int DocumentID = qp.LoadFromFile(fullFileName, "");
int iNumPages = qp.PageCount();

 

for (int i = 1; i <= iNumPages; i++)
{
    tmpTNFilename = Set thumbnail filename for this page

 

    qp.SelectPage(i);
    qp.NormalizePage(0);

 

    // Gave me just part of the lower left corner
    //sizeDouble = QPDFUtilities.GetImageSize(qp, thumbnailData);
    //qp.SetPageDimensions(sizeDouble.WidthDouble, sizeDouble.HeightDouble);

 

    // When opened in a viewer still gives me a full page and the file size is too large
    //qp.SetPageThumbnail();

 

    // When opened in a viewer still gives me a full page and the file size is too large
    scale = QPDFUtilities.GetImageScale(qp, thumbnailData);
    qp.SetScale(scale);

 

    qp.RenderPageToFile(96, i, 1, tmpTNFilename);
    thumbnailData.ThumbnailPaths.Add(tmpTNFilename);
}

 

qp.RemoveDocument(DocumentID);

 

So what I am seeing is the resulting file size is too large and the image when displayed in a viewer is still a full page.  Recommendations as to how I can use your available API to achieve the small file size.  Or should I render each page to a JPEG and then just use .Nets System.Drawing.Image to create the thumbnails?