I'm having a bit of a problem understand how much memory images use in gamestudio. I have some 800x600 pcx images i'm using for some pannels , and even though the file size is only around 360k , when i make the panel visible ingame the bmp emory usage jumps from 500k to 2450k , how can an image thats only 360k in size take up around 2MB of memory? If anyone can better explain to me why this is I would really appreciate it.

800x600 means 480,000 pixels. At 24-bit color, that's 1,440,000 bytes of memory needed for it. If 32-bit color (I don't know if PCX supports it (nor do I know it's format), but given the 500K to 2450 KB jump you have, I suspect it does), it's 1,920,000 bytes.

so what counts is the resolution rather than the file size itself , would a lower resolution panel image scaled up to fit the screen consume less memory ?

Resolution shouldn't have anything to do with it. Resolution would indeed affect video memory usage overall, but it wouldn't affect the video memory usage of a panel. What affects the video memory usage of a panel is actually the size of it. Unless DDS is used for texture compression (I don't know if panels support it), the image is loaded into video memory as if it was fully expanded and uncompressed.