Files
konva/src/filters/HSV.js

91 lines
2.7 KiB
JavaScript

(function () {
/**
* HSV Filter. Adjusts the hue, saturation and value
* @function
* @memberof Kinetic.Filters
* @param {Object} imageData
* @author ippo615
*/
Kinetic.Filters.HSV = function (imageData) {
var data = imageData.data,
nPixels = data.length,
v = Math.pow(2,this.value()),
s = Math.pow(2,this.saturation()),
h = Math.abs((this.hue()) + 360) % 360,
i;
// Basis for the technique used:
// http://beesbuzz.biz/code/hsv_color_transforms.php
// V is the value multiplier (1 for none, 2 for double, 0.5 for half)
// S is the saturation multiplier (1 for none, 2 for double, 0.5 for half)
// H is the hue shift in degrees (0 to 360)
// vsu = V*S*cos(H*PI/180);
// vsw = V*S*sin(H*PI/180);
//[ .299V+.701vsu+.168vsw .587V-.587vsu+.330vsw .114V-.114vsu-.497vsw ] [R]
//[ .299V-.299vsu-.328vsw .587V+.413vsu+.035vsw .114V-.114vsu+.292vsw ]*[G]
//[ .299V-.300vsu+1.25vsw .587V-.588vsu-1.05vsw .114V+.886vsu-.203vsw ] [B]
// Precompute the values in the matrix:
var vsu = v*s*Math.cos(h*Math.PI/180),
vsw = v*s*Math.sin(h*Math.PI/180);
// (result spot)(source spot)
var rr = 0.299*v+0.701*vsu+0.167*vsw,
rg = 0.587*v-0.587*vsu+0.330*vsw,
rb = 0.114*v-0.114*vsu-0.497*vsw;
var gr = 0.299*v-0.299*vsu-0.328*vsw,
gg = 0.587*v+0.413*vsu+0.035*vsw,
gb = 0.114*v-0.114*vsu+0.293*vsw;
var br = 0.299*v-0.300*vsu+1.250*vsw,
bg = 0.587*v-0.586*vsu-1.050*vsw,
bb = 0.114*v+0.886*vsu-0.200*vsw;
var r,g,b,a;
for (i = 0; i < nPixels; i += 4) {
r = data[i+0];
g = data[i+1];
b = data[i+2];
a = data[i+3];
data[i+0] = rr*r + rg*g + rb*b;
data[i+1] = gr*r + gg*g + gb*b;
data[i+2] = br*r + bg*g + bb*b;
data[i+3] = a; // alpha
}
};
Kinetic.Factory.addGetterSetter(Kinetic.Node, 'hue', 0, null, Kinetic.Factory.afterSetFilter);
/**
* get/set hsv hue in degrees
* @name hue
* @method
* @memberof Kinetic.Node.prototype
* @param {Number} hue value between 0 and 359
* @returns {Number}
*/
Kinetic.Factory.addGetterSetter(Kinetic.Node, 'saturation', 0, null, Kinetic.Factory.afterSetFilter);
/**
* get/set hsv saturation
* @name saturation
* @method
* @memberof Kinetic.Node.prototype
* @param {Number} saturation 0 is no change, -1.0 halves the saturation, 1.0 doubles, etc..
* @returns {Number}
*/
Kinetic.Factory.addGetterSetter(Kinetic.Node, 'value', 0, null, Kinetic.Factory.afterSetFilter);
/**
* get/set hsv value
* @name value
* @method
* @memberof Kinetic.Node.prototype
* @param {Number} value 0 is no change, -1.0 halves the value, 1.0 doubles, etc..
* @returns {Number}
*/
})();