diff options
| -rwxr-xr-x | Demo/sgi/video/colorsys.py | 124 |
1 files changed, 100 insertions, 24 deletions
diff --git a/Demo/sgi/video/colorsys.py b/Demo/sgi/video/colorsys.py index b4e4b14..6735b35 100755 --- a/Demo/sgi/video/colorsys.py +++ b/Demo/sgi/video/colorsys.py @@ -1,30 +1,106 @@ -# Conversions between RGB and YIQ color spaces. # -# R, G, B are amounts of Red, Green and Blue; -# Y, I, Q are intensity (Y) and two difference signals (I, Q). - +# Module color - do color conversions +# -# Convert a (R, G, B) triple to (Y, I, Q). -# Scale is arbitrary (output uses the same scale as input). +ONE_THIRD=1.0/3.0 +ONE_SIXTH=1.0/6.0 +TWO_THIRD=2.0/3.0 -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 rgb_to_yiq(r,g,b): + y = 0.3*r + 0.59*g + 0.11*b + i = 0.6*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) +def _v(m1,m2,hue): + if hue >= 1.0: hue = hue - 1.0 + if hue < 0.0: 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 -# Convert a (Y, I, Q) triple to (R, G, B). -# Input and output values are in the interval [0.0 ... 1.0]. +def rgb_to_hls(r,g,b): + maxc = max(r,g,b) + minc = min(r,g,b) + 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-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 + if h < 0.0: + h = h + 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 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 +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 + if h < 0.0: + h = h + 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) + f = (h*6.0)-i + p = v*(1.0-s) + q = v*(1.0-s*f) + t = v*(1.0-s*(1.0-f)) + if i in (0,6): 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 + print i, h, f + print h, s, v + raise 'Bad color' |