图像处理滤镜算法和js代码实现全资料，总有你想要的

灰度滤镜

将RGB设置为与颜色相同的值，使图片变白。一般处理方法为： 1.取三种颜色的平均值 2.取三种颜色的最大（最小）值 3.加权平均：0.3R + 0.59G + 0.11*B

for(var i = 0; i < data.length; i+=4) {
     var grey = (data[i] + data[i+1] + data[i+2]) / 3;
     data[i] = data[i+1] = data[i+2] = grey;
}

复制代码

黑色和白色滤镜

顾名思义，图像颜色只有黑白。可以计算rgb的平均arg，arg>=100，r=g=b=255，否则0

for(var i = 0; i < data.length; i += 4) {
     var avg = (data[i] + data[i+1] + data[i+2]) / 3;
     data[i] = data[i+1] = data[i+2] = avg >= 100 ? 255 : 0;
}
复制代码

去色滤镜

RGB三种颜色取三种颜色的平均值。

for(var i = 0; i < data.length; i++) {
   var avg = Math.floor((Math.min(data[i], data[i+1], data[i+2]) + Math.max(data[i], data[i+1], data[i+2])) / 2 );
   data[i] = data[i+1] = data[i+2] = avg;
}
复制代码

单色滤镜

只保留一种颜色并将其设置为0

for(var i = 0; i < canvas.height * canvas.width; i++) {
    data[i*4 + 2] = 0;
    data[i*4 + 1] = 0;
}
复制代码

高斯模糊滤镜

高斯模糊的原理是让每个像素周围的像素基于正态分布。 ，将每个权重（每个权重之和为1）与对应的颜色值相乘，得到的和就是中心像素的新颜色值。关于高斯模糊公式的了解：

function gaussBlur(imgData, radius, sigma) {
    var pixes = imgData.data,
        height = imgData.height,
        width = imgData.width,
        radius = radius || 5;
        sigma = sigma || radius / 3;
    
    var gaussEdge = radius * 2 + 1;

    var gaussMatrix = [],
        gaussSum = 0,
        a = 1 / (2 * sigma * sigma * Math.PI),
        b = -a * Math.PI;
    
    for(var i = -radius; i <= radius; i++) {
        for(var j = -radius; j <= radius; j++) {
            var gxy = a * Math.exp((i * i + j * j) * b);
            gaussMatrix.push(gxy);
            gaussSum += gxy;
        }
    }
    var gaussNum = (radius + 1) * (radius + 1);
    for(var i = 0; i < gaussNum; i++) {
        gaussMatrix[i] /= gaussSum;
    }

    for(var x = 0; x < width; x++) {
        for(var y = 0; y < height; y++) {
            var r = g = b = 0;
            for(var i = -radius; i<=radius; i++) {
                var m = handleEdge(i, x, width);
                for(var j = -radius; j <= radius; j++) {
                    var mm = handleEdge(j, y, height);
                    var currentPixId = (mm * width + m) * 4;
                    var jj = j + radius;
                    var ii = i + radius;
                    r += pixes[currentPixId] * gaussMatrix[jj * gaussEdge + ii];
                    g += pixes[currentPixId + 1] * gaussMatrix[jj * gaussEdge + ii];
                    b += pixes[currentPixId + 2] * gaussMatrix[jj * gaussEdge + ii];
                }
            }
            var pixId = (y * width + x) * 4;

            pixes[pixId] = ~~r;
            pixes[pixId + 1] = ~~g;
            pixes[pixId + 2] = ~~b;
        }
    }
    imgData.data = pixes;
    return imgData;
}

function handleEdge(i, x, w) {
    var m = x + i;
    if(m < 0) {
        m = -m;
    } else if(m >= w) {
        m = w + i -x;
    }
    return m;
}
复制代码

怀旧滤镜

怀旧滤镜

for(var i = 0; i < imgData.height * imgData.width; i++) {
    var r = imgData.data[i*4],
        g = imgData.data[i*4+1],
        b = imgData.data[i*4+2];

    var newR = (0.393 * r + 0.769 * g + 0.189 * b);
    var newG = (0.349 * r + 0.686 * g + 0.168 * b);
    var newB = (0.272 * r + 0.534 * g + 0.131 * b);
    var rgbArr = [newR, newG, newB].map((e) => {
        return e < 0 ? 0 : e > 255 ? 255 : e;
    });
    [imgData.data[i*4], imgData.data[i*4+1], imgData.data[i*4+2]] = rgbArr;
}
复制代码

铸造滤镜

公式：r = r128/(g+b) g = g 128/ (r+b+1)； b = b*128/(g+r +1);

for(var i = 0; i < imgData.height * imgData.width; i++) {
    var r = imgData.data[i*4],
        g = imgData.data[i*4+1],
        b = imgData.data[i*4+2];

    var newR = r * 128 / (g + b + 1);
    var newG = g * 128 / (r + b + 1);
    var newB = b * 128 / (g + r + 1);
    var rgbArr = [newR, newG, newB].map((e) => {
        return e < 0 ? 0 : e > 255 ? 255 : e;
    });
    [imgData.data[i*4], imgData.data[i*4+1], imgData.data[i*4+2]] = rgbArr;
}
复制代码

冷滤

公式：r = (r-g-b)*3/2; g = (g-r-b)*3/2; b = (b-g-r)*3/2;

for(var i = 0; i < imgData.height * imgData.width; i++) {
    var r = imgData.data[i*4],
        g = imgData.data[i*4+1],
        b = imgData.data[i*4+2];

    var newR = (r - g -b) * 3 /2;
    var newG = (g - r -b) * 3 /2;
    var newB = (b - g -r) * 3 /2;
    var rgbArr = [newR, newG, newB].map((e) => {
        return e < 0 ? 0 : e > 255 ? 255 : e;
    });
    [imgData.data[i*4], imgData.data[i*4+1], imgData.data[i*4+2]] = rgbArr;
}
复制代码

漫画滤镜

公式：R = |g – b + g + r| * r / 256

G = |b – g + b + r| * r / 256;

B = |b – g + b + r| + g * 0.769 + b * 0.189； g = r * 0.349 + g * 0.686 + b * 0.168； b = r * 0.272 + g * 0.534 + b * 0.131;

for (var i = 0; i < imgData.height * imgData.width; i++) {
    var r = imgData.data[i * 4],
        g = imgData.data[i * 4 + 1],
        b = imgData.data[i * 4 + 2];

    var newR = r * 0.393 + g * 0.769 + b * 0.189;
    var newG = r * 0.349 + g * 0.686 + b * 0.168;
    var newB =  r * 0.272 + g * 0.534 + b * 0.131;
    var rgbArr = [newR, newG, newB];
    [imgData.data[i * 4], imgData.data[i * 4 + 1], imgData.data[i * 4 + 2]] = rgbArr;
}
复制代码

作者：GreyWind
链接：https://codeqd.com/zb_users/upload/2023/09/%e4%bb%a3%e7%a0%81%e5%ae%9e%e7%8e%b0%20%e6%80%bb%e6%9c%89%e4%bd%a0%e8%a6%81%e7%9a%84%e9%82%a3%e4%b8%80%e6%ac%be%22%20decoding=%22async%22%20class=%22lazyload%20inited%20loaded%22%20%20alt=%22image.png" data-src="https://user-gold-cdn.xitu.io/2018/9/16/165e1782192d71ba?imageView2/0/w/1280/h/960/format/webp/ignore-error/1" height="20" data-width="808" data-height="233" />

。如需商业印刷，请联系作者以获得许可。非商业转载请注明来源。