Created
February 11, 2015 02:54
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pdf to image using pdf.js
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| <html> | |
| <body> | |
| <script type="text/javascript" src="//mozilla.github.io/pdf.js/build/pdf.js"></script> | |
| <script type="text/javascript"> | |
| var url = "https://docs.google.com/document/export?format=pdf&id=1ML11ZyyMpnAr6clIAwWrXD53pQgNR-DppMYwt9XvE6s&token=AC4w5Vg7fSWH1Hq0SgNckx4YCvnGPaScyw%3A1423618416864"; | |
| var pages = [], heights = [], width = 0, height = 0, currentPage = 1; | |
| var scale = 1.5; | |
| function draw() { | |
| var canvas = document.createElement('canvas'), ctx = canvas.getContext('2d'); | |
| canvas.width = width; | |
| canvas.height = height; | |
| for(var i = 0; i < pages.length; i++) | |
| ctx.putImageData(pages[i], 0, heights[i]); | |
| document.body.appendChild(canvas); | |
| } | |
| PDFJS.disableWorker = true; // due to CORS | |
| PDFJS.getDocument(url).then(function (pdf) { | |
| getPage(); | |
| function getPage() { | |
| pdf.getPage(currentPage).then(function(page) { | |
| console.log("Printing " + currentPage); | |
| var viewport = page.getViewport(scale); | |
| var canvas = document.createElement('canvas') , ctx = canvas.getContext('2d'); | |
| var renderContext = { canvasContext: ctx, viewport: viewport }; | |
| canvas.height = viewport.height; | |
| canvas.width = viewport.width; | |
| page.render(renderContext).then(function() { | |
| pages.push(ctx.getImageData(0, 0, canvas.width, canvas.height)); | |
| heights.push(height); | |
| height += canvas.height; | |
| if (width < canvas.width) width = canvas.width; | |
| if (currentPage < pdf.numPages) { | |
| currentPage++; | |
| getPage(); | |
| } | |
| else { | |
| draw(); | |
| } | |
| }); | |
| }); | |
| } | |
| }); | |
| </script> | |
| </body> | |
| </html> |
const convertDataUrlToFile = (dataUrl, filename) => {
return fetch(dataUrl)
.then(res => res.arrayBuffer())
.then(buf => new File([buf], filename, { type: 'image/png' }))
};
const convertFiletoDataUrl = (file) => new Promise((resolve, reject) => {
const reader = new FileReader();
reader.readAsDataURL(file);
reader.onload = () => resolve(reader.result.normalize());
reader.onerror = error => reject(error);
});
const convertPdfPageToImage = (pdf, pageNumber, fileName) => new Promise(resolve => {
pdf.getPage(pageNumber).then(page => {
const viewport = page.getViewport({ scale: 1 });
const canvas = document.createElement('canvas');
const ctx = canvas.getContext('2d');
const renderContext = { canvasContext: ctx, viewport: viewport };
canvas.height = viewport.height;
canvas.width = viewport.width;
page.render(renderContext).promise.then(() => {
const dataUrl = canvas.toDataURL();
convertDataUrlToFile(dataUrl, `${fileName}-${pageNumber}.png`).then(resolve);
});
});
})
const convertPdfFilesToImages = (files) => new Promise(resolve => {
pdfjsLib.GlobalWorkerOptions.workerSrc = `//cdnjs.cloudflare.com/ajax/libs/pdf.js/${pdfjsLib.version}/pdf.worker.js`;
const worker = new pdfjsLib.PDFWorker();
const promises = Array.from(Array(files.length), (_, index) => new Promise(resolve => {
const file = files[index];
if (file.type === 'application/pdf') {
convertFiletoDataUrl(file).then(dataUrl =>
pdfjsLib.getDocument({ url: dataUrl, worker }).promise.then(pdf => {
const promises = Array.from(Array(pdf.numPages), (_, index) => new Promise(resolve => {
const pageNumber = index + 1;
convertPdfPageToImage(pdf, pageNumber, file.name).then(resolve);
}));
Promise.all(promises).then(resolve);
})
);
} else {
resolve(file);
}
}));
Promise.all(promises).then(files => resolve(files.flat()));
});
@itamardavidyan this is good script and thanks a lot for that
but i couldn't use it because image quality is very bad🤔
@agoalofalife
In this line you can change scale to enchance quality :D
const viewport = page.getViewport({ scale: 1 });
e.g.
const viewport = page.getViewport({ scale: 4 });
Using angular how to use the above code?
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Hello sir,
I'm beginner in coding world..i'm applying this script for convert pdf to image, but unfortunately, it's wont work.
I see error in console like "PDFJS is not defined" even pdf.js is integrated. what's the solution for this..Please help me to move ahead.
Thanks in advance,
Ankur