pdf-lib
Version:
Create and modify PDF files with JavaScript
96 lines • 3.76 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
var tslib_1 = require("tslib");
// prettier-ignore
var MARKERS = [
0xffc0, 0xffc1, 0xffc2,
0xffc3, 0xffc5, 0xffc6,
0xffc7, 0xffc8, 0xffc9,
0xffca, 0xffcb, 0xffcc,
0xffcd, 0xffce, 0xffcf,
];
var ColorSpace;
(function (ColorSpace) {
ColorSpace["DeviceGray"] = "DeviceGray";
ColorSpace["DeviceRGB"] = "DeviceRGB";
ColorSpace["DeviceCYMK"] = "DeviceCYMK";
})(ColorSpace || (ColorSpace = {}));
var ChannelToColorSpace = {
1: ColorSpace.DeviceGray,
3: ColorSpace.DeviceRGB,
4: ColorSpace.DeviceCYMK,
};
/**
* A note of thanks to the developers of https://github.com/foliojs/pdfkit, as
* this class borrows from:
* https://github.com/devongovett/pdfkit/blob/e71edab0dd4657b5a767804ba86c94c58d01fbca/lib/image/jpeg.coffee
*/
var JpegEmbedder = /** @class */ (function () {
function JpegEmbedder(imageData, bitsPerComponent, width, height, colorSpace) {
this.imageData = imageData;
this.bitsPerComponent = bitsPerComponent;
this.width = width;
this.height = height;
this.colorSpace = colorSpace;
}
JpegEmbedder.for = function (imageData) {
return tslib_1.__awaiter(this, void 0, void 0, function () {
var dataView, soi, pos, marker, bitsPerComponent, height, width, channelByte, channelName, colorSpace;
return tslib_1.__generator(this, function (_a) {
dataView = new DataView(imageData.buffer);
soi = dataView.getUint16(0);
if (soi !== 0xffd8)
throw new Error('SOI not found in JPEG');
pos = 2;
while (pos < dataView.byteLength) {
marker = dataView.getUint16(pos);
pos += 2;
if (MARKERS.includes(marker))
break;
pos += dataView.getUint16(pos);
}
if (!MARKERS.includes(marker))
throw new Error('Invalid JPEG');
pos += 2;
bitsPerComponent = dataView.getUint8(pos++);
height = dataView.getUint16(pos);
pos += 2;
width = dataView.getUint16(pos);
pos += 2;
channelByte = dataView.getUint8(pos++);
channelName = ChannelToColorSpace[channelByte];
if (!channelName)
throw new Error('Unknown JPEG channel.');
colorSpace = channelName;
return [2 /*return*/, new JpegEmbedder(imageData, bitsPerComponent, width, height, colorSpace)];
});
});
};
JpegEmbedder.prototype.embedIntoContext = function (context, ref) {
return tslib_1.__awaiter(this, void 0, void 0, function () {
var xObject;
return tslib_1.__generator(this, function (_a) {
xObject = context.stream(this.imageData, {
Type: 'XObject',
Subtype: 'Image',
BitsPerComponent: this.bitsPerComponent,
Width: this.width,
Height: this.height,
ColorSpace: this.colorSpace,
Filter: 'DCTDecode',
});
if (ref) {
context.assign(ref, xObject);
return [2 /*return*/, ref];
}
else {
return [2 /*return*/, context.register(xObject)];
}
return [2 /*return*/];
});
});
};
return JpegEmbedder;
}());
exports.default = JpegEmbedder;
//# sourceMappingURL=JpegEmbedder.js.map