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#!/usr/bin/env python3
# Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from curve import *
def load_icc(pathname):
'''
Load ICC profile from a file
@param pathname The ICC profile file
@return Function to invoke, parameterless, to apply the ICC profile to the colour curves
'''
MLUT_TAG = 0x6d4c5554
VCGT_TAG = 0x76636774
def fcurve(R_curve, G_curve, B_curve):
for curve, icc in curves(R_curve, G_curve, B_curve):
for i in range(i_size):
y = int(curve[i] * (len(icc) - 1) + 0.5)
y = min(max(0, y), len(icc) - 1)
curve[i] = icc[y]
int_ = lambda bs : sum([bs[len(bs) - 1 - i] << (8 * i) for i in range(len(bs))])
def read(n):
if len(content) < n:
raise Except("Premature end of file: %s" % pathname)
rc, content[:] = content[:n], content[n:]
return rc
content = None
with open(pathname, 'rb') as file:
content = file.read()
content = list(content)
read(128)
R_curve, G_curve, B_curve = [], [], []
n_tags, ptr = int_(read(4)), 128 + 4
for i_tag in range(n_tags):
tag_name = int_(read(4))
tag_offset = int_(read(4))
tag_size = int_(read(4))
ptr += 3 * 4
if tag_name == MLUT_TAG:
read(tag_offset - ptr)
for i in range(256): R_curve.append(int_(read(2)) / 65535)
for i in range(256): G_curve.append(int_(read(2)) / 65535)
for i in range(256): B_curve.append(int_(read(2)) / 65535)
return lambda : fcurve(R_curve, G_curve, B_curve)
elif tag_name == VCGT_TAG:
read(tag_offset - ptr)
tag_name = int_(read(4))
if not tag_name == VCGT_TAG:
break
read(4)
gamma_type = int_(read(4))
if gamma_type == 0:
n_channels = int_(read(2))
n_entries = int_(read(2))
entry_size = int_(read(2))
if tag_size == 1584:
n_channels, n_entries, entry_size = 3, 256, 2
if not n_channels == 3: # assuming sRGB
break
int__ = lambda m : int_(read(m)) / ((256 ** m) - 1)
for i in range(n_entries): R_curve.append(int__(entry_size))
for i in range(n_entries): G_curve.append(int__(entry_size))
for i in range(n_entries): B_curve.append(int__(entry_size))
return lambda : fcurve(R_curve, G_curve, B_curve)
elif gamma_type == 1:
r_gamma = int_(read(4)) / 65535
r_min = int_(read(4)) / 65535
r_max = int_(read(4)) / 65535
g_gamma = int_(read(4)) / 65535
g_min = int_(read(4)) / 65535
g_max = int_(read(4)) / 65535
b_gamma = int_(read(4)) / 65535
b_min = int_(read(4)) / 65535
b_max = int_(read(4)) / 65535
def f():
gamma(r_gamma, g_gamma, b_gamma)
rgb_limits(r_min, r_max, g_min, g_max, b_min, b_max)
return f
break
raise Exception("Unsupported ICC profile file")
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