# Mahotas – RGB to Gray Conversion

• Last Updated : 12 Dec, 2021

In this article we will see how we can convert rgb image to gray in mahotas. An RGB image, sometimes referred to as a truecolor image, is stored in MATLAB as an m-by-n-by-3 data array that defines red, green, and blue color components for each individual pixel.
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.colors.rgb2greymethod

Syntax : mahotas.colors.rgb2gray(img)
Argument :It takes image object as argument
Return : It returns image object

Note : It can convert image to grayscale as using rgb2grey or rgb2gray, both work). This conversion uses a visually realistic method (which weighs the green channel more heavily as human eyes are more sensitive to it)
Below is the implementation

## Python3

 `# importing required libraries``import` `mahotas``import` `mahotas.demos``from` `pylab ``import` `gray, imshow, show``import` `numpy as np`` ` `# loading image``img ``=` `mahotas.demos.load(``'lena'``)` ` ` `# showing image``print``(``"Image"``)``imshow(img)``show()` `# rgb to gray``new_img ``=` `mahotas.colors.rgb2gray(img)` `# showing new image``print``(``"New Image"``)``imshow(new_img)``show()`

Output :

`Image`

`New Image`

Another example

## Python3

 `# importing required libraries``import` `mahotas``import` `numpy as np``import` `matplotlib.pyplot as plt``import` `os`` ` `# loading image``img ``=` `mahotas.imread(``'dog_image.png'``)``      ` `# filtering image``img ``=` `img[:, :, :``3``]` `# showing image``print``(``"Image"``)``imshow(img)``show()` `# rgb to gray``new_img ``=` `mahotas.colors.rgb2gray(img)` `# showing new image``print``(``"New Image"``)``imshow(new_img)``show()`

Output :

`Image`

`New Image`

My Personal Notes arrow_drop_up