Converting in background selected file to JPG format (you can change extension to gif/jp2 (or another else served by irfanview - remember - you maybe need plugin for this format installed in irfanview)):
Nope, no sarcasm here... plain or otherwise. Just explaining my reasoning for asking the question... very simply:
I see buttons posted using a third party app doing something Opus can do built-in without third party app
I wonder "hmmm... has this person found that IrfanView does a better job than Opus in some cases"
This person points out that Opus doesn't support other formats... great reason to go to an external app
This person get's on my case for explaining myself...
Now that was ~slightly~ sarcastic
And no need for me to post any buttons for other users... I ~think~ Nudel's Images toolbar has the basics for doing the same things using internal Opus functions.
Sorry you took "questions and comments" as sarcasm... unintentional.
I think I understand the primary thing LITWINCZUK was saying steje, as I used IrfanView for awhile and it does support a vast array of command line parameters. For general re-sizing and conversion Opus does fine with images but if you want to go far beyond that while seemingly staying within Opus, you could build IrfanView buttons that run in hide mode.
These days if I want to do more than basic re-sizing, I use the Photoshop but I can see the potential value of using IrfanView command line options.