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# /*##########################################################################
#
# The PyMca X-Ray Fluorescence Toolkit
#
# Copyright (c) 2004-2020 European Synchrotron Radiation Facility
#
# This file is part of the PyMca X-ray Fluorescence Toolkit developed at
# the ESRF by the Software group.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
# ###########################################################################*/
__author__ = "T. Vincent - ESRF Data Analysis"
__contact__ = "thomas.vincent@esrf.fr"
__license__ = "MIT"
__copyright__ = "European Synchrotron Radiation Facility, Grenoble, France"
__doc__ = """Convert data to a RGBA colormap."""
# import ######################################################################
import numpy as np
from . import ctools
# default colormaps ###########################################################
_CMAP_RED = np.zeros((256, 4), dtype=np.uint8)
_CMAP_RED[:, 0] = np.arange(256, dtype=np.uint8)
_CMAP_RED[:, 3] = 255
_CMAP_GREEN = np.zeros((256, 4), dtype=np.uint8)
_CMAP_GREEN[:, 1] = np.arange(256, dtype=np.uint8)
_CMAP_GREEN[:, 3] = 255
_CMAP_BLUE = np.zeros((256, 4), dtype=np.uint8)
_CMAP_BLUE[:, 2] = np.arange(256, dtype=np.uint8)
_CMAP_BLUE[:, 3] = 255
_CMAP_BLUE = np.zeros((256, 4), dtype=np.uint8)
_CMAP_BLUE[:, 2] = np.arange(256, dtype=np.uint8)
_CMAP_BLUE[:, 3] = 255
_CMAP_GRAY = np.indices((256, 4), dtype=np.uint8)[0]
_CMAP_GRAY[:, 3] = 255
_CMAP_REVERSED_GRAY = 255 - np.indices((256, 4), dtype=np.uint8)[0]
_CMAP_REVERSED_GRAY[:, 3] = 255
_INDICES = np.arange(256, dtype=np.int)
_CMAP_TEMPERATURE = np.asarray(np.dstack((
np.interp(_INDICES, (128, 192), (0, 255)),
np.interp(_INDICES, (0, 64, 192, 255), (0, 255, 255, 0)),
np.interp(_INDICES, (64, 128), (255, 0)),
np.array((255,) * 256)))[0], dtype=np.uint8, order='C')
"""
red: For index 128->192, red is 0->255
green: For index 0->64, green is 0->255 and for 192->255, green is 255->0
blue: For index 64->128, blue is 255->0
"""
COLORMAPS = {
# Sequential
'red': _CMAP_RED,
'green': _CMAP_GREEN,
'blue': _CMAP_BLUE,
'gray': _CMAP_GRAY,
'reversed gray': _CMAP_REVERSED_GRAY,
# Rainbow
'temperature': _CMAP_TEMPERATURE,
}
"""Dictionary of default colormaps."""
# colormap ####################################################################
def applyColormap(data, colormap='gray', norm='linear', bounds=None):
"""Convert data to a RGBA pixmap using a colormap.
The returned pixmap has the same shape as data plus one dimension of 4.
:param numpy.ndarray data: The data to convert to a pixmap.
Any dimension is supported.
:param colormap: Either the name or the RGBA colors of the colormap to use.
:type colormap: Either str or numpy.ndarray with shape=(N, 4)
and dtype=numpy.uint8.
:param str norm: The normalization to use. Either 'linear' (the default)
or 'log' for log10 normalization.
:param bounds: The start and end value used to apply the colormap
or None (the default) to use auto-scale.
As is, start value must be <= end value.
:type bounds: tuple of two floats (startValue, endValue) or None.
:returns: The RGBA pixmap and the used start and end value.
:rtype: (numpy.ndarray with dtype=numpy.uint8, (float, float))
"""
if not isinstance(colormap, np.ndarray):
try:
colormap = COLORMAPS[colormap]
except KeyError:
raise RuntimeError("Invalid colormap: %s" % colormap)
isLog10 = norm.startswith('log')
if bounds is None:
start, end = None, None
else:
start, end = bounds
return ctools.dataToRGBAColormap(data, colormap, start, end, isLog10, None)
# demo ########################################################################
if __name__ == "__main__":
data = np.arange(1024 * 1024.)
data.shape = 1024, -1
for colormap in COLORMAPS:
pixmap, _ = applyColormap(data, colormap)
filename = 'demoColormap_%s.ppm' % colormap
print('Write generated RGB image to: %s' % filename)
with open(filename, 'w') as f:
f.write('P6\n%d %d\n255\n' % (pixmap.shape[1], pixmap.shape[0]))
f.write(pixmap[:, :, 0:3].tobytes())
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