Image Scaling On A Fixed Pixel Display

[iignotus]

When you say the psp is better than the gp32 playing genesis

I never said any such thing. I never even mentioned the GP32, and all I said was that the PSP has a nicer screen, not a better one for emulating. Totally different.

You mean it would only take up part of the screen, right? Isn't that what he's talking about though?

It would only take up part of the screen on a GP2X, as well. They both need scaling.

Bigger dosent mean better

Then why are we talking about scaling? :blink: :blink:

I mean guys, if you don't understand and need me to go over this in more detail, please say so and I'll be glad to do so. But I thought I was making it as clear as possible.

Edit -- the link in my signature should be working now. Thank you, Deleted User -- telling me that really helps a lot.

 

[DaveC]

DaveC said that the GP2X's display is perfect. Well it is and it isn't. It's a better ratio than the PSP's; it's more accurate. However, you STILL HAVE TO SCALE. And this is just for Genesis.

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First I have never played a MD rom that is only 192 high. They are all 220 high, some are 320 wide others are 256 wide.

You do not have to scale I don't know why you keep saying that. The image on the 320 x 240 screen is close enough and large enough that you do NOT need to scale that is the point. Yes if you want to use every single pixel and have NO black bars anywhere then you would need to scale. But what I am saying is that the image fills so much of the screen that the image is large enough that scaling is not really needed. With other devices that have smaller pixels the image is getting so small and makes scaling almost required.

The GP32/GP2X screen size and resolution is just *better suited* for unscaled images than the others that is all.

 

[Hanz™]

DaveC said that the GP2X's display is perfect. Well it is and it isn't. It's a better ratio than the PSP's; it's more accurate. However, you STILL HAVE TO SCALE. And this is just for Genesis.

you do a bit less scaling on the GP2X.

You said it yourself.

 

[deadlychicken22]

It would only take up part of the screen on a GP2X, as well. They both need scaling.

But wouldn't it be physically bigger on the gp2x even at the same resolution?

 

[DaveC]

Ignotus, clearly some screens are better for some systems, but the vast majority of 16 bit consoles and pre-them era use roughly 320x240, hence why its a good one. Genesis pans out, Snes too, Amiga, ST, PCE, Master System, NES... quite a few.

NES doesn't, PC Engine doesn't, Atari ST doesn't. Master system sometimes does, sometimes doesn't. And I'm not sure which Amiga computer you're talking about emulating.

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He said ROUGHLY 320 x 240 not EXACTLY 320 x 240.

Most of those are large enough to where it is better left at 1:1 as the size difference you would get if scaled is not worth the artifacts.

 

[DaveC]

It would only take up part of the screen on a GP2X, as well. They both need scaling.

But wouldn't it be physically bigger on the gp2x even at the same resolution?

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Yes that was the point.

 

[iignotus]

You said it yourself.

You are kidding, right?? Don't overlook information in this post just for an attempt to discredit what I'm saying. DaveC said, and I quote, in the first post, "It also explains why the 320 x 240 screen on the GP32/GP2X is pretty much ideal for emulation.". I didn't say that the GP2X's display was perfect, since I said it has to do scaling as well to fit the entire screen.

First I have never played a MD rom that is only 192 high. They are all 220 high, some are 320 wide others are 256 wide.

Than that's an even stranger ratio, not even close to 4:3. Also, I've never seen anywhere where the image is 220 high. Please point to documentatoin or examples saying so.

I see now that this is basically about physical image size, on the device. You're not worried about whether or not you have to do scaling, just how much you have to do to fit on the screen.

Guys, there are lots of different factors that go into something as 'simple' as scaling a moving image from one device to fit another. Some of you are disregarding the many options that are available in this situation as well.

DaveC is right in one way, that the GP2X's screen is visually, physically, better suited for emulating a console such as the Genesis than the PSP is, because the image on the GP2X is bigger without scaling than it is on the PSP. BUT ALL THIS HAS TO DO WITH IS PIXEL PITCH. NOT RESOLUTION. You still have to scale to fit the GP2X's full screen size. It's just that if you don't, you get a larger image than you do if you don't scale with the PSP.

