mirror of
https://github.com/wassname/scikit-image.git
synced 2026-06-30 00:49:28 +08:00
Olivier Debeir
48 lines
1.3 KiB
Python
48 lines
1.3 KiB
Python
"""
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=====================
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Local Autolevel
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=====================
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Local autolevel stretch local histogram between 0 and max_graylevel (e.g. 255 for 8 bit image).
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The following code shows the difference between autolevel and percentile auto_level where [min,max] interval
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is replaced by [p0,p1] percentiles interval
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"""
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import matplotlib.pyplot as plt
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import numpy as np
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from skimage import data
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from skimage.rank import percentile_autolevel,autolevel
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from skimage.morphology import disk
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image = data.camera()
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selem = disk(20)
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loc_autolevel = autolevel(image,selem=selem)
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loc_perc_autolevel0 = percentile_autolevel(image,selem=selem,p0=.00,p1=1.0)
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loc_perc_autolevel1 = percentile_autolevel(image,selem=selem,p0=.01,p1=.99)
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loc_perc_autolevel2 = percentile_autolevel(image,selem=selem,p0=.05,p1=.95)
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loc_perc_autolevel3 = percentile_autolevel(image,selem=selem,p0=.1,p1=.9)
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loc_perc_autolevel = np.hstack((loc_perc_autolevel0,loc_perc_autolevel1,loc_perc_autolevel2,loc_perc_autolevel3))
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fig, axes = plt.subplots(nrows=3, figsize=(7, 8))
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ax0, ax1, ax2 = axes
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plt.gray()
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ax0.imshow(image)
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ax0.set_title('Image')
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ax1.imshow(loc_autolevel)
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ax1.set_title('Autolevel')
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ax2.imshow(loc_perc_autolevel,vmin=0,vmax=255)
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ax2.set_title('percentile autolevel 0%,1%,5% and 10%')
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for ax in axes:
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ax.axis('off')
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plt.show()
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