在这个小提琴上,这些功能完美地完成了这项工作,但我需要稍微调整一下这个结点。
有没有办法让这个功能做我需要的?
getImageBrightness(this.src,function(brightness) {
document.getElementsByTagName('pre')[0].innerHTML = "Brightness: "+brightness;
});
jsfiddle.net/s7Wx2 /
答案 0 :(得分:1)
在您的HTML中,我只在id
添加了img
我玩了一点纯粹的javascript getImageBrightness
......但不是那么多。
我使用" 127.5"作为黑暗与光明之间的中间线 我建议你评价一下......因为人眼不像脚本一样数学 ;)
这是脚本:
var thisImg;
function getImageBrightness(image,callback) {
var thisImgID = image.attr("id");
var img = document.createElement("img");
img.src = image.attr("src");
img.style.display = "none";
document.body.appendChild(img);
var colorSum = 0;
img.onload = function() {
// create canvas
var canvas = document.createElement("canvas");
canvas.width = this.width;
canvas.height = this.height;
var ctx = canvas.getContext("2d");
ctx.drawImage(this,0,0);
var imageData = ctx.getImageData(0,0,canvas.width,canvas.height);
var data = imageData.data;
var r,g,b,avg;
for(var x = 0, len = data.length; x < len; x+=4) {
r = data[x];
g = data[x+1];
b = data[x+2];
avg = Math.floor((r+g+b)/3);
colorSum += avg;
}
var brightness = Math.floor(colorSum / (this.width*this.height));
callback(thisImgID, brightness);
}
}
$("img").on("click", function(){
thisImg = $(this)
getImageBrightness( $(this),function( thisImgID, brightness ) {
document.getElementsByTagName('pre')[0].innerHTML = "Brightness: "+brightness+"<br><br>- Red border means class added -> dark,<br>- yellow border mean class added -> light";
if(brightness<127.5){
$("#"+thisImgID).addClass("dark");
}else{
$("#"+thisImgID).addClass("light");
}
});
});
CSS:
.dark{
border:3px solid red;
}
.light{
border:3px solid yellow;
}