In this article, we will see how we can do the skeletonization of images by thinning in mahotas. Skeletonization is a process for reducing foreground regions in a binary image to a skeletal remnant that largely preserves the extent and connectivity of the original region while throwing away most of the original foreground pixels. Thinning is a morphological operation that is used to remove selected foreground pixels from binary images, somewhat like erosion or opening.
In this tutorial, we will use the “Lena” image, below is the command to load it.
mahotas.demos.load('lena')
Below is the Lena image
In order to do this we will use mahotas.thin method
Syntax : mahotas.thin(img)
Argument : It takes image object as argument
Return : It returns image object
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 np # loading imageimg = mahotas.demos.load('lena') # filtering imageimg = img.max(2)# otsu methodT_otsu = mahotas.otsu(img) # image values should be greater than otsu valueimg = img > T_otsu print("Image threshold using Otsu Method")# showing imageimshow(img)show()# Skeletonisation by thinningnew_img = mahotas.thin(img) # showing imageprint("Skeletonised Image")imshow(new_img)show() |
Output :
Image threshold using Otsu Method
Skeletonised Image
Another example
Python3
# importing required librariesimport mahotasimport numpy as npfrom pylab import gray, imshow, showimport os # loading imageimg = mahotas.imread('dog_image.png')# filtering imageimg = img[:, :, 0] # otsu methodT_otsu = mahotas.otsu(img) # image values should be greater than otsu valueimg = img > T_otsu print("Image threshold using Otsu Method") # showing imageimshow(img)show()# Skeletonisation by thinningnew_img = mahotas.thin(img) # showing imageprint("Skeletonised Image")imshow(new_img)show() |
Output :
Image threshold using Otsu Method
Skeletonised Image
