covid-green-dcc-file-decoder
Version:
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111 lines (110 loc) • 4.78 kB
JavaScript
;
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } });
}) : (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
o[k2] = m[k];
}));
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
o["default"] = v;
});
var __importStar = (this && this.__importStar) || function (mod) {
if (mod && mod.__esModule) return mod;
var result = {};
if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k);
__setModuleDefault(result, mod);
return result;
};
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.extractQRFromPDF = void 0;
// eslint-disable-next-line
const pdfjsLib = __importStar(require("pdfjs-dist/legacy/build/pdf"));
// import workerEntry from 'pdfjs-dist/legacy/build/pdf.worker.entry'
const canvas_1 = __importDefault(require("canvas"));
const util_1 = require("../util");
const _1 = require("./");
// Some PDFs need external cmaps.
const CMAP_URL = '../../node_modules/pdfjs-dist/cmaps';
const CMAP_PACKED = true;
// pdfjsLib.GlobalWorkerOptions.workerSrc = workerEntry
// eslint-disable-next-line
function NodeCanvasFactory() { }
NodeCanvasFactory.prototype = {
create: function NodeCanvasFactory_create(width, height) {
const canvas = canvas_1.default.createCanvas(width, height);
const context = canvas.getContext('2d');
return {
canvas,
context,
};
},
reset: function NodeCanvasFactory_reset(canvasAndContext, width, height) {
canvasAndContext.canvas.width = width;
canvasAndContext.canvas.height = height;
},
destroy: function NodeCanvasFactory_destroy(canvasAndContext) {
// Zeroing the width and height cause Firefox to release graphics
// resources immediately, which can greatly reduce memory consumption.
canvasAndContext.canvas.width = 0;
canvasAndContext.canvas.height = 0;
canvasAndContext.canvas = null;
canvasAndContext.context = null;
},
};
function extractQRFromPDF(pdf, scaleFactor) {
return __awaiter(this, void 0, void 0, function* () {
// convert pdf to image
// eslint-disable-next-line
const pdfDoc = yield pdfjsLib.getDocument({
data: pdf,
cMapUrl: CMAP_URL,
cMapPacked: CMAP_PACKED,
}).promise;
// we will read max 3 pages from a pdf
const pageMax = Math.min(pdfDoc.numPages, 1);
let pageCount = 1;
let qrData;
while (!qrData && pageCount <= pageMax) {
const page = yield pdfDoc.getPage(pageCount);
// Render the page on a Node canvas with 100% scale.
const viewport = page.getViewport({ scale: scaleFactor });
const canvasFactory = new NodeCanvasFactory();
const canvasAndContext = canvasFactory.create(viewport.width, viewport.height);
const renderContext = {
canvasContext: canvasAndContext.context,
viewport,
canvasFactory,
};
yield page.render(renderContext).promise;
const image = canvasAndContext.canvas.toBuffer();
try {
qrData = yield _1.extractQRFromImage(image);
}
catch (e) {
// no image in page
console.log(e, 'Decode Image Exception');
}
pageCount += 1;
}
if (!qrData || qrData.length === 0) {
throw util_1.qrNotDetected();
}
return qrData;
});
}
exports.extractQRFromPDF = extractQRFromPDF;