Image.normhist#

Image.normhist() → Image[source]#

Histogram normalisaton

Returns:: normalised image
Return type:: Image instance

Return a histogram normalized version of the image which highlights image detail in low-contrast areas of an image.

Example:

>>> from machinevisiontoolbox import Image
>>> img = Image([[10, 20, 30], [40, 41, 42], [70, 80, 90]])
>>> img.normhist().A
array([[  0,  32,  64],
       [ 96, 128, 159],
       [191, 223, 255]], dtype=uint8)

Note

The histogram of the normalized image is approximately uniform, that is, all grey levels ae equally likely to occur.
Color images automatically converted to greyscale

References:

P. Corke, Robotics, Vision & Control for Python, Springer, 2023, Section 11.3.

Important

Uses OpenCV function cv2.equalizeHist which accepts single-channel, CV_8U images.

Seealso:: cv2.equalizeHist