strapi/packages/strapi-plugin-upload/services/image-manipulation.js

'use strict';
/**
 * Image manipulation functions
 */

const sharp = require('sharp');

const bytesToKbytes = bytes => Math.round((bytes / 1000) * 100) / 100;

const getMetadatas = buffer =>
  sharp(buffer)
    .metadata()
    .catch(() => ({})); // ingore errors

const getDimensions = buffer =>
  getMetadatas(buffer)
    .then(({ width, height }) => ({ width, height }))
    .catch(() => ({})); // ingore errors

const THUMBNAIL_RESIZE_OPTIONS = {
  width: 245,
  height: 156,
  fit: 'inside',
};

const resizeTo = (buffer, options) =>
  sharp(buffer)
    .resize(options)
    .toBuffer()
    .catch(() => null);

const generateThumbnail = async file => {
  const { width, height } = await getDimensions(file.buffer);

  if (width > THUMBNAIL_RESIZE_OPTIONS.width || height > THUMBNAIL_RESIZE_OPTIONS.height) {
    const newBuff = await resizeTo(file.buffer, THUMBNAIL_RESIZE_OPTIONS);

    if (newBuff) {
      const { width, height, size } = await getMetadatas(newBuff);

      return {
        hash: `thumb_${file.hash}`,
        ext: file.ext,
        mime: file.mime,
        width,
        height,
        size: bytesToKbytes(size),
        buffer: newBuff,
      };
    }
  }

  return null;
};

module.exports = {
  getDimensions,
  generateThumbnail,
  bytesToKbytes,
};