CyberChef/src/core/operations/DitherImage.mjs

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2019-02-20 10:20:38 +01:00
/**
* @author j433866 [j433866@gmail.com]
* @copyright Crown Copyright 2019
* @license Apache-2.0
*/
import Operation from "../Operation";
import OperationError from "../errors/OperationError";
import Magic from "../lib/Magic";
import { toBase64 } from "../lib/Base64";
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 = "byteArray";
this.outputType = "byteArray";
this.presentType = "html";
this.args = [];
}
/**
* @param {byteArray} input
* @param {Object[]} args
* @returns {byteArray}
*/
run(input, args) {
const type = Magic.magicFileType(input);
if (type && type.mime.indexOf("image") === 0){
return new Promise((resolve, reject) => {
jimp.read(Buffer.from(input))
.then(image => {
image
.dither565()
.getBuffer(jimp.AUTO, (error, result) => {
if (error){
reject(new OperationError("Error getting the new image buffer"));
} else {
resolve([...result]);
}
});
})
.catch(err => {
reject(new OperationError("Error applying a dither effect to the image."));
});
});
} else {
throw new OperationError("Invalid file type.");
}
}
/**
* Displays the dithered image using HTML for web apps
*
* @param {byteArray} data
* @returns {html}
*/
present(data) {
if (!data.length) return "";
let dataURI = "data:";
const type = Magic.magicFileType(data);
if (type && type.mime.indexOf("image") === 0){
dataURI += type.mime + ";";
} else {
throw new OperationError("Invalid file type.");
}
dataURI += "base64," + toBase64(data);
return "<img src='" + dataURI + "'>";
}
}
export default DitherImage;