Some PDF provides simple to use free utilities for converting PDF documents to various file-formats like Word, HTML, and Text, their PDF Image Extractor utility lets you extract images from pdf files and save them to JPEG, GIF, TIFF, BMP, PNG, TGA, PBM, or PPM image formats.
The PDF image extractor utility supports encrypted PDF files and allows batch operations, you simply select the files and output folder and you are ready for the image extraction.