In this article we will see how we can set the element structure of the dilate of image in mahotas. Dilation adds pixels to the boundaries of objects in an image, while erosion removes pixels on object boundaries. The number of pixels added or removed from the objects in an image depends on the size and shape of the structuring element used to process the image. In order to dilate the image we use mahotas.morph.dilate method.By setting element structure we can increase or decrease the dilating effect on the 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
Implementation steps :
1. Load the image
2. Filter the image
3. Use otsu method for threshold of the image
4. Create a structure of the element with the help of numpy ndarray for binary values
5. Use the element for dilating the image
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() # erode structurees = np.array([ [1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]], bool)# dilating imagedilate_img = mahotas.morph.dilate(img, es) # showing dilated imageprint("Dilated Image")imshow(dilate_img)show() |
Output :
Image threshold using Otsu Method
Dilated 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()# erode structurees = np.array([ [1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]], bool)# dilating imagedilate_img = mahotas.morph.dilate(img, es) # showing dilated imageprint("Dilated Image")imshow(dilate_img)show() |
Output :
Image threshold using Otsu Method
Dilated Image
