Blue Crab is a versatile and thorough program that you use to copy the contents of a Web site to your computer, in whole or in part, and then search or browse it offline.
With Blue Crab you can download all the content including HTML, PDF, graphics, video, file archives, etc., or use selective filtering to restrict downloads to specific kinds of files. For example, you can choose to save only the JPEG images Blue Crab finds, or just the PDF's.
Blue Crab has a special feature called the "Media Grabber" which you can use to easily download just the images (or movies) on a Web site Moreover, you can view a slide show of the images as they are downloaded. You also have the option of "flattening" the images, i.e., putting them all into one folder, or preserving the folder structure on the server (just as when downloading a complete Web site for offline viewing.)
Blue Crab is always gentle on the server, processing only one URL at a time. (You can even make it pause between successive downloads so as to not overwhelm the server.)
The demo version you download now is fully functionaly and runs for about ten days.
Check the website for bundles and promos.