test-resize.js

'use strict';

const jimp = require('jimp');
const path = require('path');

async function main() {
  const imgPath = process.argv[2];
  const width = +process.argv[3];
  const height = +process.argv[4];
  const watermarkPath = process.argv[5];

  const newImgPath = await resizeImage(imgPath, width, height);
  await watermarkImageCopy(newImgPath, watermarkPath);
}

async function resizeImage(imgPath, width, height) {
  // Checking of input parameters
  if (!imgPath) {
    console.error(
      '!!! Path to the image must be setted as the first parameter.',
    );
    return;
  }
  if (Number.isNaN(width)) {
    console.error(
      '!!! Width for new image must be setted as the second parameter.',
    );
    return;
  }
  height = Number.isNaN(height) ? jimp.AUTO : height;
  const newImgPath =
    path.dirname(imgPath) + path.sep + 'resized_' + path.basename(imgPath);

  const image = await jimp.read(imgPath);
  await image.resize(width, height);
  await image.quality(80);
  await image.writeAsync(newImgPath);
  console.log('Resizing was succesful');

  return newImgPath;
}

async function watermarkImageCopy(destPath, watermarkPath) {
  const newImgPath =
    path.dirname(destPath) +
    path.sep +
    'watermarked_' +
    path.basename(destPath);

  const destImage = await jimp.read(destPath);
  const watermarkImage = await jimp.read(watermarkPath);

  // calc the center of destination image
  const x = destImage.bitmap.width / 2 - watermarkImage.bitmap.width / 2;
  const y = destImage.bitmap.height / 2 - watermarkImage.bitmap.height / 2;

  await destImage.composite(watermarkImage, x, y, {
    opacitySource: 0.5,
  });
  await destImage.writeAsync(newImgPath);
  console.log('Watermarking was succesful');

  return newImgPath;
}

main();