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Diffstat (limited to 'AppPkg/Applications/Python/Python-2.7.2/Lib/colorsys.py')
| -rw-r--r-- | AppPkg/Applications/Python/Python-2.7.2/Lib/colorsys.py | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/AppPkg/Applications/Python/Python-2.7.2/Lib/colorsys.py b/AppPkg/Applications/Python/Python-2.7.2/Lib/colorsys.py new file mode 100644 index 0000000000..194fea790f --- /dev/null +++ b/AppPkg/Applications/Python/Python-2.7.2/Lib/colorsys.py @@ -0,0 +1,156 @@ +"""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
+
+def rgb_to_yiq(r, g, b):
+ y = 0.30*r + 0.59*g + 0.11*b
+ i = 0.60*r - 0.28*g - 0.32*b
+ q = 0.21*r - 0.52*g + 0.31*b
+ return (y, i, q)
+
+def yiq_to_rgb(y, i, q):
+ r = y + 0.948262*i + 0.624013*q
+ g = y - 0.276066*i - 0.639810*q
+ b = y - 1.105450*i + 1.729860*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
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