@e-group/utils/preProcessImage/getOrientation.js

eGroup team utils that share across projects.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = getOrientation;

/**
 * Get orientation of image.
 * https://stackoverflow.com/questions/7584794/accessing-jpeg-exif-rotation-data-in-javascript-on-the-client-side/32490603#32490603
 *
 * @param {File} file image file prepare for uplaod
 */
function getOrientation(file) {
  return new Promise((resolve, reject) => {
    const reader = new FileReader();

    reader.onload = function (e) {
      try {
        const view = new DataView(e.target.result);

        if (view.getUint16(0, false) !== 0xffd8) {
          return resolve(-2);
        }

        const length = view.byteLength;
        let offset = 2;

        while (offset < length) {
          if (view.getUint16(offset + 2, false) <= 8) return resolve(-1);
          const marker = view.getUint16(offset, false);
          offset += 2;

          if (marker === 0xffe1) {
            if (view.getUint32(offset += 2, false) !== 0x45786966) {
              return resolve(-1);
            }

            const little = view.getUint16(offset += 6, false) === 0x4949;
            offset += view.getUint32(offset + 4, little);
            const tags = view.getUint16(offset, little);
            offset += 2;

            for (let i = 0; i < tags; i++) {
              if (view.getUint16(offset + i * 12, little) === 0x0112) {
                return resolve(view.getUint16(offset + i * 12 + 8, little));
              }
            }
          } else if ((marker & 0xff00) !== 0xff00) {
            break;
          } else {
            offset += view.getUint16(offset, false);
          }
        }

        return resolve(-1);
      } catch (error) {
        reject(error);
      }
    };

    reader.readAsArrayBuffer(file);
  });
}