Mahotas – Creating RGB Image

In this article we will see how we can create a RGB image 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. RGB image can be created with the help of array of each channel.

In order to do this we will use as_rgb method

Syntax : mahotas.as_rgb(r, g, b)

Argument : It takes three numpy array as argument

Return : It returns RGB ndarray object

Below is the implementation

# importing required libraries
import mahotas
import mahotas.demos
from pylab import gray, imshow, show
import numpy as np

# creating array of shape 50x50
# for red channel
r = np.arange(2500).reshape(50, 50)

# for blue channel
g = np.arange(2500).reshape(50, 50)

# for blue channel
b = np.arange(2500).reshape(50, 50)

# making red channel values to 0
r = r * 0

# increasing green channel values
g = g * 100

# making blue channel values to 0
b = b * 0

# creating rgb image from these three channel
img = mahotas.as_rgb(r, g, b)

# showing image
imshow(img)
show()

Output :

Another example

# importing required libraries
import mahotas
import mahotas.demos
from pylab import gray, imshow, show
import numpy as np

# creating numpy linspace
z1 = np.linspace(0, np.pi)

# creating numpy meshgrid
X, Y = np.meshgrid(z1, z1)

# creating rgb channels
# creating red channel through sin function
red = np.sin(X)

# creating green channel through cos function
green = np.cos(4 * Y)

# creating blue channel
blue = X * Y

# creating rgb image from these three channel
img = mahotas.as_rgb(red, green, blue)

# showing image
imshow(img)
show()

Output :