In this article we will see how we can do stretching for RGB image in mahotas. Contrast stretching (often called normalization) is a simple image enhancement technique that attempts to improve the contrast in an image by `stretching’ the range of intensity values it contains to span a desired range of values, e.g. the full range of pixel values that the image type concerned allows. RGB stretching is variation of stretch() function that works per-channel on an RGB image
In this tutorial we will use “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.regmin method
Syntax : mahotas.stretch_rgb(img)
Argument : It takes image object as argument
Return : It returns image object
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') print("Image") # showing imageimshow(img)show()# stretching rgb imagenew_img = mahotas.stretch_rgb(img) # Stretched imageprint("Stretched Image")imshow(new_img)show() |
Output :
Image
Stretched Image
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') print("Image") # showing imageimshow(img)show()# stretching imagenew_img = mahotas.stretch_rgb(img) # Stretched imageprint("Stretched Image")imshow(new_img)show() |
Output :
Image
Stretched Image
