// ==UserScript==
// @name         刺猬猫VIP章节图片去水印
// @namespace    http://tampermonkey.net/
// @version      0.3
// @description  去除刺猬猫VIP章节图片上烦人的水印
// @author       菜姬
// @match        *://www.ciweimao.com/chapter/*
// @grant        none
// ==/UserScript==
(async function () {
'use strict';
// Your code here...
let threshold = 192;
function image2line(img) {
const canvas = document.createElement("canvas");
canvas.width = img.naturalWidth;
canvas.height = img.naturalHeight;
const ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0);
filter(canvas, ctx, threshold);
return canvas.toDataURL();
}
async function imageUrl2line(url) {
return new Promise((resolve) => {
const img = new Image();
img.onload = () => {
resolve(image2line(img));
};
img.src = url;
});
}
function filter(canvas, c, threshold) {
let imgData = c.getImageData(0, 0, canvas.width, canvas.height);
let backgroudR = imgData.data[0];
let backgroudG = imgData.data[1];
let backgroudB = imgData.data[2];
for (let i = 0; i < imgData.data.length; i += 4) {
let R = imgData.data[i]; //R(0-255)
let G = imgData.data[i + 1]; //G(0-255)
let B = imgData.data[i + 2]; //B(0-255)
// let Alpha = imgData.data[i + 3]; //Alpha(0-255)
if (R > threshold && G > threshold && B > threshold) {
imgData.data[i] = backgroudR;
imgData.data[i + 1] = backgroudG;
imgData.data[i + 2] = backgroudB;
imgData.data[i + 3] = 255;
}
}
c.putImageData(imgData, 0, 0);
}
let imageDom = document.getElementById("J_BookImage");
if (imageDom)
{
const url = imageDom.style["background-image"].match(/(?:url\(")?(.+)(?:"\))?/)[1];
const line = await imageUrl2line(url);
imageDom.style["background-image"] = `url(${line})`;
}
})();