IrfanView

[HDiddy]

If you ar looking for a good program to do batch changes on images...like change all your pose icons to 64x64 this one works well

https://www.irfanview.com/

[TTomBBlack]

XnViewMP is also a good tool. I already use it for years

[MarkZappa]

Didn't knew IrfanView had that functionality, I never tried it... for batch processing I use my old copy of Adobe Photoshop CS3 with Adobe Bridge CS3 and batch processing built in plugins

[x17]

Yep, I used both Irfanview in past, and now XnView (which I find even better a bit) - probably some of best image viewers.

Plus, I use SageThumbs addition.

[RyfeFur]

Echoing other posters, I think Irfan has largely been supplanted by XNView (though I've had some problems with some versions of the MP version)

[state808]

I use IRFAN for all my batching and it's really great at renaming. If you look in help, there are a LOT of options for renaming! Plus, you can output to specific pixel width, filesize...just so much flexibility!!! Highly reccommend!

[nogimist]

Irfan View is easy of handling and still under development. For png-Files perfectly more simply than XNView, i think.