Cspyro:
The trick to resizing - for me; anyway - is to make the initial shots as large as possible. If you can; whichever program you're using; set it to record screenshots in .bmp mode; not jpeg. That means there's no compression; you're dealing with the raw image.
That way; if you have to crop or otherwise adjust the pics size; you can do so before compressing it to below 100K.
As an example; assume I take a quick pic. It's huge; several Mb. I use MS Paint to crop the image to where I want it; make it look good. THEN I open Pix Resizer and convert it into 800X600; 100Kb. max.
Do it that way; you'll get good clear pics every time.
Of course; there's probably an easier way.
Hope this helps!
