最近有点迷各种古书,然后从 www.shuge.org 下载了各种高清的印本,快成db狂魔了...上面也有人在各种平台上分享,不胜感激...只是有些平台可以免费看但是没法下载... 反正你都canvas了,撸下来自己珍藏...
于是让qwen写了一段代码:
write a javascript function to trigger download a picture from a canvas image data. i mean there is a canvas with sth painted. i'd like to have a function to get its image data and convert the raw data into for example png file data array and trigger downloading the file from memory.
js
function downloadCanvasImage(canvas, filename = 'canvas-image.png', format = 'png') {
// Get the image data URL from the canvas
const mimeType = format === 'png' ? 'image/png' : 'image/jpeg';
const dataURL = canvas.toDataURL(mimeType);
// Create a temporary link element
const link = document.createElement('a');
link.href = dataURL;
link.download = filename;
// Append the link to the body (required for Firefox)
document.body.appendChild(link);
// Programmatically click the link to trigger the download
link.click();
// Remove the link from the DOM
document.body.removeChild(link);
}
之后
js
const list = document.querySelectorAll('canvas.<classname>');
for (let i = 0; i < list.length; i ++) {
downloadCanvasImage(list[i], `page${i+1}.png`);
}
然后再一个 image-to-pdf
就可以变成pdf存档了。大书库又多了几百GB...
把各种迷信的命相卜书籍看完,大致了解了古代历法五行阴阳历干支历(圭表测影、十月历、六龙历...),易经卦象...开始再看一遍医书,启动第二遍理解...