In this article we will see how we can perform opening on the image in mahotas. Opening is a process in which first erosion operation is performed and then dilation operation is performed. It eliminates the thin protrusions of the obtained image and it is used for removing internal noise of the obtained image.
In this tutorial we will use “luispedro” image, below is the command to load it.
mahotas.demos.load('luispedro')
Below is the luispedro image
In order to do this we will use mahotas.morph.openmethod
Syntax : mahotas.morph.open(image)
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 imageluispedro = mahotas.demos.load('luispedro') # filtering imageluispedro = luispedro.max(2) # otsu methodT_otsu = mahotas.otsu(luispedro) # image values should be greater than otsu valueimg = luispedro > T_otsu print("Image threshold using Otsu Method") # showing imageimshow(img)show()# opening imagenew_img = mahotas.morph.open(img) # showing new imageprint("Opened Image")imshow(new_img)show() |
Output :
Image threshold using Otsu Method
Opened Image
Another example
Python3
# importing required librariesimport mahotasimport numpy as npimport matplotlib.pyplot as pltimport os # loading imageimg = mahotas.imread('dog_image.png') # setting filter to the imageimg = img[:, :, 0]# otsu methodT_otsu = mahotas.otsu(img) # image values should be greater than otsu valueimg = img > T_otsuprint("Image threshold using Otsu Method")# showing imageimshow(img)show()# opening imagenew_img = mahotas.morph.open(img) # showing new imageprint("Opened Image")imshow(new_img)show() |
Output :
Image threshold using Otsu Method
Opened Image
