Mahotas – XYZ to LAB Conversion

In image processing, converting an image from one color space to another can be an important step in enhancing or analyzing the image. One common color space used in image processing is the LAB color space, which separates color information into luminance (L) and two color-opponent channels, a and b.

Mahotas is a Python library that includes functions for image processing and analysis. In this tutorial, we will use Mahotas to convert an image from the XYZ color space to the LAB color space.

Prerequisites

To follow along with this tutorial, you will need:

• Python 3
• Mahotas library
• An image in XYZ color space

XYZ Color Space

XYZ is a color space that uses three coordinates to specify a color. The three coordinates are:

• X: the amount of red light in the color.
• Y: the amount of green light in the color.
• Z: the amount of blue light in the color.

LAB Color Space

LAB is a color space that separates color information into luminance (L) and two color-opponent channels, a and b. In the LAB color space:

• L: represents brightness.
• a: represents the red-green axis.
• b: represents the blue-yellow axis.

Conversion Steps

Step 1: Import Libraries

import numpy as np
import mahotas as mh

Step 2: Load Image

# Load XYZ image
xyz_img = mh.imread('xyz_image.png')

Step 3: Convert XYZ to LAB

# Convert XYZ to LAB
lab_img = mh.colors.xyz2lab(xyz_img, illuminant='D50')

The illuminant parameter specifies the white point of the color space. In this case, we use the D50 illuminant, which is commonly used for color matching purposes.

Step 4: Save Image

# Save LAB image
mh.imsave('lab_image.png', lab_img)

Conclusion

In this tutorial, we learned how to use Mahotas to convert an image from the XYZ color space to the LAB color space. By converting an image to a different color space, we can analyze and manipulate the image more effectively.