From Starflower Software:
Pdf-No-Img is a freeware tool for viewing PDF documents without the images. When you open a .pdf file using this tool, image objects in the document are replaced by a simple gray box. Pdf-No-Img is not a PDF viewer itself, it only creates a temporary "no-image version" that is then displayed by your default PDF viewer as usual. Pdf-No-Img hides only image objects, it does not hide vector graphics and inline images.