Subject: Re: [stella] NTSC - PAL porting guide From: Glenn Saunders <krishna@xxxxxxxxxxxx> Date: Sat, 8 Mar 1997 12:42:59 -0800 (PST) |
On Sat, 8 Mar 1997, Eckhard Stolberg wrote: > NTSC PAL > > grey grey It would be useful to establish actual RGB values for 2600 output instead of just names. I realize that these are the 16 hue values available. You won't be able to establish true RGB values just by grabbing screens because the 2600 may be slightly off its center calibration and going from RF or composite to RGB results in unpredictable results. But it could be calculated mathematically. If you establish that there are 16 hues, and 8 luminances per hue, then you should be able to convert HSV to RGB to get at the internal values the 2600 is attempting to generate. I could probably do it if noone else wanted to. This is probably what emulator authors did, which also results in unique problems when you run these RGB values on a computer monitor, which has much different visual characteristics to NTSC monitors. RGB is almost always darker with less color saturation. NTSC composite has "compressed" bandwidth. The look of 2600 graphics is in part due to the characteristics of NTSC (or PAL I guess) video. Authors should write with this in mind. So there is an "internal" RGB value, and then a conversion for the apparent RGB when viewed on a TV. It differs from monitor to monitor, which is why we have to start out at least by using the internal values, and then average out some kind of conversion table for "apparent" RGB values. > orange gold > orange green grey > light orange grey What seems odd about this is that the 16 hues on the left table do not match up with the right table. There seem to be more hues available in NTSC... For instance, there are no orangy hues in PAL, as these tend to come out "grey". Shouldn't the 2600 be able to generate all the same hues in PAL as it can on NTSC? -- To unsubscribe, send the word UNSUBSCRIBE in the body of a message to stella-request@xxxxxxxxxxx
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
[stella] NTSC - PAL porting guide, Eckhard Stolberg | Thread | Re: [stella] NTSC - PAL porting gui, Nick S Bensema |
[stella] Crackers' Easy Playfield G, crackers | Date | Re: [stella] Two triple-copy sprite, Greg Troutman |
Month |