If you don’t have Pdf Merging Online ’s Pdf Merging Online PDF Editor, you can use Word, LibreOffice Writer, Google Doc, or other capable word-processor to insert the images on a page or pages. Then export the document to a PDF. That usually works OK, and I think it’s how most students get their assignments to me as PDFs. Pdf Merging Online allows for better precision in the graphics and fonts, and has other features like ‘fillable forms’, but most PDFs are OK exported from a word processor or multi-tabbed spreadsheet. It’s admirable that you want to make a PDF with the images. I think it’s plain rude to send somebody a bunch of images and make them assemble the presentation themselves. If a student sends me a dozen separate files for an assignment I reject it and ask for them to be in a single PDF. I also think it’s rude to send a .doc, .docx, .xls, .vsd or other proprietary file format since there are lots of people that don’t have those tools. I don’t keep MSOffice on my machines and wish my colleagues would put stuff into a PDF. The P stands for Portable, it’s practically The Standard, and practically every device known to man can render a PDF.
If you want to use a PDF editor only to convert PDFs to images, you can use Photoshop. You can use Adobe Reader, if it's not an externality, but it offers the same functionality as Adobe Acrobat. For Windows users, PDF Studio is recommended, as it converts PDF files, so you can open in Microsoft Office and then convert to PDF. For Mac users, Preview PDF Creator is recommended, you can create PDF and convert PDF with this program, too. For Linux users, PDF Converter FCE is recommended, as it allows converting PDF to PDF from and to JPEG/TIFF. For Mac OS X Users, there is no direct PDF converter on OS X, as PDF is converted to a PDF image with a plugin and can be opened in Preview for Mac, however, it lacks OCR. You can use PDF Converter, which is a free one, works great, as.