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| 55 | <H1><A NAME="SECTION0016700000000000000000"> |
| 56 | 14.7 <tt class="module">colorsys</tt> -- |
| 57 | Conversions between color systems</A> |
| 58 | </H1> |
| 59 | |
| 60 | <P> |
| 61 | <A NAME="module-colorsys"></A> |
| 62 | |
| 63 | <P> |
| 64 | The <tt class="module">colorsys</tt> module defines bidirectional conversions of |
| 65 | color values between colors expressed in the RGB (Red Green Blue) |
| 66 | color space used in computer monitors and three other coordinate |
| 67 | systems: YIQ, HLS (Hue Lightness Saturation) and HSV (Hue Saturation |
| 68 | Value). Coordinates in all of these color spaces are floating point |
| 69 | values. In the YIQ space, the Y coordinate is between 0 and 1, but |
| 70 | the I and Q coordinates can be positive or negative. In all other |
| 71 | spaces, the coordinates are all between 0 and 1. |
| 72 | |
| 73 | <P> |
| 74 | More information about color spaces can be found at |
| 75 | <a class="url" href="http://www.poynton.com/ColorFAQ.html">http://www.poynton.com/ColorFAQ.html</a>. |
| 76 | |
| 77 | <P> |
| 78 | The <tt class="module">colorsys</tt> module defines the following functions: |
| 79 | |
| 80 | <P> |
| 81 | <dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline"> |
| 82 | <td><nobr><b><tt id='l2h-4749' xml:id='l2h-4749' class="function">rgb_to_yiq</tt></b>(</nobr></td> |
| 83 | <td><var>r, g, b</var>)</td></tr></table></dt> |
| 84 | <dd> |
| 85 | Convert the color from RGB coordinates to YIQ coordinates. |
| 86 | </dl> |
| 87 | |
| 88 | <P> |
| 89 | <dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline"> |
| 90 | <td><nobr><b><tt id='l2h-4750' xml:id='l2h-4750' class="function">yiq_to_rgb</tt></b>(</nobr></td> |
| 91 | <td><var>y, i, q</var>)</td></tr></table></dt> |
| 92 | <dd> |
| 93 | Convert the color from YIQ coordinates to RGB coordinates. |
| 94 | </dl> |
| 95 | |
| 96 | <P> |
| 97 | <dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline"> |
| 98 | <td><nobr><b><tt id='l2h-4751' xml:id='l2h-4751' class="function">rgb_to_hls</tt></b>(</nobr></td> |
| 99 | <td><var>r, g, b</var>)</td></tr></table></dt> |
| 100 | <dd> |
| 101 | Convert the color from RGB coordinates to HLS coordinates. |
| 102 | </dl> |
| 103 | |
| 104 | <P> |
| 105 | <dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline"> |
| 106 | <td><nobr><b><tt id='l2h-4752' xml:id='l2h-4752' class="function">hls_to_rgb</tt></b>(</nobr></td> |
| 107 | <td><var>h, l, s</var>)</td></tr></table></dt> |
| 108 | <dd> |
| 109 | Convert the color from HLS coordinates to RGB coordinates. |
| 110 | </dl> |
| 111 | |
| 112 | <P> |
| 113 | <dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline"> |
| 114 | <td><nobr><b><tt id='l2h-4753' xml:id='l2h-4753' class="function">rgb_to_hsv</tt></b>(</nobr></td> |
| 115 | <td><var>r, g, b</var>)</td></tr></table></dt> |
| 116 | <dd> |
| 117 | Convert the color from RGB coordinates to HSV coordinates. |
| 118 | </dl> |
| 119 | |
| 120 | <P> |
| 121 | <dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline"> |
| 122 | <td><nobr><b><tt id='l2h-4754' xml:id='l2h-4754' class="function">hsv_to_rgb</tt></b>(</nobr></td> |
| 123 | <td><var>h, s, v</var>)</td></tr></table></dt> |
| 124 | <dd> |
| 125 | Convert the color from HSV coordinates to RGB coordinates. |
| 126 | </dl> |
| 127 | |
| 128 | <P> |
| 129 | Example: |
| 130 | |
| 131 | <P> |
| 132 | <div class="verbatim"><pre> |
| 133 | >>> import colorsys |
| 134 | >>> colorsys.rgb_to_hsv(.3, .4, .2) |
| 135 | (0.25, 0.5, 0.4) |
| 136 | >>> colorsys.hsv_to_rgb(0.25, 0.5, 0.4) |
| 137 | (0.3, 0.4, 0.2) |
| 138 | </pre></div> |
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