image-in-browser/lib/formats/tiff-decoder.js

Package for encoding / decoding images, transforming images, applying filters, drawing primitives on images on the client side (no need for server Node.js)

import { InputBuffer } from '../common/input-buffer.js';
import { ExifData } from '../exif/exif-data.js';
import { FrameType } from '../image/frame-type.js';
import { ImageFormat } from './image-format.js';
import { TiffImage } from './tiff/tiff-image.js';
import { TiffInfo } from './tiff/tiff-info.js';
export class TiffDecoder {
    constructor() {
        this._info = undefined;
        this._exifData = undefined;
    }
    get info() {
        return this._info;
    }
    get exifData() {
        return this._exifData;
    }
    get format() {
        return ImageFormat.tiff;
    }
    get numFrames() {
        return this._info !== undefined ? this._info.images.length : 0;
    }
    readHeader(p) {
        const byteOrder = p.readUint16();
        if (byteOrder !== TiffDecoder._tiffLittleEndian &&
            byteOrder !== TiffDecoder._tiffBigEndian) {
            return undefined;
        }
        let bigEndian = false;
        if (byteOrder === TiffDecoder._tiffBigEndian) {
            p.bigEndian = true;
            bigEndian = true;
        }
        else {
            p.bigEndian = false;
            bigEndian = false;
        }
        let signature = 0;
        signature = p.readUint16();
        if (signature !== TiffDecoder._tiffSignature) {
            return undefined;
        }
        let offset = p.readUint32();
        const ifdOffset = offset;
        const p2 = InputBuffer.from(p);
        p2.offset = offset;
        const images = [];
        while (offset !== 0) {
            let img = undefined;
            try {
                img = new TiffImage(p2);
                if (!img.isValid) {
                    break;
                }
            }
            catch (error) {
                break;
            }
            images.push(img);
            offset = p2.readUint32();
            if (offset !== 0) {
                p2.offset = offset;
            }
        }
        return images.length > 0
            ? new TiffInfo({
                bigEndian: bigEndian,
                signature: signature,
                ifdOffset: ifdOffset,
                images: images,
            })
            : undefined;
    }
    isValidFile(bytes) {
        const buffer = new InputBuffer({
            buffer: bytes,
        });
        return this.readHeader(buffer) !== undefined;
    }
    startDecode(bytes) {
        this._input = new InputBuffer({
            buffer: bytes,
        });
        this._info = this.readHeader(this._input);
        if (this.info !== undefined) {
            const buffer = new InputBuffer({
                buffer: bytes,
            });
            this._exifData = ExifData.fromInputBuffer(buffer);
        }
        return this._info;
    }
    decodeFrame(frameIndex) {
        if (this._info === undefined) {
            return undefined;
        }
        const image = this._info.images[frameIndex].decode(this._input);
        if (this._exifData !== undefined) {
            image.exifData = this._exifData;
        }
        return image;
    }
    decode(opt) {
        var _a;
        const bytes = opt.bytes;
        this._input = new InputBuffer({
            buffer: bytes,
        });
        this._info = this.readHeader(this._input);
        if (this._info === undefined) {
            return undefined;
        }
        const len = this.numFrames;
        if (len === 1 || opt.frameIndex !== undefined) {
            return this.decodeFrame((_a = opt.frameIndex) !== null && _a !== void 0 ? _a : 0);
        }
        const image = this.decodeFrame(0);
        if (image === undefined) {
            return undefined;
        }
        image.exifData = ExifData.fromInputBuffer(new InputBuffer({
            buffer: bytes,
        }));
        image.frameType = FrameType.page;
        for (let i = 1; i < len; ++i) {
            const frame = this.decodeFrame(i);
            image.addFrame(frame);
        }
        return image;
    }
}
TiffDecoder._tiffSignature = 42;
TiffDecoder._tiffLittleEndian = 0x4949;
TiffDecoder._tiffBigEndian = 0x4d4d;
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