Edit: These instructions are now dated, but please follow the link below for the latest version and instructions.
Here's a quick and dirty tool to view sprites stored in Sega's System 16 format. I searched for something similar, but couldn't find anything, so coded my own.
To use the tool, you will need to place the appropriate sprite files in the roms subdirectory.
The easiest way to determine which rom filenames you require, is to look at the relevant MAME driver file. Here are some links:
Find the section where the sprites are loaded. You must load the files in blocks of four. Some games have multiple banks of sprites. Here's an example for OutRun:
For example, in this case, to load the first batch of sprites you would run the tool as follows:
s16GfxViewer mpr-10371.9 mpr-10373.10 mpr-10375.11 mpr-10377.12
And for the second sprite bank:
s16GfxViewer mpr-10372.13 mpr-10374.14 mpr-10376.15 mpr-10378.16
One thing to note is that the sprite data does not contain palette information. By default the tool displays the files using a pseudo-greyscale palette.
However, for OutRun I've extracted the sprite palettes from the 68000 program files. And you can toggle through all 255 palettes by using cursor left and cursor right. Unfortunately, there is no automatic way of determining which palette goes with which sprite. This information is hardcoded by the game at runtime. Some sprites can use more than one palette.
One cool use for this tool will be to search for unused graphics in Sega titles. Please comment below and post a screenshot if you find any. For example, here is an unused start banner from OutRun that is revealed by palette switching (using palettes 41 and 42):
I will be posting the source code to this tool when I release the Cannonball source code before the end of the year. Maybe someone wants to have a go at locating and including the other palettes.
Page Up/Page Down: Scroll Page
Cursor Up/Cursor Down: Fine Scroll
Cursor Left/Cursor Right: Change Palette (OutRun palettes only)
Space: Save a BMP