 

[DaveC]

...

But see, this 256x192 resolution will display PERFECTLY on a PSP screen. It will look absolutely wonderful. 256 fits into 480, and 192 fits into 272. You'll have a perfect render of the screen. You'll see lots of black nothing around the image, but the game will look perfect. However, since the PSP's screen pitch is smaller than the GP2X's, the actual, physical image you see will be smaller on a PSP than on a GP2X, since the GP2X has a smaller resolution.

And also like I said, very many consoles don't have a 4:3 display ratio, and NONE of them have a 320x240 resolution that I can think of off the top of my head.

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It dispays perfectly on a PSP screen only smaller than it displays on a GP32 screen UNSCALED.

None have EXACTLY 320 x 240 res but the point here is that again it matches *close enough* to where you don't really NEED the stretching to get a decent sized image like you do on smaller pixel devices.

 

[iignotus]

He said ROUGHLY 320 x 240 not EXACTLY 320 x 240.

I was talking about ratio, not resolution. Generally, they will fit on a 320x240 screen and don't need scaling, though -- but they're not even the same ratio as 320x240 is (4:3).

Most of those are large enough to where it is better left at 1:1 as the size difference you would get if scaled is not worth the artifacts.

You are completely, absolutely, 100% correct there. But this whole topic was about scaling, I thought.

None have EXACTLY 320 x 240 res but the point here is that again it matches *close enough* to where you don't really NEED the stretching to get a decent sized image like you do on smaller pixel devices.

Then you should have labeled this topic something like "Comparing pixel sizes on displays". The entire topic seemed to be about scaling, which you now say you don't even want to do on a GPX2's screen because it's good enough.

 

[DaveC]

First I have never played a MD rom that is only 192 high. They are all 220 high, some are 320 wide others are 256 wide.

Than that's an even stranger ratio, not even close to 4:3. Also, I've never seen anywhere where the image is 220 high. Please point to documentatoin or examples saying so.

.... It's just that if you don't, you get a larger image than you do if you don't scale with the PSP.

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Documentation? Don't have it BUT I play DrMD all of the time and all games always fit vertically the same at 220 lines. There are never cases where there are wider bars on the top or the bottom. There are a few cases where there are bars on the SIDES but that is it (256 wide instead of 320).

"It's just that if you don't, you get a larger image than you do if you don't scale with the PSP."

That was kind of the point. Except it wasn't really directed at the PSP, just devices with finer pitch higher res displays. The Zodiac is even worse than the PSP for image size at 1:1.

 

[DaveC]

First I have never played a MD rom that is only 192 high. They are all 220 high, some are 320 wide others are 256 wide.

Than that's an even stranger ratio, not even close to 4:3. Also, I've never seen anywhere where the image is 220 high. Please point to documentatoin or examples saying so.

​

Well you have to remember these consoles were designed for CRTs. With a CRT you can alter the pixel size a bit through the TVs scan rate. A Genesis at 4:3 but 256 wide res would have rectangular pixels. When a Genesis was in 320 wide mode the pixels were more square. It was always 4:3 though. When displaying on an LCD the pixels are ALWAYS square so then the aspect ratio on the LCD changes a bit.

This is aspect ratio related, I wasn't even talking about that at all, that is another topic.

 

[deadlychicken22]

Then you should have labeled this topic something like "Comparing pixel sizes on displays". The entire topic seemed to be about scaling, which you now say you don't even want to do on a GPX2's screen because it's good enough.

Actually, I think the topic was started to help people understand what DaveC's telling people everytime they mention the gp2x's resolution. Is there something wrong with the conversation covering a topic that is related to the main topic?

 

[iignotus]

That was kind of the point. Except it wasn't really directed at the PSP, just devices with finer pitch higher res displays. The Zodiac is even worse than the PSP for image size at 1:1.

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I just used the PSP as an example, since you mentioned it and it's very popular at the moment.

Well you have to remember these consoles were designed for CRTs. With a CRT you can alter the pixel size a bit through the TVs scan rate. A Genesis at 4:3 but 256 wide res would have rectangular pixels. When a Genesis was in 320 wide mode the pixels were more square. It was always 4:3 though. When displaying on an LCD the pixels are ALWAYS square so then the aspect ratio on the LCD changes a bit.

