js2/mwEmbed/libClipEdit/pixastic-lib/actions/noise.js

   1 /*
   2  * Pixastic Lib - Noise filter - v0.1.0
   3  * Copyright (c) 2008 Jacob Seidelin, jseidelin@nihilogic.dk, http://blog.nihilogic.dk/
   4  * MIT License [http://www.opensource.org/licenses/mit-license.php]
   5  */
   6
   7 Pixastic.Actions.noise = {
   8
   9         process : function(params) {
  10                 var amount = 0;
  11                 var strength = 0;
  12                 var mono = false;
  13
  14                 if (typeof params.options.amount != "undefined")
  15                         amount = parseFloat(params.options.amount)||0;
  16                 if (typeof params.options.strength != "undefined")
  17                         strength = parseFloat(params.options.strength)||0;
  18                 if (typeof params.options.mono != "undefined")
  19                         mono = !!(params.options.mono);
  20
  21                 amount = Math.max(0,Math.min(1,amount));
  22                 strength = Math.max(0,Math.min(1,strength));
  23
  24                 var noise = 128 * strength;
  25                 var noise2 = noise / 2;
  26
  27                 if (Pixastic.Client.hasCanvasImageData()) {
  28                         var data = Pixastic.prepareData(params);
  29                         var rect = params.options.rect;
  30                         var w = rect.width;
  31                         var h = rect.height;
  32                         var w4 = w*4;
  33                         var y = h;
  34                         var random = Math.random;
  35
  36                         do {
  37                                 var offsetY = (y-1)*w4;
  38                                 var x = w;
  39                                 do {
  40                                         var offset = offsetY + (x-1)*4;
  41                                         if (random() < amount) {
  42                                                 if (mono) {
  43                                                         var pixelNoise = - noise2 + random() * noise;
  44                                                         var r = data[offset] + pixelNoise;
  45                                                         var g = data[offset+1] + pixelNoise;
  46                                                         var b = data[offset+2] + pixelNoise;
  47                                                 } else {
  48                                                         var r = data[offset] - noise2 + (random() * noise);
  49                                                         var g = data[offset+1] - noise2 + (random() * noise);
  50                                                         var b = data[offset+2] - noise2 + (random() * noise);
  51                                                 }
  52
  53                                                 if (r < 0 ) r = 0;
  54                                                 if (g < 0 ) g = 0;
  55                                                 if (b < 0 ) b = 0;
  56                                                 if (r > 255 ) r = 255;
  57                                                 if (g > 255 ) g = 255;
  58                                                 if (b > 255 ) b = 255;
  59
  60                                                 data[offset] = r;
  61                                                 data[offset+1] = g;
  62                                                 data[offset+2] = b;
  63                                         }
  64                                 } while (--x);
  65                         } while (--y);
  66                         return true;
  67                 }
  68         },
  69         checkSupport : function() {
  70                 return Pixastic.Client.hasCanvasImageData();
  71         }
  72 }
  73