Files
bentopdf/src/js/logic/pdf-to-tiff.ts
2025-12-02 22:07:25 +01:00

75 lines
2.2 KiB
TypeScript

import { showLoader, hideLoader, showAlert } from '../ui.js';
import { downloadFile, readFileAsArrayBuffer, getPDFDocument } from '../utils/helpers.js';
import { state } from '../state.js';
import JSZip from 'jszip';
import UTIF from 'utif';
import * as pdfjsLib from 'pdfjs-dist';
import { PDFPageProxy } from 'pdfjs-dist';
pdfjsLib.GlobalWorkerOptions.workerSrc = new URL('pdfjs-dist/build/pdf.worker.min.mjs', import.meta.url).toString();
export async function pdfToTiff() {
showLoader('Converting PDF to TIFF...');
try {
const pdf = await getPDFDocument(
await readFileAsArrayBuffer(state.files[0])
).promise;
if(pdf.numPages === 1) {
const page = await pdf.getPage(1);
const tiffBuffer = await pageToBlob(page);
downloadFile(tiffBuffer, getCleanFilename() + '.tiff');
} else {
const zip = new JSZip();
for (let i = 1; i <= pdf.numPages; i++) {
const page = await pdf.getPage(i);
const tiffBuffer = await pageToBlob(page);
zip.file(`page_${i}.tiff`, tiffBuffer);
}
const zipBlob = await zip.generateAsync({ type: 'blob' });
downloadFile(zipBlob, getCleanFilename() + '_tiffs.zip');
}
} catch (e) {
console.error(e);
showAlert(
'Error',
'Failed to convert PDF to TIFF. The file might be corrupted.'
);
} finally {
hideLoader();
}
}
async function pageToBlob(page: PDFPageProxy): Promise<Blob> {
const viewport = page.getViewport({ scale: 2.0 }); // Use 2x scale for high quality
const canvas = document.createElement('canvas');
const context = canvas.getContext('2d');
canvas.height = viewport.height;
canvas.width = viewport.width;
await page.render({
canvasContext: context,
viewport: viewport,
canvas: canvas,
}).promise;
const imageData = context.getImageData(0, 0, canvas.width, canvas.height);
const rgba = imageData.data;
const tiffBuffer = UTIF.encodeImage(
new Uint8Array(rgba),
canvas.width,
canvas.height
);
return new Blob([tiffBuffer]);
}
function getCleanFilename(): string {
let clean = state.files[0].name.replace(/\.pdf$/i, '').trim();
if (clean.length > 80) {
clean = clean.slice(0, 80);
}
return clean;
}