Convert via region data to yolo format

convert.js

const fs = require("fs");
const path = require("path");
const sizeOf = require("image-size");

const args = process.argv.slice(2);

const data = require(path.join(path.resolve(args[0]), "/via_region_data.json"));

const imgMetadata = Object.values(data["_via_img_metadata"]);

const firstFour = list => list.slice(0, 4);

const sum = list => list.reduce((acc, cur) => acc + cur, 0);

const average = list => Math.round(sum(list) / list.length);

const xListYListToCenterXYHeightWidth = (xList, yList) => {
  const centerX = average(xList);
  const centerY = average(yList);
  const maxX = Math.max(...xList);
  const maxY = Math.max(...yList);
  const minX = Math.min(...xList);
  const minY = Math.min(...yList);
  const width = maxX - minX;
  const height = maxY - minY;
  return { centerX, centerY, width, height };
};

imgMetadata.forEach(({ filename, regions }) => {
  const dimensions = sizeOf(path.join(path.resolve(args[0]), filename));
  fs.writeFile(
    path.join(path.resolve(args[0]), filename.split(".")[0] + ".txt"),
    regions
      .map(({ shape_attributes }) => {
        const firstFourX = firstFour(shape_attributes.all_points_x);
        const firstFourY = firstFour(shape_attributes.all_points_y);
        const {
          centerX,
          centerY,
          width,
          height
        } = xListYListToCenterXYHeightWidth(firstFourX, firstFourY);

        return [
          1,
          centerX / dimensions.width,
          centerY / dimensions.height,
          width / dimensions.width,
          height / dimensions.height
        ].join(" ");
      })
      .join("\n"),
    function(err) {
      if (err) {
        return console.log(err);
      }

      console.log("The file was saved!");
    }
  );
});