PDF Embed API - Limitation on high-resolution PDFs

  I have a single-page PDF file with a page size of 11 x 17.  It was created from a JPEG image with a resolution of 7649 x 4950 pixels (450 dpi).  I configured Acrobat Pro to use maximum image quality when creating the PDF and it produced a 37 MB file.  When I view the PDF zoomed in using Acrobat Pro, I judge the image to be the same resolution as the JPEG and even if I were wrong about that, the quality of the PDF image exceeds my requirement.

  However when I open this PDF in the embedded viewer, the maximum zoom is 4.16 and when fully zoomed in the image is only 5092 x 3310 and readability is impaired.  I queried the image size using the Firefox debugger and the API's scrolling events report the same canvas size.  When I create a PDF from a smaller 8.5 x 11 image at the same 450 dpi resolution, the width of the canvas is only slightly reduced, 94%, versus the 66% reduced width of the 11 x 17. 

  Is there an upper limit for the size or resolution of a PDF page in the embedded viewer?   The reduction in image size is making a critical difference and I need to preserve the resolution of the original JPEG.  Splitting the image into 2 separate pages is not an option.    

  I wish I could zoom in slightly past 100%, say 133%.  The quality and content of the image could withstand the additional magnification without objectionable distortion and the readability would be improved.  I know I could expand the image using Photoshop, but I don't think this would solve my current problem with reduced image size.