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

   1 /*
   2  * Pixastic Lib - Edge detection 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.edges = {
   8         process : function(params) {
   9
  10                 var mono = !!(params.options.mono);
  11
  12                 var strength = 1.0;
  13
  14                 //if (typeof params.options.strength != "undefined")
  15                 //      strength = parseFloat(params.options.strength)||0;
  16
  17                 var invert = !!(params.options.invert);
  18
  19                 if (Pixastic.Client.hasCanvasImageData()) {
  20                         var data = Pixastic.prepareData(params);
  21                         var dataCopy = Pixastic.prepareData(params, true)
  22
  23                         var c = -strength/8;
  24                         var kernel = [
  25                                 [c,     c,      c],
  26                                 [c,     1,      c],
  27                                 [c,     c,      c]
  28                         ];
  29
  30                         weight = 1/c;
  31
  32                         var rect = params.options.rect;
  33                         var w = rect.width;
  34                         var h = rect.height;
  35
  36                         var w4 = w*4;
  37                         var y = h;
  38                         do {
  39                                 var offsetY = (y-1)*w4;
  40
  41                                 var nextY = (y == h) ? y - 1 : y;
  42                                 var prevY = (y == 1) ? 0 : y-2;
  43
  44                                 var offsetYPrev = prevY*w*4;
  45                                 var offsetYNext = nextY*w*4;
  46
  47                                 var x = w;
  48                                 do {
  49                                         var offset = offsetY + (x*4-4);
  50
  51                                         var offsetPrev = offsetYPrev + ((x == 1) ? 0 : x-2) * 4;
  52                                         var offsetNext = offsetYNext + ((x == w) ? x-1 : x) * 4;
  53
  54                                         var r = ((dataCopy[offsetPrev-4]
  55                                                 + dataCopy[offsetPrev]
  56                                                 + dataCopy[offsetPrev+4]
  57                                                 + dataCopy[offset-4]
  58                                                 + dataCopy[offset+4]
  59                                                 + dataCopy[offsetNext-4]
  60                                                 + dataCopy[offsetNext]
  61                                                 + dataCopy[offsetNext+4]) * c
  62                                                 + dataCopy[offset]
  63                                                 )
  64                                                 * weight;
  65
  66                                         var g = ((dataCopy[offsetPrev-3]
  67                                                 + dataCopy[offsetPrev+1]
  68                                                 + dataCopy[offsetPrev+5]
  69                                                 + dataCopy[offset-3]
  70                                                 + dataCopy[offset+5]
  71                                                 + dataCopy[offsetNext-3]
  72                                                 + dataCopy[offsetNext+1]
  73                                                 + dataCopy[offsetNext+5]) * c
  74                                                 + dataCopy[offset+1])
  75                                                 * weight;
  76
  77                                         var b = ((dataCopy[offsetPrev-2]
  78                                                 + dataCopy[offsetPrev+2]
  79                                                 + dataCopy[offsetPrev+6]
  80                                                 + dataCopy[offset-2]
  81                                                 + dataCopy[offset+6]
  82                                                 + dataCopy[offsetNext-2]
  83                                                 + dataCopy[offsetNext+2]
  84                                                 + dataCopy[offsetNext+6]) * c
  85                                                 + dataCopy[offset+2])
  86                                                 * weight;
  87
  88                                         if (mono) {
  89                                                 var brightness = (r*0.3 + g*0.59 + b*0.11)||0;
  90                                                 if (invert) brightness = 255 - brightness;
  91                                                 if (brightness < 0 ) brightness = 0;
  92                                                 if (brightness > 255 ) brightness = 255;
  93                                                 r = g = b = brightness;
  94                                         } else {
  95                                                 if (invert) {
  96                                                         r = 255 - r;
  97                                                         g = 255 - g;
  98                                                         b = 255 - b;
  99                                                 }
 100                                                 if (r < 0 ) r = 0;
 101                                                 if (g < 0 ) g = 0;
 102                                                 if (b < 0 ) b = 0;
 103                                                 if (r > 255 ) r = 255;
 104                                                 if (g > 255 ) g = 255;
 105                                                 if (b > 255 ) b = 255;
 106                                         }
 107
 108                                         data[offset] = r;
 109                                         data[offset+1] = g;
 110                                         data[offset+2] = b;
 111
 112                                 } while (--x);
 113                         } while (--y);
 114
 115                         return true;
 116                 }
 117         },
 118         checkSupport : function() {
 119                 return Pixastic.Client.hasCanvasImageData();
 120         }
 121 }