JavaScript

语言：

JaveScriptBabelCoffeeScript

确定

var canvas = document.getElementById("canvas"),

ctx = canvas.getContext("2d"),

img = new Image(),

effectEl = document.getElementById("effect"),

settings = {

radius: 4,

intensity: 25,

ApplyFilter: function() {

doOilPaintEffect();

}

}

img.addEventListener('load', function() {

// reduced the size by half for pen and performance.

canvas.width = (this.width / 2);

canvas.height = (this.height / 2);

ctx.drawImage(this, 0, 0, canvas.width, canvas.height);

doOilPaintEffect();

});

img.crossOrigin = "Anonymous";

img.src = "/uploads/161001/normal2.jpg";

var gui = new dat.GUI();

gui.add(settings, 'intensity');

gui.add(settings, 'radius');

gui.add(settings, 'ApplyFilter');

function doOilPaintEffect() {

oilPaintEffect(canvas, settings.radius, settings.intensity);

}

function oilPaintEffect(canvas, radius, intensity) {

var width = canvas.width,

height = canvas.height,

imgData = ctx.getImageData(0, 0, width, height),

pixData = imgData.data,

// change to createElement getting added element just for the demo

destCanvas = document.getElementById("dest-canvas"),

dCtx = destCanvas.getContext("2d"),

pixelIntensityCount = [];

destCanvas.width = width;

destCanvas.height = height;

var destImageData = dCtx.createImageData(width, height),

destPixData = destImageData.data,

intensityLUT = [],

rgbLUT = [];

for (var y = 0; y < height; y++) {

intensityLUT[y] = [];

rgbLUT[y] = [];

for (var x = 0; x < width; x++) {

var idx = (y * width + x) * 4,

r = pixData[idx],

g = pixData[idx + 1],

b = pixData[idx + 2],

avg = (r + g + b) / 3;

intensityLUT[y][x] = Math.round((avg * intensity) / 255);

rgbLUT[y][x] = {

r: r,

g: g,

b: b

};

}

}

for (y = 0; y < height; y++) {

for (x = 0; x < width; x++) {

pixelIntensityCount = [];

// Find intensities of nearest pixels within radius.

for (var yy = -radius; yy <= radius; yy++) {

for (var xx = -radius; xx <= radius; xx++) {

if (y + yy > 0 && y + yy < height && x + xx > 0 && x + xx < width) {

var intensityVal = intensityLUT[y + yy][x + xx];

if (!pixelIntensityCount[intensityVal]) {

pixelIntensityCount[intensityVal] = {

val: 1,

r: rgbLUT[y + yy][x + xx].r,

g: rgbLUT[y + yy][x + xx].g,

b: rgbLUT[y + yy][x + xx].b

}

} else {

pixelIntensityCount[intensityVal].val++;

pixelIntensityCount[intensityVal].r += rgbLUT[y + yy][x + xx].r;

pixelIntensityCount[intensityVal].g += rgbLUT[y + yy][x + xx].g;

pixelIntensityCount[intensityVal].b += rgbLUT[y + yy][x + xx].b;

}

}

}

}

pixelIntensityCount.sort(function(a, b) {

return b.val - a.val;

});

var curMax = pixelIntensityCount[0].val,

dIdx = (y * width + x) * 4;

destPixData[dIdx] = ~~(pixelIntensityCount[0].r / curMax);

destPixData[dIdx + 1] = ~~(pixelIntensityCount[0].g / curMax);

destPixData[dIdx + 2] = ~~(pixelIntensityCount[0].b / curMax);

destPixData[dIdx + 3] = 255;

}

}

// change this to ctx to instead put the data on the original canvas

dCtx.putImageData(destImageData, 0, 0);

}