mirror of
https://github.com/wassname/scikit-image.git
synced 2026-06-29 03:37:34 +08:00
Tony S Yu
79 lines
2.4 KiB
Python
79 lines
2.4 KiB
Python
import functools
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import numpy as np
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from skimage import color
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from skimage.util.dtype import convert
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__all__ = ['adapt_rgb', 'hsv_value', 'each_channel']
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def is_rgb_like(image):
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"""Return True if the image *looks* like it's RGB.
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This function should not be public because it is only intended to be used
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for functions that don't accept volumes as input, since checking an image's
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shape is fragile.
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"""
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return (image.ndim == 3) and (image.shape[2] in (3, 4))
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def adapt_rgb(apply_to_rgb):
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"""Return decorator that adapts to RGB images to a gray-scale filter.
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This function is only intended to be used for functions that don't accept
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volumes as input, since checking an image's shape is fragile.
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Parameters
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----------
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apply_to_rgb : function
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Function that returns a filtered image from an image-filter and RGB
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image. This will only be called if the image is RGB-like.
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"""
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def decorator(image_filter):
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@functools.wraps(image_filter)
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def image_filter_adapted(image, *args, **kwargs):
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if is_rgb_like(image):
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return apply_to_rgb(image_filter, image, *args, **kwargs)
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else:
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return image_filter(image, *args, **kwargs)
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return image_filter_adapted
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return decorator
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def hsv_value(image_filter, image, *args, **kwargs):
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"""Return color image by applying `image_filter` on HSV-value of `image`.
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Note that this function is intended for use with `adapt_rgb`.
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Parameters
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----------
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image_filter : function
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Function that filters a gray-scale image.
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image : array
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Input image. Note that RGBA images are treated as RGB.
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"""
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# Slice the first three channels so that we remove any alpha channels.
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hsv = color.rgb2hsv(image[:, :, :3])
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value = hsv[:, :, 2].copy()
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value = image_filter(value, *args, **kwargs)
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hsv[:, :, 2] = convert(value, hsv.dtype)
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return color.hsv2rgb(hsv)
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def each_channel(image_filter, image, *args, **kwargs):
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"""Return color image by applying `image_filter` on channels of `image`.
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Note that this function is intended for use with `adapt_rgb`.
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Parameters
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----------
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image_filter : function
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Function that filters a gray-scale image.
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image : array
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Input image.
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"""
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c_new = [image_filter(c, *args, **kwargs) for c in image.T]
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return np.array(c_new).T
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