mirror of https://github.com/gchq/CyberChef.git
88 lines
2.3 KiB
JavaScript
88 lines
2.3 KiB
JavaScript
/**
|
|
* @author j433866 [j433866@gmail.com]
|
|
* @copyright Crown Copyright 2019
|
|
* @license Apache-2.0
|
|
*/
|
|
|
|
import Operation from "../Operation.mjs";
|
|
import OperationError from "../errors/OperationError.mjs";
|
|
import { isImage } from "../lib/FileType.mjs";
|
|
import { toBase64 } from "../lib/Base64.mjs";
|
|
import { isWorkerEnvironment } from "../Utils.mjs";
|
|
import jimp from "jimp";
|
|
|
|
/**
|
|
* Image Dither operation
|
|
*/
|
|
class DitherImage extends Operation {
|
|
|
|
/**
|
|
* DitherImage constructor
|
|
*/
|
|
constructor() {
|
|
super();
|
|
|
|
this.name = "Dither Image";
|
|
this.module = "Image";
|
|
this.description = "Apply a dither effect to an image.";
|
|
this.infoURL = "https://wikipedia.org/wiki/Dither";
|
|
this.inputType = "ArrayBuffer";
|
|
this.outputType = "ArrayBuffer";
|
|
this.presentType = "html";
|
|
this.args = [];
|
|
}
|
|
|
|
/**
|
|
* @param {ArrayBuffer} input
|
|
* @param {Object[]} args
|
|
* @returns {byteArray}
|
|
*/
|
|
async run(input, args) {
|
|
if (!isImage(input)) {
|
|
throw new OperationError("Invalid file type.");
|
|
}
|
|
|
|
let image;
|
|
try {
|
|
image = await jimp.read(input);
|
|
} catch (err) {
|
|
throw new OperationError(`Error loading image. (${err})`);
|
|
}
|
|
try {
|
|
if (isWorkerEnvironment())
|
|
self.sendStatusMessage("Applying dither to image...");
|
|
image.dither565();
|
|
|
|
let imageBuffer;
|
|
if (image.getMIME() === "image/gif") {
|
|
imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
|
|
} else {
|
|
imageBuffer = await image.getBufferAsync(jimp.AUTO);
|
|
}
|
|
return imageBuffer.buffer;
|
|
} catch (err) {
|
|
throw new OperationError(`Error applying dither to image. (${err})`);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Displays the dithered image using HTML for web apps
|
|
* @param {ArrayBuffer} data
|
|
* @returns {html}
|
|
*/
|
|
present(data) {
|
|
if (!data.byteLength) return "";
|
|
const dataArray = new Uint8Array(data);
|
|
|
|
const type = isImage(dataArray);
|
|
if (!type) {
|
|
throw new OperationError("Invalid file type.");
|
|
}
|
|
|
|
return `<img src="data:${type};base64,${toBase64(dataArray)}">`;
|
|
}
|
|
|
|
}
|
|
|
|
export default DitherImage;
|