使用Javascript将油画/素描效果应用于照片

Question

我想使用javascript从照片开始模拟人类绘画效果.

我一直在搜索几个进行图像处理的js库(主要是在画布上).但似乎没有人尝试过我正在寻找的东西.

我不认为用javascript实现这样的效果是不可能的.所以我想知道为什么我找不到任何已经完成的事情.

在本机方面,有几种替代photoshop可以实现这样的效果,如App Store中的几个应用程序所示:

• 油画展位免费
• 一笔
• Autopainter
• 艺术家的触摸
• Autographo

以下是可能结果的其他示例(来自Artist的Touch App):

Answer 1

好吧,所以我找到了这里使用的算法的一个很好的解释,并将其改编为JS和canvas.

现场演示

CodePen演示使用控件来搞乱效果

它的工作原理是平均中心像素周围的所有像素,然后将该平均值乘以所需的强度等级,然后将其除以255.然后增加与强度等级相关的r/g/b.然后检查像素邻居中最常见的强度等级,并为目标像素分配强度等级.

编辑对它进行了更多的工作并重写了很多,获得了一些非常巨大的性能提升,现在很好地适用于尺寸合适的图像.

var canvas = document.getElementById("canvas"),
    ctx = canvas.getContext("2d"),
    img = new Image();

img.addEventListener('load', function () {
    canvas.width = this.width;
    canvas.height = this.height;
    ctx.drawImage(this, 0, 0, canvas.width, canvas.height);
    oilPaintEffect(canvas, 4, 55);
});

img.crossOrigin = "Anonymous";
img.src = "https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpa1/v/t1.0-9/1379992_10202357787410559_1075078295_n.jpg?oh=5b001e9848796dd942f47a0b2f3df6af&oe=542F3FEF&__gda__=1412145968_4dbb7f75b385770ecc3f4b88105cb0f8";

function oilPaintEffect(canvas, radius, intensity) {
    var width = canvas.width,
        height = canvas.height,
        imgData = ctx.getImageData(0, 0, width, height),
        pixData = imgData.data,
        destCanvas = document.createElement("canvas"),
        dCtx = destCanvas.getContext("2d"),
        pixelIntensityCount = [];

    destCanvas.width = width;
    destCanvas.height = height;

    // for demo purposes, remove this to modify the original canvas
    document.body.appendChild(destCanvas);

    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);
}