batch-image-resize.js

let Jimp = await npm('jimp')

let width = await arg('New width in pixels')

let selectedFiles = await getSelectedFile();
let filePaths = selectedFiles.split("\n");

for (let filePath of filePaths) {
  Jimp.read(filePath, (err, image) => {
    if (err) throw err;
    image.resize(parseInt(width), Jimp.AUTO).write(filePath); // save
  });
}