ꦫꦣꦺꦤ꧀ꦄꦤ꧀ꦠꦱꦺꦤ

PATH: usr / lib64 / python3.6

"""Conversion functions between RGB and other color systems.

This modules provides two functions for each color system ABC:

rgb_to_abc(r, g, b) --> a, b, c
  abc_to_rgb(a, b, c) --> r, g, b

All inputs and outputs are triples of floats in the range [0.0...1.0]
(with the exception of I and Q, which covers a slightly larger range).
Inputs outside the valid range may cause exceptions or invalid outputs.

Supported color systems:
RGB: Red, Green, Blue components
YIQ: Luminance, Chrominance (used by composite video signals)
HLS: Hue, Luminance, Saturation
HSV: Hue, Saturation, Value
"""

# References:
# http://en.wikipedia.org/wiki/YIQ
# http://en.wikipedia.org/wiki/HLS_color_space
# http://en.wikipedia.org/wiki/HSV_color_space

__all__ = ["rgb_to_yiq","yiq_to_rgb","rgb_to_hls","hls_to_rgb",
           "rgb_to_hsv","hsv_to_rgb"]

# Some floating point constants

ONE_THIRD = 1.0/3.0
ONE_SIXTH = 1.0/6.0
TWO_THIRD = 2.0/3.0

# YIQ: used by composite video signals (linear combinations of RGB)
# Y: perceived grey level (0.0 == black, 1.0 == white)
# I, Q: color components
#
# There are a great many versions of the constants used in these formulae.
# The ones in this library uses constants from the FCC version of NTSC.

def rgb_to_yiq(r, g, b):
    y = 0.30*r + 0.59*g + 0.11*b
    i = 0.74*(r-y) - 0.27*(b-y)
    q = 0.48*(r-y) + 0.41*(b-y)
    return (y, i, q)

def yiq_to_rgb(y, i, q):
    # r = y + (0.27*q + 0.41*i) / (0.74*0.41 + 0.27*0.48)
    # b = y + (0.74*q - 0.48*i) / (0.74*0.41 + 0.27*0.48)
    # g = y - (0.30*(r-y) + 0.11*(b-y)) / 0.59

r = y + 0.9468822170900693*i + 0.6235565819861433*q
    g = y - 0.27478764629897834*i - 0.6356910791873801*q
    b = y - 1.1085450346420322*i + 1.7090069284064666*q

if r < 0.0:
        r = 0.0
    if g < 0.0:
        g = 0.0
    if b < 0.0:
        b = 0.0
    if r > 1.0:
        r = 1.0
    if g > 1.0:
        g = 1.0
    if b > 1.0:
        b = 1.0
    return (r, g, b)

# HLS: Hue, Luminance, Saturation
# H: position in the spectrum
# L: color lightness
# S: color saturation

def rgb_to_hls(r, g, b):
    maxc = max(r, g, b)
    minc = min(r, g, b)
    # XXX Can optimize (maxc+minc) and (maxc-minc)
    l = (minc+maxc)/2.0
    if minc == maxc:
        return 0.0, l, 0.0
    if l <= 0.5:
        s = (maxc-minc) / (maxc+minc)
    else:
        s = (maxc-minc) / (2.0-maxc-minc)
    rc = (maxc-r) / (maxc-minc)
    gc = (maxc-g) / (maxc-minc)
    bc = (maxc-b) / (maxc-minc)
    if r == maxc:
        h = bc-gc
    elif g == maxc:
        h = 2.0+rc-bc
    else:
        h = 4.0+gc-rc
    h = (h/6.0) % 1.0
    return h, l, s

def hls_to_rgb(h, l, s):
    if s == 0.0:
        return l, l, l
    if l <= 0.5:
        m2 = l * (1.0+s)
    else:
        m2 = l+s-(l*s)
    m1 = 2.0*l - m2
    return (_v(m1, m2, h+ONE_THIRD), _v(m1, m2, h), _v(m1, m2, h-ONE_THIRD))

def _v(m1, m2, hue):
    hue = hue % 1.0
    if hue < ONE_SIXTH:
        return m1 + (m2-m1)*hue*6.0
    if hue < 0.5:
        return m2
    if hue < TWO_THIRD:
        return m1 + (m2-m1)*(TWO_THIRD-hue)*6.0
    return m1

