Also available:Doom 2 Minor Sprite Fixing Project - v1.8 Release (updated 11/15/16)
Greetings, Doomworld forums! To cut straight to the chase, I'd like to present the Heretic Minor Sprite Fixing and Widescreen-Friendly Project, created in much the same fashion as my Doom 2 project.

The three main goals of this endeavor are as follows:
1. Adjusting sprite offsets - This comprises the bulk of the project. This is meant to provide smoother and more consistent visuals during animations, when switching between different states, and between rotations. Additionally, some sprite offsets were shifted slightly upwards to avoid the sunken underground look.
2. Small image edits - There are a number of trivial errors found in Heretic's sprites. These mainly consist of transparent pixels or visible garbage pixels that were overlooked. If I could conclusively identify the issue as being an error and the fix would be as minimally intrusive as possible, I went ahead and made the edit to the sprite.
3. Making the graphics widescreen-friendly - For those running source ports with widescreen resolutions, you've likely noticed that some sprites cut off abruptly near the sides of the screen as they were only intended to be seen in a 4:3 aspect ratio. This pack extends these sprites so you can enjoy all of that extra viewing area without impediment. Credit goes to one Neoworm for creating most of these new graphics.

As for how to use it, this WAD in its current state works with limit-removing ports. However, vanilla heretic.exe compatibility simply requires some DeuSF work. With that in mind, you can pretty much use this WAD with any other level or mod as I can't imagine any conflicts. Simply run it with the lowest priority in the add-on hierarchy. Most newer source ports have an autoload feature, so I recommend using that.

Here's the current download of v1.0 (released 7/5/13):
http://www.mediafire.com/download/lbous134qm7zwib/HRSPFX10.rar (669.97 kb)

The complete changelog can be viewed here:
https://drive.google.com/file/d/0B4X6_GM5D7D_M21NUm1jZTZYblk/view?usp=sharing

Note: The sprite fixes and widescreen-friendly graphics are split into two WAD files. This is meant to provide compatibility with the original Heretic executable as the widescreen graphics will cause the engine to crash. Anyone using source ports (most everyone, I'd imagine) should load both WAD files at the same time.

Sample of some of the fixes:

(clickable thumbnail)
(clickable thumbnail)

This project is still very much a work-in-progress. I'm open to feedback on the current release as well as potential ideas for further changes.