If the files are protected by hotlinking, server-side script, flash players then you will not be able to download them. If that's not the case you can use a download accelerator/manager because many of these have the possibility to create a gallery for downloaded files or simply grab the download URL. For this kind of job I recommend you use Internet Download Manager because it has all the features I mentioned earlier. Download and install the application, then visit the page with the pictures, right click an empty spot and select to download only images. After you download them all navigate to the Task menu and select Export > Download queue (As text) and choose a location. All the URLs of your downloaded files will be stored in a plain text file in a location of choice.