Probably every programmer on this world has his image collection to use in toolbars. It is usually collected over years and gets reused quite a lot. I have collection of my own and it seemed like a natural solution to use it in WPF also.
As I am big fan of high DPI setting and I got used to expect little bit of blurriness in my toolbar as unfortunate result of scaling bitmap from 16x16 (at 96 DPI) to 20x20 (at 120 DPI). However, nothing could prepare me for amount of blur that WPF brought.
Quick search discovered a clue and look on my system confirmed it. Almost all images I had were 72 DPI. That meant WPF did scaling even on systems with "normal" DPI settings.
Scott gave easy fix in form of PNGOUT tool. I tried it out and checked results in Paint.NET. Unfortunately, instead of promised 96 DPI, I got 120 DPI images. Issue here is that PNGOUT uses DPI settings as defined on system. High-DPI setting on my system meant that PNGOUT will not work correctly without configuration change (and required logoff/logon).
Quite annoyed I made quick program in C# that just loads whatever image you give it on command line (e.g. "dpi96.exe *.png") and changes it's DPI setting. This finally worked as promised. This small utility is available for your use also.
P.S. Yes, I know that I should prepare separate bitmaps for all common DPI settings. I am lazy and artistically-challenged.
P.P.S. This utility was made in less than 10 minutes. Do not expect extra-quality code (or any exception handling).