(sorry if this is a repeat of any previous thread)
I use Jasc Paint Shop Pro Studio version 1.01. Most of my images are appearing grainier than I'd expect when I save to jpg. I use a compression factor of 1.. the lowest available. Then there's these options called Standard, Progressive, and Lossless encoding. I have no idea what those do so I've been using standard. What am I doing wrong? Do I even have to use jpgs here?

I'm not sure about Jasc, but the programs I use have a scale for compression where high numbers mean high quality (low compression). To see if it is the lossy compression that is the problem, you should save the image in a lossless format (like PNG) and compage the two images.

Great! That works. Can I upload png files here?

Yes, but only if they meet the fielsize limits and even then they are converted to jpg. It's better to just use JPG.

Paint Shop Pro 9 has a feature to improve grainy images, it works pretty good (although of course it can't produce perfect grainless images) - maybe your version has the same, then you could give it a try?

I had the same suspicion as caedes, that higher is better. But I found from this page (LINK) that the scales are different between JASC and Adobe. "...save my images at the highest quality level. In Jasc Paint Shop Pro, that's a quality level of 1. Make sure to double-check your photo editor to make sure you're using the highest level. In Adobe Photoshop Elements, for example, the scale works differently: The best quality is actually 12."

So at a JPEG compression of 1, you should really find the image pretty much indistinguishable from an uncompressed TIFF. The only thing I can think of at the moment is that it's a small-sized file that you're viewing at more than full-size. If you are zoomed on an image at more than 100% you're going to start seeing the pixels and things will look blocky on screen (while not affecting the actual file). And actually, depending on the viewing software, viewing at 66% or 33% results in artifacting on screen as well. I know photoshop does this, it's nearly impossible to edit a photo at 33 or 66% view ratio. Details get screwed up because it's trying to fit 3 pixels in the space of 2 on screen.

You can also run a grainy jpeg through Neat Image which you can download a free version of and it usually does a pretty good job of eliminating the graininess.

From my experience Neat Image does little more than blur the picture, but I am no pro. Maybe try using a different program to switch from png to jpeg.