code: function getImageDimensions(metaData) {
      var fetch = {
          coverImage: imageLib.imageSizeCache(metaData.coverImage.url),
          authorImage: imageLib.imageSizeCache(metaData.authorImage.url),
          ogImage: imageLib.imageSizeCache(metaData.ogImage.url),
          logo: imageLib.imageSizeCache(metaData.blog.logo.url)
      };
  
      return Promise
          .props(fetch)
          .then(function (imageObj) {
              _.forEach(imageObj, function (key, value) {
                  if (_.has(key, 'width') && _.has(key, 'height')) {
                      // We have some restrictions for publisher.logo:
                      // The image needs to be <=600px wide and <=60px high (ideally exactly 600px x 60px).
                      // Unless we have proper image-handling (see https://github.com/TryGhost/Ghost/issues/4453),
                      // we will fake it in some cases or not produce an imageObject at all.
                      if (value === 'logo') {
                          if (key.height <= 60 && key.width <= 600) {
                              _.assign(metaData.blog[value], {
                                  dimensions: {
                                      width: key.width,
                                      height: key.height
                                  }
                              });
                          } else if (key.width === key.height) {
                              // CASE: the logo is too large, but it is a square. We fake it...
                              _.assign(metaData.blog[value], {
                                  dimensions: {
                                      width: 60,
                                      height: 60
                                  }
                              });
                          }
                      } else {
                          _.assign(metaData[value], {
                              dimensions: {
                                  width: key.width,
                                  height: key.height
                              }
                          });
                      }
                  }
              });
  
              return metaData;
          });
  }
docs: Get Image dimensions
  @param {object} metaData
  @returns {object} metaData
  @description for image properties in meta data (coverImage, authorImage and blog.logo), `getCachedImageSizeFromUrl` is
  called to receive image width and height