Blizzard had a really cool idea to produce big images of their official Warcraft II maps and offer them for download. You can take advantage of this to see player start locations and resources, find your way around a map quickly, or look for possible PUDs to try out. They did a similar program for Starcraft maps and have quite a few up on the Starcraft Compendium.
Problem is, these map images are actually pretty low-quality: they have been resized down from the original, they suffer from JPEG blurriness, some don't show every player, and they are created once the game has already started (which means some computer players have already started building, mining, or chopping). Moreover, they don't form a complete set: there aren't images available for all the maps included with the game (let alone the three official bonus maps Blizzard later released). They may suit your needs if you just want a quick preview on-screen, but anyone wanting to study them in detail or print them out would find the collection sorely lacking.
To create a good set of map images, I produced a tool that can generate full-size map images from a PUD, provided you've extracted the required resources from your War2 BNE mpq file into the appropriate directory. It produces a big (up to 4096x4096) true-color BMP image which is then run through OptiPNG to make lossless 8bpp compressed PNG images. The resulting files are ~250kb for a 32x32 PUD, ~600kb for 64x64, ~1500kb for 96x96, and ~2200kb for 128x128.
This ZIP file is the complete collection of PUD images for all maps included with Warcraft II BNE (patch 2.02) as well as the three 'official' bonus maps linked above. It is sorted by directory exactly as you'd find your Maps/ folder. For each map there is a PNG image as well as a TXT that briefly describes the map name, description, size, tileset, player numbers and player starting conditions. Click here to get it [220 MB] - warning, it's a BIG file and will take some time to download.
Additionally, I've produced a set of PNG images for fans of the KPUDS map set. Click here for the images [142 MB] (again, really big file!)
The tool I wrote to do this is called pud2bmp. I release it under the GPL v3, although the code isn't that great. It requires you to extract the Art resources for bgs and units to the local directory from your MPQ (e.g. art/bgs/forest, art/bgs/iceland, art/unit/human, etc). If you don't it will most likely just crash.
I am working on a tool to produce map images for a large number of 2d RTS games. It will use pud2bmp code for the War2 map module. In the meantime you might consider PudBrowse - a similar tool that produces tactical minimaps of PUDs.
Sample image maps/Classic/Expansion/Atols.pud - click for full size:
Greg Kennedy 2007 (contact)