What I've been seeing is that much of the data is stored in fixed record format, usually with all of them listed one right after the other.  Teams and Players were like that and I'm betting that the complete image list is stored the same way.  Just need to figure out that format.

What sometimes makes this a bit trickier is that the images you currently have are the PC version, but are not identical.  For example, I appear to have found the equivalent of CHEER501.WMS in the arcade data file, but the PC version does not have the title of 'The Cheerleaders' where the arcade version does.

I'm still working on the conversion of the image format to 32-bit RGBA.  I thought I had it correct, but when I output one of the images, it's wrong.  I'm trying to find a good reference image that is the same in the arcade as it is in PC game.   

Yes, one of the values is mipmap level.  It's the 7th uin32.  The values are 0 (no mipmapping), 2, 4, 8. 

8 is what you will see in all of the LOD (level of details) images used for the uniforms (like CHIHLOD.WMS) or the banner page (BANPAGE.WMS).

The Ads only use 2 levels (ADS_D.WMS).

Looking at all the actual images, this makes sense.

I also found another file format: 0x0b == RGBA1555.  Basically colors are 5 bit channels, and alpha is 1 bit.

Based on the info you gave me, here's what I was able to figure out:
It is a 40 byte header.  I actually believe it's a 10 uint32 header.  Based on that, this is what I believe is the record format of an image:

Position	Purpose
0	?? - File Type? Always set to 0x8005 to indicate it's an image?
4	?? - Unknown Value
8	?? - Unknown Value
12	?? - Unknown Value
16	Width of image
20	Height of image
24	?? - Unknown Value
28	?? - Unknown Value
32	?? - Unknown Value
36	The pixel format used in this image
40	The actual pixel data as an array of int16 (`Width` * `Height` * 2)

I have the data file reader processing a RGBA4444 format into a class called Image.  Each pixel in the data is converted from uint16 to ImagePixel class that contains Red, Green, Blue, Alpha properties.  That was simple since and just need to do RGBA565 next.  I'll output some of these as PNG just so I can confirm they are correct.  Honestly, I don't think I'm keeping ImagePixel as it's a waste of space since we're not doing direct image manipulation and uint32 works just as well. 

The other thing I noticed is that all images are 256 pixels wide and the images basically wrap.  I'm sure one of those values in the header describes the wrapping, but haven't really analyzed multiple records yet.

Blah,

I literally had a whole bunch of info typed up then my session timed out... Going to get some things put in word, then out on git (code you have out there now looks great, btw!).

But pretty much, here is some quick info on the image formats used in blitz (the ones I know of).

The Images are the same images used in the NFL Blitz PC versions (99 ans 2000).

Here are the PC images:
http://www.mediafire.com/file/wzgreo0am0kvbyt/data.7z/file

The headers are 41 bytes from what I can tell.
There are 2 images formats:
RGB565
RGBA4444

offset 36 (decimal) tells you what image type the file is:
        rgb565 = 0x0A,
        rgba4444 = 0x0C

My idea was to make a console app to look up each image file in the arcade raw drive and record its offset. Open to better ideas though.

Hey jaker,

My physical copy of NFL Blitz PC came today so I'm all set. I'll try to get a copy of NFL Blitz 2000 for PC someday too. Good luck with your work, I can't wait to give the PC version some roster updates like we've given the N64 version Have you thought about expanding the file editor to work with PC files? Custom textures on PC would be a cool next step to look into for PC Blitz hacking.