image quality

I am looking for some basic information about image quality in point and shoots. What really determines image quality? I digiscope and currently use a Canon SD1200 IS but know the camera at $150 or so is entry level. I am looking at the S90 which is one nice looking camera with all of the features.

In the picture itself....what really determines quality? Is it the size of the sensor, the pixels or ? Please enlighten me.

I have a feeling that my pictures would improve by getting the S90 but it is $'s... You info is appreciated? Thanks, jim

What determines image quality? The answer is "Yes".

There's no single element of a camera we can point to and say "That is responsible for getting good image quality." The bigger the sensor is for any given MP count, the more it'll resist noise. The sensor with fewer pixels for any given sensor size will also have less noise than a more densely packed sensor. And without a good lens you won't get a good image; lenses with smaller zoom ranges are easier to design, so the smaller the zoom range the better. The processor (Canon's currently using their DiGiC 4 processor) makes a difference as well. So there are a lot of things that contribute to making the best IQ. Pretty much everything that goes into the making of the camera, in fact.