Use javascript to automate rotating a background image in Adobe Acrobat 2017?

Hi all.  I have Adobe Acrobat 2017 and I am new to running actions but trying to learn.  I have a pdf where the background image is sourced from a file and I need to rotate the image 270 degrees for the landscape pages only.  I'd like to use javascript to automate this process.  I found code to step through the document and find the landscape pages, but I can't figure out how to reference and rotate the background image.  Can someone help? 

/* Finds all landscape pages in current document */

var LandscapePageCount = 0;

{

    for (PageIndex = 0; PageIndex <= this.numPages - 1; PageIndex++)

    {

        // check if this page is landscape or portrait

        var aRect = this.getPageBox("Media",PageIndex);

        var PageWidth = aRect[2] - aRect[0];

        var PageHeight = aRect[1] - aRect[3];

        if (PageHeight < PageWidth)  // Landscape page found

        {

            LandscapePageCount++;

            // NEED HELP HERE

        }

    }   

    app.alert("Total number of landscape pages found: " + LandscapePageCount, 3);

}