index.js

/*jshint laxbreak:true */

var sizeParser = require('filesize-parser');
var exec = require('child_process').exec,
  child;

module.exports = function (path, opts, cb) {
  if (!cb) {
    cb = opts;
    opts = {};
  }

  var cmd = module.exports.cmd(path, opts);
  opts.timeout = opts.timeout || 5000;

  exec(cmd, opts, function (e, stdout, stderr) {
    if (e) {
      return cb(e);
    }
    if (stderr) {
      return cb(new Error(stderr));
    }

    return cb(null, module.exports.parse(path, stdout, opts));
  });
};

module.exports.cmd = function (path, opts) {
  opts = opts || {};
  var format = [
    'name=',
    'size=%[size]',
    'format=%m',
    'colorspace=%[colorspace]',
    'height=%[height]',
    'width=%[width]',
    'orientation=%[orientation]', (opts.exif ? '%[exif:*]' : '')
  ].join("\n");

  var quiet = opts.quiet ? ' -quiet' : '';

  return 'identify' + quiet + ' -format "' + format + '" ' + path;
};

module.exports.parse = function (path, stdout, opts) {
  var lines = stdout.split('\n');
  var ret = {
    path: path
  };
  var i;

  for (i = 0; i < lines.length; i++) {
    if (lines[i]) {
      lines[i] = lines[i].split('=');

      // Parse exif metadata keys
      if (lines[i][0].substr(0, 5) === 'exif:') {
        if (!ret.exif) {
          ret.exif = {};
        }

        ret.exif[lines[i][0].substr(5)] = lines[i][1];

        // Parse normal metadata keys
      }
      else {
        ret[lines[i][0]] = lines[i][1];
      }
    }
  }

  if (ret.width) {
    ret.width = parseInt(ret.width, 10);
  }
  if (ret.height) {
    ret.height = parseInt(ret.height, 10);
  }

  if (ret.size) {
    if (ret.size.substr(ret.size.length - 2) === 'BB') {
      ret.size = ret.size.substr(0, ret.size.length - 1);
    }

    ret.size = parseInt(sizeParser(ret.size));
  }

  if (ret.colorspace && ret.colorspace === 'sRGB') {
    ret.colorspace = 'RGB';
  }

  if (ret.orientation === 'Undefined') {
    ret.orientation = '';
  }

  if (opts && opts.autoOrient && (ret.orientation === 'LeftTop' ||  ret.orientation === 'RightTop' ||  ret.orientation === 'LeftBottom' ||  ret.orientation === 'RightBottom')) {

    ret.width = ret.width + ret.height;
    ret.height = ret.width - ret.height;
    ret.width = ret.width - ret.height;
  }

  return ret;
};