This is aspect ratio related, I wasn't even talking about that at all, that is another topic.

That's pixel ratio, not (image) aspect ratio. I never even got into square or rectangular pixels, being that it doesn't really even matter.

 

[iignotus]

Then you should have labeled this topic something like "Comparing pixel sizes on displays". The entire topic seemed to be about scaling, which you now say you don't even want to do on a GPX2's screen because it's good enough.

Actually, I think the topic was started to help people understand what DaveC's telling people everytime they mention the gp2x's resolution. Is there something wrong with the conversation covering a topic that is related to the maint topic?

​

Not at all. Should there be? I just saw this topic about scaling, not pixel pitch. Maybe I didn't see the posts correct intention and therefore went off topic a bit, but everything I said was correct.

 

[deadlychicken22]

Then you should have labeled this topic something like "Comparing pixel sizes on displays". The entire topic seemed to be about scaling, which you now say you don't even want to do on a GPX2's screen because it's good enough.

Actually, I think the topic was started to help people understand what DaveC's telling people everytime they mention the gp2x's resolution. Is there something wrong with the conversation covering a topic that is related to the maint topic?

​

Not at all. Should there be? I just saw this topic about scaling, not pixel pitch. Maybe I didn't see the posts correct intention and therefore went off topic a bit, but everything I said was correct.

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Well, it sounds like you know what you're talking about to me, but then why is there an argument? If you know what you're talking about then surely you think the gp2x's screen is better than the psp's because it can play older systems without scaling (or whatever the technical term is) and not be the size of a postage stamp? Maybe I just don't understand..... I'm still buying the gp2x though.

 

[iignotus]

Well, it sounds like you know what you're talking about to me, but then why is there an argument? If you know what you're talking about then surely you think the gp2x's screen is better than the psp's because it can play older systems without scaling (or whatever the technical term is) and not be the size of a postage stamp? Maybe I just don't understand..... I'm still buying the gp2x though.

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Well thank you. And honestly, what some people see as arguing, I just see as discussing. There is a fine line, usually the introduction of profanity, but I thought I was just trying to put in more info and correct a few things. I was the captain of my debate team in high school, and I'm just used to using sharp comments sometimes to make my point. Sorry if it sounded like an argument, or if anyone thought I was trying to start one.

And of course, I do think that the GP2X's screen is better than the PSP's for emulation. But I also thought that DaveC said the reason why it's better was because you didn't need scaling like you do to get a full-screen image as you do on the PSP, as that's what his posts looked like. The fact is that you have to scale on both system's screens to get a full-screen image, but that the image without scaling is better on the GP2X. I didn't infer that he was talking about NOT scaling the image (and pixel size).

And I've been pre-ordered for the GP2X for 3 weeks now, and I have no intention of ever getting a PSP.

 

[deadlychicken22]

Ok, nice to see we agree on that.

 

[starpause]

old saying--you can be happy, or you can be right. it seems like there was a lot of miscommunication in this thread ... at least partially due to people protecting their egos! i won't bother re-hashing the points as it seems an understanding has been reached

i already had the ides on scaling, pixel pitches, etc ... did a lot of 2d graphics work in my college program, but i think this thread is a good read if you can sort the facts out from the bickering :rolleyes:

more information can be found in wikipedia's article on pixels ... the best part is, you can add any thing you don't see covered (i.e. scaling is only sort of covered in (Native vs. logical pixels)

 

[DaveC]

And of course, I do think that the GP2X's screen is better than the PSP's for emulation. But I also thought that DaveC said the reason why it's better was because you didn't need scaling like you do to get a full-screen image as you do on the PSP, as that's what his posts looked like.

There was the confusion. I never meant that you could get *full screen* without scaling/stretching.

My point was if the image was displayed at 1:1 WITHOUT scaling that it would be larger and fill the screen better on the GP2X than other higher resolution devices. That is about it

 

[iignotus]

Aw yay. See how nice it is now that we all know what we're talking about! :lol:
::hugs::