# HSV: Hue, Saturation, Value
# H: position in the spectrum
# S: color saturation ("purity")
# V: color brightness

def rgb_to_hsv(r, g, b):
    maxc = max(r, g, b)
    minc = min(r, g, b)
    v = maxc
    if minc == maxc:
        return 0.0, 0.0, v
    s = (maxc-minc) / maxc
    rc = (maxc-r) / (maxc-minc)
    gc = (maxc-g) / (maxc-minc)
    bc = (maxc-b) / (maxc-minc)
    if r == maxc:
        h = bc-gc
    elif g == maxc:
        h = 2.0+rc-bc
    else:
        h = 4.0+gc-rc
    h = (h/6.0) % 1.0
    return h, s, v

def hsv_to_rgb(h, s, v):
    if s == 0.0:
        return v, v, v
    i = int(h*6.0) # XXX assume int() truncates!
    f = (h*6.0) - i
    p = v*(1.0 - s)
    q = v*(1.0 - s*f)
    t = v*(1.0 - s*(1.0-f))
    i = i%6
    if i == 0:
        return v, t, p
    if i == 1:
        return q, v, p
    if i == 2:
        return p, v, t
    if i == 3:
        return p, q, v
    if i == 4:
        return t, p, v
    if i == 5:
        return v, p, q
    # Cannot get here

