moments_central
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skimage.measure.moments_central(image, cr, cc, order=3)
[source] -
Calculate all central image moments up to a certain order.
The center coordinates (cr, cc) can be calculated from the raw moments as: {
m[0, 1] / m[0, 0]
,m[1, 0] / m[0, 0]
}.Note that central moments are translation invariant but not scale and rotation invariant.
Parameters: image : 2D double or uint8 array
Rasterized shape as image.
cr : double
Center row coordinate.
cc : double
Center column coordinate.
order : int, optional
Maximum order of moments. Default is 3.
Returns: mu : (
order + 1
,order + 1
) arrayCentral image moments.
References
[R269] Wilhelm Burger, Mark Burge. Principles of Digital Image Processing: Core Algorithms. Springer-Verlag, London, 2009. [R270] B. Jähne. Digital Image Processing. Springer-Verlag, Berlin-Heidelberg, 6. edition, 2005. [R271] T. H. Reiss. Recognizing Planar Objects Using Invariant Image Features, from Lecture notes in computer science, p. 676. Springer, Berlin, 1993. [R272] http://en.wikipedia.org/wiki/Image_moment Examples
>>> image = np.zeros((20, 20), dtype=np.double) >>> image[13:17, 13:17] = 1 >>> m = moments(image) >>> cr = m[0, 1] / m[0, 0] >>> cc = m[1, 0] / m[0, 0] >>> moments_central(image, cr, cc) array([[ 16., 0., 20., 0.], [ 0., 0., 0., 0.], [ 20., 0., 25., 0.], [ 0., 0., 0., 0.]])
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