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]
7 Pixastic
.Actions
.edges
= {
8 process : function(params
) {
10 var mono
= !!(params
.options
.mono
);
14 //if (typeof params.options.strength != "undefined")
15 // strength = parseFloat(params.options.strength)||0;
17 var invert
= !!(params
.options
.invert
);
19 if (Pixastic
.Client
.hasCanvasImageData()) {
20 var data
= Pixastic
.prepareData(params
);
21 var dataCopy
= Pixastic
.prepareData(params
, true)
32 var rect
= params
.options
.rect
;
39 var offsetY
= (y
-1)*w4
;
41 var nextY
= (y
== h
) ? y
- 1 : y
;
42 var prevY
= (y
== 1) ? 0 : y
-2;
44 var offsetYPrev
= prevY
*w
*4;
45 var offsetYNext
= nextY
*w
*4;
49 var offset
= offsetY
+ (x
*4-4);
51 var offsetPrev
= offsetYPrev
+ ((x
== 1) ? 0 : x
-2) * 4;
52 var offsetNext
= offsetYNext
+ ((x
== w
) ? x
-1 : x
) * 4;
54 var r
= ((dataCopy
[offsetPrev
-4]
55 + dataCopy
[offsetPrev
]
56 + dataCopy
[offsetPrev
+4]
59 + dataCopy
[offsetNext
-4]
60 + dataCopy
[offsetNext
]
61 + dataCopy
[offsetNext
+4]) * c
66 var g
= ((dataCopy
[offsetPrev
-3]
67 + dataCopy
[offsetPrev
+1]
68 + dataCopy
[offsetPrev
+5]
71 + dataCopy
[offsetNext
-3]
72 + dataCopy
[offsetNext
+1]
73 + dataCopy
[offsetNext
+5]) * c
77 var b
= ((dataCopy
[offsetPrev
-2]
78 + dataCopy
[offsetPrev
+2]
79 + dataCopy
[offsetPrev
+6]
82 + dataCopy
[offsetNext
-2]
83 + dataCopy
[offsetNext
+2]
84 + dataCopy
[offsetNext
+6]) * c
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
;
103 if (r
> 255 ) r
= 255;
104 if (g
> 255 ) g
= 255;
105 if (b
> 255 ) b
= 255;
118 checkSupport : function() {
119 return Pixastic
.Client
.hasCanvasImageData();