Files
scikit-image/skimage/viewer/utils/core.py
T

119 lines
3.9 KiB
Python

import warnings
import numpy as np
try:
import matplotlib.pyplot as plt
from matplotlib.colors import LinearSegmentedColormap
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg
except ImportError:
FigureCanvasQTAgg = object # hack to prevent nosetest and autodoc errors
LinearSegmentedColormap = object
print("Could not import matplotlib -- skimage.viewer not available.")
try:
from PyQt4 import QtGui
except ImportError:
print("Could not import PyQt4 -- skimage.viewer not available.")
__all__ = ['figimage', 'LinearColormap', 'ClearColormap', 'MatplotlibCanvas',
'RequiredAttr']
class RequiredAttr(object):
"""A class attribute that must be set before use."""
def __init__(self, msg):
self.msg = msg
self.val = None
def __get__(self, obj, objtype):
if self.val is None:
warnings.warn(self.msg)
return self.val
def __set__(self, obj, val):
self.val = val
def figimage(image, scale=1, dpi=None, **kwargs):
"""Return figure and axes with figure tightly surrounding image.
Unlike pyplot.figimage, this actually plots onto an axes object, which
fills the figure. Plotting the image onto an axes allows for subsequent
overlays of axes artists.
Parameters
----------
image : array
image to plot
scale : float
If scale is 1, the figure and axes have the same dimension as the
image. Smaller values of `scale` will shrink the figure.
dpi : int
Dots per inch for figure. If None, use the default rcParam.
"""
dpi = dpi if dpi is not None else plt.rcParams['figure.dpi']
kwargs.setdefault('interpolation', 'nearest')
kwargs.setdefault('cmap', 'gray')
h, w, d = np.atleast_3d(image).shape
figsize = np.array((w, h), dtype=float) / dpi * scale
fig, ax = plt.subplots(figsize=figsize, dpi=dpi)
fig.subplots_adjust(left=0, bottom=0, right=1, top=1)
ax.set_axis_off()
ax.imshow(image, **kwargs)
return fig, ax
class LinearColormap(LinearSegmentedColormap):
"""LinearSegmentedColormap in which color varies smoothly.
This class is a simplification of LinearSegmentedColormap, which doesn't
support jumps in color intensities.
Parameters
----------
name : str
Name of colormap.
segmented_data : dict
Dictionary of 'red', 'green', 'blue', and (optionally) 'alpha' values.
Each color key contains a list of `x`, `y` tuples. `x` must increase
monotonically from 0 to 1 and corresponds to input values for a mappable
object (e.g. an image). `y` corresponds to the color intensity.
"""
def __init__(self, name, segmented_data, **kwargs):
segmented_data = dict((key, [(x, y, y) for x, y in value])
for key, value in segmented_data.iteritems())
LinearSegmentedColormap.__init__(self, name, segmented_data, **kwargs)
class ClearColormap(LinearColormap):
"""Color map that varies linearly from alpha = 0 to 1
"""
def __init__(self, rgb, max_alpha=1, name='clear_color'):
r, g, b = rgb
cg_speq = {'blue': [(0.0, b), (1.0, b)],
'green': [(0.0, g), (1.0, g)],
'red': [(0.0, r), (1.0, r)],
'alpha': [(0.0, 0.0), (1.0, max_alpha)]}
LinearColormap.__init__(self, name, cg_speq)
class MatplotlibCanvas(FigureCanvasQTAgg):
"""Canvas for displaying images."""
def __init__(self, parent, figure, **kwargs):
self.fig = figure
FigureCanvasQTAgg.__init__(self, self.fig)
FigureCanvasQTAgg.setSizePolicy(self,
QtGui.QSizePolicy.Expanding,
QtGui.QSizePolicy.Expanding)
FigureCanvasQTAgg.updateGeometry(self)
# Note: `setParent` must be called after `FigureCanvasQTAgg.__init__`.
self.setParent(parent)