Google Sheets Apps Script > Finding Image Ratio

I'm using the google sheets scripting language, and I want to get the ratio of an image from a web link, e.g. this flag.

I have seen a way to do it here, but I want to return the ratio from the function, not put it in a random cell.

So far I have managed to get this, which doesn't seem to work.

function imageSize(imgUrl) {
  if  (typeof imgUrl == 'undefined') {
    imgUrl = 'http://www.google.com/intl/en_ALL/images/logo.gif';
  }
  PropertiesService.getScriptProperties().setProperty('ratio', 0);

  var t = '';     
  t += '<script>\n';
  t += 'function hd(){\n';
  t += 'var img = new Image();\n';
  t += 'img.onload = function() {\n';
  t += "google.script.run.returnVal(this.width / this.height);\n";
  t += '}\n';
  t += "img.src = '" + imgUrl + "';\n";
  t += '}\n';
  t += 'google.script.run.withSuccessHandler(google.script.host.close)\n';
  t += '.returnVal(hd());\n';
  t += '</script>\n';  


  var output = HtmlService.createHtmlOutput(t);
  // output.setSandboxMode(HtmlService.SandboxMode.IFRAME); 
  // SpreadsheetApp.getUi().showModalDialog(output,'please, wait...');
  // output.clear();
  Utilities.sleep(2000);
  return PropertiesService.getScriptProperties().getProperty('ratio');;
}


function returnVal(h) {
  Logger.log(h);
  PropertiesService.getScriptProperties().setProperty('ratio', h);
  return h;
}

How about this workaround? I think that there are several answers for your situation. So please think of this as one of them. The flow of this script is as follows.

Download the image as a file.
Retrieve imageMediaMetadata from the downloaded file using Drive API.
Delete the downloaded file.
Retrieve the aspect ratio from imageMediaMetadata.

In order to use this sample script, please enable Drive API at Advanced Google Services and API console as follows.

Enable Drive API v2 at Advanced Google Services

On script editor
- Resources -> Advanced Google Services
- Turn on Drive API v2

Enable Drive API at API console

On script editor
- Resources -> Cloud Platform project
- View API console
- At Getting started, click "Explore and enable APIs".
- At left side, click Library.
- At Search for APIs & services, input "Drive". And click Drive API.
- Click Enable button.
- If API has already been enabled, please don't turn off.

Sample script

function myFunction(url) {
  var blob = UrlFetchApp.fetch(url).getBlob();
  var fileId = DriveApp.createFile(blob).getId();
  var imageMediaMetadata = Drive.Files.get(fileId).imageMediaMetadata;
  var aspectRatio = imageMediaMetadata.width / imageMediaMetadata.height;
  Drive.Files.remove(fileId);
  return aspectRatio;
}

Note :

When https://www.theodora.com/flags/e_timor.gif in your question is used for this script, 1.5 is retrieved.

References :

Advanced Google Services
Drive API

If this was not what you want, I'm sorry.

Added :

If you don't want to create files in Google Drive, you can retrieve the aspect ratio using this library. This library can retrieve the image size from a blob, because the binary data of the image is parsed. When this library is used for your situation, the script becomes as follows.

function myFunction(url) {
  var blob = UrlFetchApp.fetch(url).getBlob();
  var res = ImgApp.getSize(blob);
  var aspectRatio = res.width / res.height;
  return aspectRatio;
}