Gamma#

class augraphy.augmentations.gamma.Gamma(gamma_range=(0.5, 1.5), p=1)[source]#

Bases: Augmentation

Adjusts the gamma of the whole image by a chosen multiplier.

Parameters:

gamma_range (tuple, optional) – Pair of ints determining the range from which to sample the gamma shift.
p (float, optional) – The probability that this Augmentation will be applied.

Overview#

The Gamma augmentation randomly applies gamma correction (from a range of values) on the image but a gamma value of 1 will not affect the image.

Initially, a clean image with single line of text is created.

Code example:

# import libraries
import cv2
import numpy as np
from augraphy import *


# create a clean image with single line of text
image = np.full((500, 1500,3), 250, dtype="uint8")
cv2.putText(
    image,
    "Lorem ipsum dolor sit amet, consectetur adipiscing elit",
    (80, 250),
    cv2.FONT_HERSHEY_SIMPLEX,
    1.5,
    0,
    3,
)

cv2.imshow("Input image", image)

Clean image:

Example 1#

In this example, a Gamma augmentation instance is initialized and the gamma range is set to random value between 2 to 3 times of existing gamma (2,3).

Code example:

gamma = Gamma(gamma_range=(2.0, 3.0))

img_gamma= gamma(image)
cv2.imshow("gamma", img_gamma)

Augmented image: