javascript图片相似度算法实现 js实现直方图和向量算法

代码如下:function getHistogram(imageData) {    var arr = [];    for (var i = 0; i < 64; i++) {        arr[i] = 0;    }    var data = imageData.data;    var pow4 = Math.pow(4, 2);    for (var i = 0, len = data.length; i < len; i += 4) {        var red = (data[i] / 64) | 0;        var green = (data[i + 1]