Img.vision - Image hosting & video hosting for eCommerce sellers
pdflayer - Free, powerful HTML to PDF API supporting both URL and raw HTML conversion. Unlimited document size, lightning-fast and compatible PHP, Python, Ruby, etc.
UploadHouse - Thumbnail and resize your photos and images
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
ImageVenue - ImageVenue is a great online hosting service that allows uploading pictures for showing creative works with a simple-to-use technique.
Tcpdf - TCPDF: Open Source PHP Class for generating PDF documents