Created
March 30, 2012 05:18
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IRIDAS .look to .csp LUT
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"""From the seemingly undocumented IRIDAS .look format to .csp | |
""" | |
import re | |
import os | |
import sys | |
import struct | |
import binascii | |
import xml.etree.ElementTree as ET | |
class LookParsingError(Exception): | |
pass | |
def warn(msg): | |
sys.stderr.write("%s\n" % msg) | |
def chunks(l, n): | |
""" Yield successive n-sized chunks from l. | |
""" | |
for i in xrange(0, len(l), n): | |
yield l[i:i+n] | |
class LookParser(object): | |
"""Slightly hacky parser for IRIDAS's .look LUT | |
""" | |
def __init__(self, source): | |
"""source is string containing .look file contents | |
""" | |
tree = ET.fromstring(source) | |
self.lut3d = self.parse_lut3d(tree) | |
def parse_lut3d(self, tree): | |
"""Parses the LUT section of the .look, which contains a | |
edge-size and binary 3D LUT. | |
Data is packed series of (float, float, float), and probably | |
something else (there is a suspicious 12 bytes left over..) | |
""" | |
# Data to return | |
lut3d = {} | |
# Get 3D LUT edge size from | |
# <LUT> | |
# <size>"8"</size> | |
lut = tree.find("LUT") | |
cube_edge_size = int(lut.find("size").text.replace("\"", "")) | |
lut3d['edgelen'] = cube_edge_size | |
# Clean up LUT data - remove whitespace, quotes etc | |
lutdata = lut.find("data").text | |
lutdata = re.sub("[^A-Z0-9]+", "", lutdata) | |
# Parse 3D LUT data | |
data_binary = binascii.unhexlify(lutdata) | |
# Little endian, 3 floats | |
format = "<fff" | |
samples = list(struct.unpack(format, chunk) for chunk in chunks(data_binary, struct.calcsize(format))) | |
if len(samples) != cube_edge_size ** 3: | |
raise LookParsingError("Cube size was not correct, was %s, expected %s (%s**3)" % ( | |
len(samples), | |
cube_edge_size**3, | |
cube_edge_size)) | |
lut3d['samples'] = samples | |
return lut3d | |
def csp_header_with_noop_prelut(): | |
lines = [] | |
lines.append("CSPLUTV100") | |
lines.append("3D") | |
lines.append("") | |
for x in range(3): | |
lines.append("2") | |
lines.append("0.0 1.0") | |
lines.append("0.0 1.0") | |
lines.append("") | |
return lines | |
def main(in_fname = None): | |
if in_fname is None: | |
in_fname = sys.argv[1] | |
f = open(in_fname) | |
contents = f.read() | |
p = LookParser(contents) | |
outcsp = csp_header_with_noop_prelut() | |
outcsp.append("%s %s %s" % ((p.lut3d['edgelen'],)*3)) | |
for s in p.lut3d['samples']: | |
outcsp.append("%.05f %.05f %.05f" % s) | |
out_fname = os.path.splitext(in_fname)[0] + ".csp" | |
df = open(out_fname, "w") | |
df.write("\n".join(outcsp)) | |
df.close() | |
if __name__ == "__main__": | |
main() |
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