我发布了一个问题,但我无法正确解释(setting font color by taking image average color)并且stackoverflow不允许我上传多个链接,所以我将尝试再次解释这个问题。请原谅我,如果我犯了任何错误,我是新来的,实际上我想要取出图像上特定区域的平均颜色。我看过很多计算整个图像平均颜色的例子。
我有两个文本框。 textbox1颜色将基于其背景颜色(云彩平均值)的平均值,而不是整个图像的平均值。同样,底部颜色的文本框2应该是其背景颜色平均值(高速公路颜色)的平均值。
答案 0 :(得分:1)
谢谢,我得到了答案。感谢@Cinn 帮助我解决这个问题。如果有人想查找图片中特定区域的平均颜色,请访问JsFiddle链接。
var average_color_background = function(image, title) {
var treat_properties = function(elmt_propertie) {
return parseInt(elmt_propertie.replace(/px/, ''));
}
var image_width = treat_properties(getComputedStyle(image, null).width),
image_height = treat_properties(getComputedStyle(image, null).height),
title_width = treat_properties(getComputedStyle(title, null).width),
title_height = treat_properties(getComputedStyle(title, null).height),
title_top = treat_properties(getComputedStyle(title, null).top),
title_left = treat_properties(getComputedStyle(title, null).left);
var c = document.createElement('canvas');
c.width = image_width;
c.height = image_height;
c.style.position = "absolute";
c.style.top = 0;
c.style.left = 0;
c.style.zIndex = 0; // invisible calculation
document.getElementsByTagName('body')[0].appendChild(c);
var ctx = c.getContext("2d");
var image_bis = new Image();
image_bis.crossOrigin = 'anonymous'; // avoid security error
image_bis.onload = function(){
ctx.drawImage(image_bis,0,0,image_width,image_height);
var imageData = ctx.getImageData(title_left, title_top, title_width, title_height),
mapPixel = imageData.data;
var red = 0,
green = 0,
blue = 0,
length = 4 * title_width * title_height;
for(var i=0;i<length;i+=4) {
red += mapPixel[i];
green += mapPixel[i+1];
blue += mapPixel[i+2];
}
length = length / 4;
red = Math.round(red/length);
green = Math.round(green/length);
blue = Math.round(blue/length);
// display result, can easily be improved for something more beautiful (e.g. using complementary color) :
title.style.backgroundColor = 'rgb('+red+','+green+','+blue+')';
c.parentNode.removeChild(c);
return true;
}
image_bis.src = image.src;
}
average_color_background(document.getElementById('image'),document.getElementById('h1'));