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PostPosted: Sun Oct 16, 2011 3:34 pm 
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beannaich wrote:
ask and ye shall receive


The colors are inverted. Funny. :)

Plus, the background color of SMB1. Should it be purple or blue? We get a blue with HUE +1 (30 degrees), but other colors (like Mario colors) become purple-ished.


Last edited by Zepper on Mon Oct 17, 2011 8:14 am, edited 3 times in total.

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PostPosted: Sun Oct 16, 2011 5:23 pm 
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nice job! I tried this with my emulator (increased the saturation a bit), and it looks great!

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PostPosted: Sun Oct 16, 2011 6:25 pm 
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Zepper wrote:
The colors are inverted. Funny. :)

Inverted? Weird. I suggest you just generate one for yourself then, seeing how it's not hard to port to any language.


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PostPosted: Sun Oct 16, 2011 7:26 pm 
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beannaich wrote:
Zepper wrote:
The colors are inverted. Funny. :)

Inverted? Weird. I suggest you just generate one for yourself then, seeing how it's not hard to port to any language.


Yup, I had to do a XOR $FF to fix the palette.

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PostPosted: Mon Oct 17, 2011 3:46 am 
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Haha, I must have generated your palette while I was making my "negative" palette!

sorry zepper


Last edited by beannaich on Mon Oct 17, 2011 8:57 am, edited 1 time in total.

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PostPosted: Mon Oct 17, 2011 8:14 am 
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No problem. :)

Back to my question...

Quote:
Plus, the background color of SMB1. Should it be purple or blue? We get a blue with HUE +1 (30 degrees), but other colors (like Mario colors) become purple-ished.

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PostPosted: Mon Oct 17, 2011 8:51 am 
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Quote:
Plus, the background color of SMB1. Should it be purple or blue? We get a blue with HUE +1 (30 degrees), but other colors (like Mario colors) become purple-ished.


As far as I can remember, the background was slightly purple on my tube television back in the early 90's. Of course, that answer is stooped in subjectivity, and different televisions with different settings would produce different results. But it's not at all out of the ordinary for SMB's background to be a light-tone blue-purple mix, while all the other colors look "normal".

Hope that helps answer your question.

edit: here is what it looks like running on nintemulator


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PostPosted: Wed Oct 19, 2011 5:31 am 
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Bisqwit: http://bisqwit.iki.fi/utils/nespalette.php -- create and download tailor made NTSC palette with this tool.


Can you make standalone-generator, please?


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PostPosted: Wed Oct 19, 2011 5:33 am 
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Eugene.S wrote:
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Bisqwit: http://bisqwit.iki.fi/utils/nespalette.php -- create and download tailor made NTSC palette with this tool.

Can you make standalone-generator, please?

I think mr. beannaich made one in Java, I presume it could be used as a standalone program. beannaich?


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PostPosted: Wed Oct 19, 2011 7:05 pm 
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The NES palette has always interested me. I wrote an NES program that shows all 64 colors and then ran it (powerpak) on the consoles I own (pal, ntsc, famicom av). I captured the result to PC with my philips video card and then used another program I created to get a 192 byte pal-file from the captured image.

Finding a video capture setting (hue, brightness, etc) that matched what my pal-tv displayed and looked good to me was the hardest part, but I think I eventually found some pretty good settings and nice looking palettes.

Here are captured screens with my nes palette viewer running on NTSC and PAL consoles. Famicom is very close to NTSC (obviously) so it's not shown.

NTSC:
Image

PAL:
Image


Even though I liked the palettes created from this I've always felt that this is something like a "hack" and generating the palette in code is a much better way. The problem is that I've tried many different palette generators and never really liked the result. Mostly because they don't match my captured palettes very good. Perhaps I just couldn't find the right settings? Other strange thing is that the default setting in palette generators produce something more like my captured PAL-palette even though they are supposed to be NTSC-generators?

So I'm wondering if you Bisqwit or someone else can tell me what settings I should use in a palette generator to match my captured palettes (PAL and NTSC)?

And is Bisqwit's generator closest to the "real thing"? I was under the impression that not enough is known about exactly how the PPU generates colors to correctly emulate it?

And if anyone is interested I've uploaded the nes palette viewer rom and program I mentioned above (use at own risk). Also included are the pal-files if someone wants to try them in emulators.
http://www.mediafire.com/?9rniim958a31eys


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PostPosted: Wed Oct 19, 2011 7:44 pm 
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That problem with that approach is that you're at the mercy of how your video capture device encodes the colors.

edit: Palette version: (NTSC)
Image

And PAL:
Image


Edit:
It's not my palette, it's Kinopio's.
I took the pictures of Kinopio's palette, and turned it into solid colors with palette attached. The original image did not have solid colors, you'll notice that there are striped patterns and stuff like that in there, almost as if it was saved as a JPEG first. So I took the average of the inside of the squares by using a mosaic filter in Photoimpact.

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Last edited by Dwedit on Fri Oct 21, 2011 11:16 am, edited 4 times in total.

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PostPosted: Wed Oct 19, 2011 7:53 pm 
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Kinopio wrote:
I was under the impression that not enough is known about exactly how the PPU generates colors to correctly emulate it?
We know exactly how the PPU generates color. The problem is that every television parses the output slightly differently, and so there isn't one correct palette.

(For example: US NTSC has a black level at 7 IRE that's not the same as not-sync (0 IRE), making the NES's colors more saturated and darker than the Famicom's. Televisions that implement proper YIQ decoding will blur some colors more than those that just do YUV decoding. And some televisions actually distort the colorspace transform to RGB to "enhance skin tones", whatever that means to the NES)


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PostPosted: Wed Oct 19, 2011 8:06 pm 
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I recall kevtris mentioning that the video signal as seen by his scope wasn't a straight square wave, because of the video filtering in the system already. He mentioned it looking like a somewhat distorted, slightly lopsided sin wave.


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PostPosted: Wed Oct 19, 2011 10:54 pm 
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Bisqwit wrote:
Reading the NTSC encoder page at http://wiki.nesdev.com/w/index.php/NTSC_video , I decided to create my own palette synthesizer based on the description. I first looked upon Blargg's nes_ntsc, but it seems to use a sinewave rather than the described squarewave for the color synthesis.

Not entirely true. Of course, the PPU produces a square subcarrier of color. But between the PPU and the decoder has a lot of electronics and transformations. Even if you omit the RF channel, suggesting a connection via AV, is present even here a couple of stages of amplifiers or repeaters (the two-stage repeater are directly connected to the PPU video output). These circuits have limited bandwidth, so the square wave (which theoretically requires infinitely high frequency) can be integrated into almost a triangle. I see this on an oscilloscope even on AV output. Something like this:
Image
So, we have some additional phase shift, which is critical for PAL/NTSC systems. And this shift is slightly distorts the resulting color. Here the video (yellow) and the signal F2 (blue):
Image
If you increase the color burst, you can see that it is not rectangular, as expected.
Image
Your move. :3


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PostPosted: Thu Oct 20, 2011 12:21 am 
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In theory, the phase shift should cancel out. Yes, the colorburst is shifted, but the color is determined by the phase relationship between the colorburst and the mid-line chroma signal, which should be hit with the same phase shift.


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