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Commit Description:
merge with algo and add brython files that were missing
Commit Description:
merge with algo and add brython files that were missing
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lib/assets/Lib/colorsys.py
| 156 lines
| 3.8 KiB
| text/x-python
| PythonLexer
|
| r584 | """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 | ||||