[+] ..
[-] __phello__.foo.py [edit]
[-] zipfile.py [edit]
[-] _dummy_thread.py [edit]
[-] signal.py [edit]
[-] tabnanny.py [edit]
[-] cmd.py [edit]
[-] cProfile.py [edit]
[-] tempfile.py [edit]
[-] argparse.py [edit]
[-] platform.py [edit]
[-] binhex.py [edit]
[-] antigravity.py [edit]
[+] curses
[-] _compat_pickle.py [edit]
[-] statistics.py [edit]
[-] inspect.py [edit]
[-] ipaddress.py [edit]
[-] sunau.py [edit]
[-] imghdr.py [edit]
[-] random.py [edit]
[-] macpath.py [edit]
[-] hmac.py [edit]
[-] base64.py [edit]
[-] cgitb.py [edit]
[-] stringprep.py [edit]
[-] ast.py [edit]
[-] textwrap.py [edit]
[-] enum.py [edit]
[-] _compression.py [edit]
[-] dis.py [edit]
[+] venv
[-] chunk.py [edit]
[-] this.py [edit]
[-] py_compile.py [edit]
[-] fnmatch.py [edit]
[+] xml
[-] opcode.py [edit]
[+] site-packages
[-] sre_compile.py [edit]
[-] _pyio.py [edit]
[-] pty.py [edit]
[-] datetime.py [edit]
[-] macurl2path.py [edit]
[+] lib2to3
[+] wsgiref
[-] heapq.py [edit]
[-] keyword.py [edit]
[-] codecs.py [edit]
[+] ensurepip
[-] pickletools.py [edit]
[-] compileall.py [edit]
[-] nturl2path.py [edit]
[-] warnings.py [edit]
[-] shutil.py [edit]
[-] socket.py [edit]
[-] pdb.py [edit]
[-] zipapp.py [edit]
[-] formatter.py [edit]
[-] _sitebuiltins.py [edit]
[-] _markupbase.py [edit]
[-] types.py [edit]
[-] runpy.py [edit]
[-] uu.py [edit]
[-] typing.py [edit]
[-] pathlib.py [edit]
[-] _threading_local.py [edit]
[-] mailcap.py [edit]
[-] bisect.py [edit]
[-] linecache.py [edit]
[-] colorsys.py [edit]
[-] glob.py [edit]
[-] sndhdr.py [edit]
[-] ssl.py [edit]
[-] _strptime.py [edit]
[-] _sysconfigdata_m_linux_x86_64-linux-gnu.py [edit]
[-] imp.py [edit]
[-] contextlib.py [edit]
[-] copyreg.py [edit]
[-] filecmp.py [edit]
[+] logging
[-] operator.py [edit]
[-] token.py [edit]
[-] gzip.py [edit]
[-] string.py [edit]
[-] genericpath.py [edit]
[-] _osx_support.py [edit]
[-] stat.py [edit]
[-] lzma.py [edit]
[-] __future__.py [edit]
[+] distutils
[-] dummy_threading.py [edit]
[+] asyncio
[-] webbrowser.py [edit]
[-] symtable.py [edit]
[+] lib-dynload
[-] getopt.py [edit]
[-] wave.py [edit]
[-] codeop.py [edit]
[-] _sysconfigdata_dm_linux_x86_64-linux-gnu.py [edit]
[-] abc.py [edit]
[+] config-3.6m-x86_64-linux-gnu
[+] pydoc_data
[-] telnetlib.py [edit]
[+] unittest
[-] fileinput.py [edit]
[-] ftplib.py [edit]
[+] ctypes
[-] _bootlocale.py [edit]
[-] pipes.py [edit]
[-] aifc.py [edit]
[-] pprint.py [edit]
[-] queue.py [edit]
[-] difflib.py [edit]
[+] __pycache__
[-] uuid.py [edit]
[-] reprlib.py [edit]
[-] threading.py [edit]
[+] http
[-] sre_parse.py [edit]
[-] subprocess.py [edit]
[+] importlib
[-] selectors.py [edit]
[-] getpass.py [edit]
[-] trace.py [edit]
[-] struct.py [edit]
[-] tracemalloc.py [edit]
[-] plistlib.py [edit]
[-] asynchat.py [edit]
[-] fractions.py [edit]
[-] shlex.py [edit]
[-] bdb.py [edit]
[-] locale.py [edit]
[-] calendar.py [edit]
[-] poplib.py [edit]
[-] posixpath.py [edit]
[-] imaplib.py [edit]
[+] concurrent
[-] pickle.py [edit]
[-] timeit.py [edit]
[+] json
[-] traceback.py [edit]
[+] multiprocessing
[-] shelve.py [edit]
[-] csv.py [edit]
[-] tarfile.py [edit]
[-] numbers.py [edit]
[-] optparse.py [edit]
[-] cgi.py [edit]
[-] pstats.py [edit]
[-] crypt.py [edit]
[+] collections
[-] site.py [edit]
[-] pkgutil.py [edit]
[-] re.py [edit]
[-] pyclbr.py [edit]
[-] socketserver.py [edit]
[-] _pydecimal.py [edit]
[-] pydoc.py [edit]
[-] sre_constants.py [edit]
[-] xdrlib.py [edit]
[-] nntplib.py [edit]
[-] mimetypes.py [edit]
[+] email
[-] quopri.py [edit]
[-] doctest.py [edit]
[-] profile.py [edit]
[-] sched.py [edit]
[-] hashlib.py [edit]
[+] urllib
[-] secrets.py [edit]
[-] functools.py [edit]
[-] smtplib.py [edit]
[-] copy.py [edit]
[+] dbm
[-] tty.py [edit]
[-] os.py [edit]
[-] _collections_abc.py [edit]
[-] configparser.py [edit]
[-] _weakrefset.py [edit]
[-] netrc.py [edit]
[-] code.py [edit]
[-] asyncore.py [edit]
[-] tokenize.py [edit]
[+] encodings
[-] io.py [edit]
[-] smtpd.py [edit]
[-] sysconfig.py [edit]
[-] decimal.py [edit]
[+] sqlite3
[-] rlcompleter.py [edit]
[-] ntpath.py [edit]
[+] test
[-] weakref.py [edit]
[-] symbol.py [edit]
[-] modulefinder.py [edit]
[+] xmlrpc
[-] bz2.py [edit]
[-] gettext.py [edit]
[-] mailbox.py [edit]
[+] html