histogram

histogram

skimage.exposure.histogram(image, nbins=256) [source]

Return histogram of image.

Unlike numpy.histogram, this function returns the centers of bins and does not rebin integer arrays. For integer arrays, each integer value has its own bin, which improves speed and intensity-resolution.

The histogram is computed on the flattened image: for color images, the function should be used separately on each channel to obtain a histogram for each color channel.

Parameters:	image : array Input image. nbins : int Number of bins used to calculate histogram. This value is ignored for integer arrays.
Returns:	hist : array The values of the histogram. bin_centers : array The values at the center of the bins.

See also

cumulative_distribution

Examples

>>> from skimage import data, exposure, img_as_float
>>> image = img_as_float(data.camera())
>>> np.histogram(image, bins=2)
(array([107432, 154712]), array([ 0. ,  0.5,  1. ]))
>>> exposure.histogram(image, nbins=2)
(array([107432, 154712]), array([ 0.25,  0.75]))