminor)) |
Output :
Image
Semi Major Exes : 295.60277400592844 Semi Minor Exes : 295.60277400592844
Another example
Python3
# importing required librariesimport mahotasimport numpy as npfrom pylab import gray, imshow, showimport osimport matplotlib.pyplot as plt # loading imageimg = mahotas.imread('dog_image.png')# filtering imageimg = img[:, :, 0] print("Image") # showing imageimshow(img)show()# computing Parameters of the ‘image ellipse’semimajor, semiminor = mahotas.features.ellipse_axes(img) # showing valueprint("Semi Major Exes : " + str(semimajor))print("Semi Minor Exes : " + str(semiminor)) |
Output :
Image
Semi Major Exes : 508.79612573247636 Semi Minor Exes : 308.5809619544451




