machinevisiontoolbox.Image.zssd

Image.zssd(image2)

Zero-mean sum of squared differences

Parameters:

image2 (Image) – second image

Raises:

ValueError – image2 shape is not equal to self

Returns:

sum of squared differences

Return type:

scalar

Returns a simple image disimilarity measure which is the zero-mean sum of the squared differences between the image and image2. The result is a scalar and a value of 0 indicates identical pixel patterns (relative to their maen) and is increasingly positive as image dissimilarity increases.

Example:

>>> from machinevisiontoolbox import Image
>>> img1 = Image([[10, 11], [12, 13]])
>>> img2 = Image([[10, 11], [10, 13]])
>>> img1.zssd(img2)
3.0
>>> img1.zssd(img2+10)
3.0
>>> img1.zssd(img2*2)
13.0

Note:

• The zssd similarity measure is invariant to changes in image brightness offset.

References:

• Robotics, Vision & Control for Python, Section 11.5.2, P. Corke, Springer 2023.

Seealso:

zssd sad ncc