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41 lines
1.2 KiB
JavaScript
41 lines
1.2 KiB
JavaScript
(function () {
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/**
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* Posterize Filter. Adjusts the channels so that there are no more
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* than n different values for that channel. This is also applied
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* to the alpha channel.
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* @function
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* @name Posterize
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* @author ippo615
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* @memberof Kinetic.Filters
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* @param {Object} imageData
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* @example
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* node.cache();
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* node.filters([Kinetic.Filters.Posterize]);
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* node.levels(0.8);
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*/
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Kinetic.Filters.Posterize = function (imageData) {
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// level must be between 1 and 255
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var levels = Math.round(this.levels() * 254) + 1,
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data = imageData.data,
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len = data.length,
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scale = (255 / levels),
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i;
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for (i = 0; i < len; i += 1) {
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data[i] = Math.floor(data[i] / scale) * scale;
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}
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};
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Kinetic.Factory.addGetterSetter(Kinetic.Node, 'levels', 0.5, null, Kinetic.Factory.afterSetFilter);
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/**
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* get/set levels. Must be a number between 0 and 1. Use with {@link Kinetic.Filters.Posterize} filter.
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* @name levels
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* @method
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* @memberof Kinetic.Node.prototype
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* @param {Number} level between 0 and 1
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* @returns {Number}
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*/
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})(); |