48 lines
1.5 KiB
TypeScript
48 lines
1.5 KiB
TypeScript
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import * as PDFJS from 'pdfjs-dist';
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PDFJS.GlobalWorkerOptions.workerSrc = `./pdf.worker.min.js`;
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export const PDF_MIME_TYPE = 'application/pdf';
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export const PDF_EXTENSION = '.pdf';
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export const IMAGE_MIME_TYPES = ['image/png', 'image/jpeg'];
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export const IMAGE_EXTENSIONS = ['.jpg', '.jpeg', '.png', '.JPG', '.JPEG', '.PNG'];
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export const IMAGE_SIZE_LIMIT = 5 * 1024 * 1024;
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export function isImageFile(file: File) {
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return (
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IMAGE_MIME_TYPES.includes(file.type) &&
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IMAGE_EXTENSIONS.some((ext) => file.name.endsWith(ext))
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);
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}
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export function isPDFFile(file: File) {
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return file.type === PDF_MIME_TYPE && file.name.endsWith(PDF_EXTENSION);
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}
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export function isFileUnderLimit(file: File, limit: number = IMAGE_SIZE_LIMIT) {
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return file.size <= limit;
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}
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export async function pdf2Images(file: File): Promise<File[]> {
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const fileBuffer = await file.arrayBuffer();
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const pdf = await PDFJS.getDocument(fileBuffer).promise;
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const page = await pdf.getPage(1);
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const viewport = page.getViewport({ scale: 1 });
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const canvasContext = document.createElement('canvas').getContext('2d');
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canvasContext.canvas.width = viewport.width;
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canvasContext.canvas.height = viewport.height;
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await page.render({
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viewport,
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canvasContext,
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}).promise;
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const blob = await new Promise<Blob>((resolve) => {
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canvasContext.canvas.toBlob(resolve, 'image/png');
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});
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canvasContext.canvas.remove();
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return [new File([blob], file.name.replace('.pdf', '.png'))];
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}
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