You will need: Firefox, Adοbe Flash Prο and Phοtoshop (or an image converter)
1. Using Firefox,1 open and save the web page with the flash protected images as Web Page, complete (*.htm;*.html).
2. Start Flash Pro, and go to Create new > ActionScript 2.0 or ActionScript 3.0.
3. Go to File > Import > Import to Library or Import to Stage. Locate the swf file and open it. Then navigate to the Library panel. There will be a list of items that make up your swf file. Select the bitmap you would like to extract. Right click it and select Edit with Photoshop. This will open the selected image in Photoshop whereupon you can save the image as png, jpeg, etc files.
If you don’t have Photoshop, you can export selected images as fxg files. You can then convert the fxg files to svg or png files. There may also be a direct way to export selected images as png files nested somewhere in the Flash file menu.
Decompiling items in flash file
Click to enlarge (1146 x 611 x 24 BPP, 712.78 KB)
1 I tried saving web pages as Webpage, Complete in Chrome, but for some reason Chrome can’t save swf files…?
Most of my google search results yielded little information on how to extract swf images. Some of them even incorrectly stated that it was impossible. The following sites, however, especially the stackoverflow sites, were really helpful. If you don’t feel like installing Flash Pro, you could try the trial version of Sothink Flash Decompiler. I’ve never tried it, so I don’t know if it works, though.