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What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340200] Sat, 25 March 2017 09:51 Go to next message
Lukazi is currently offline  Lukazi
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Hi All,

I've spent the last few months trying to see what Double High Resolution Graphics (DHGR) is really capable of. It's a work in progress but the results look promising.

http://lukazi.blogspot.com.au/2017/03/double-high-resolution -graphics-dhgr.html

Cheers,


Alex.
Re: What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340201 is a reply to message #340200] Sat, 25 March 2017 10:02 Go to previous messageGo to next message
Bill Buckels is currently offline  Bill Buckels
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"Lukazi" <lukazi@hotmail.com> wrote:
> I've spent the last few months trying to see what Double High Resolution
> Graphics (DHGR) is really capable of.

When you find-out let me know... so far yours are roughly equal to what
Sheldon Simms, Blurry, and I have produced. Good article too...

The DHGR converters that we have today produce infinetly superior results
than anything historically produced in the 80's and 90's that I am aware of.

Bill
What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340202 is a reply to message #340200] Sat, 25 March 2017 10:02 Go to previous messageGo to next message
zellyn is currently offline  zellyn
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Reading now... Looks fantastic so far.

FWIW, OpenEmulator actually emulates NTSC color processing (using GPU shader code) so you might want to look at that...

Zellyn
Re: What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340203 is a reply to message #340200] Sat, 25 March 2017 10:38 Go to previous messageGo to next message
Anonymous
Karma:
Originally posted by: Nicola

On 25/03/2017 14:51, Lukazi wrote:
> Hi All,
>
> I've spent the last few months trying to see what Double High
> Resolution Graphics (DHGR) is really capable of. It's a work in
> progress but the results look promising.
>
> http://lukazi.blogspot.com.au/2017/03/double-high-resolution -graphics-dhgr.html

I am really impressed by what you guys are doing with Apple ][ graphics
(you, B. Buckels, and all the other people already mentioned).

I wonder if anyone has thought of combining such good images with a good
plot for a text&graphics adventure game.

Nicola
What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340204 is a reply to message #340202] Sat, 25 March 2017 11:03 Go to previous messageGo to next message
zellyn is currently offline  zellyn
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Registered: April 2013
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A couple of further thoughts after reading the whole thing.

1. If you have a Mac, definitely give 4am's OpenEmulator build a try: I think you'll be astonished at just how good the NTSC emulation is: choose the color monitor with all the settings, and you can tweak away until it matches what you're seeing on your actual CRT. You need 4am's build because my IIe changes are still in progress...

2. I have been thinking of porting the OpenEmulator NTSC emulation to a standalone library, to a web GL shader, and to non-gpu normal Go code. Sounds like I should get busy!

3. I've been wondering about the idea of dithering and DHGR as a maximization problem: use the NTSC emulation to render; then score the difference from the rendered image using a weighted combination of gaussian blurs of different radii, and possibly some edge detectors; then just randomly toggle bits and accept changes that improve the score. If anyone here understood this paragraph and has ideas, thoughts, suggestions, or pointers to literature, let me know :-)

Zellyn
Re: What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340216 is a reply to message #340203] Sat, 25 March 2017 13:29 Go to previous messageGo to next message
Anonymous
Karma:
Originally posted by: Mark D. Overholser

On 3/25/2017 07:38, Nicola wrote:
> On 25/03/2017 14:51, Lukazi wrote:
>> Hi All,
>>
>> I've spent the last few months trying to see what Double High
>> Resolution Graphics (DHGR) is really capable of. It's a work in
>> progress but the results look promising.
>>
>> http://lukazi.blogspot.com.au/2017/03/double-high-resolution -graphics-dhgr.html
>>
>
> I am really impressed by what you guys are doing with Apple ][ graphics
> (you, B. Buckels, and all the other people already mentioned).
>
> I wonder if anyone has thought of combining such good images with a good
> plot for a text&graphics adventure game.
>
> Nicola


I have...

My focus is Networked Games, of the Text, Text/Graphics and Graphics
variety.. So, if they can be Networked, they Could also be Stand Alone..

MarkO
Re: What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340217 is a reply to message #340204] Sat, 25 March 2017 15:02 Go to previous messageGo to next message
Michael J. Mahon is currently offline  Michael J. Mahon
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Registered: October 2012
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Senior Member
Zellyn <zellyn@gmail.com> wrote:
> A couple of further thoughts after reading the whole thing.
>
> 1. If you have a Mac, definitely give 4am's OpenEmulator build a try: I
> think you'll be astonished at just how good the NTSC emulation is: choose
> the color monitor with all the settings, and you can tweak away until it
> matches what you're seeing on your actual CRT. You need 4am's build
> because my IIe changes are still in progress...
>
> 2. I have been thinking of porting the OpenEmulator NTSC emulation to a
> standalone library, to a web GL shader, and to non-gpu normal Go code.
> Sounds like I should get busy!
>
> 3. I've been wondering about the idea of dithering and DHGR as a
> maximization problem: use the NTSC emulation to render; then score the
> difference from the rendered image using a weighted combination of
> gaussian blurs of different radii, and possibly some edge detectors; then
> just randomly toggle bits and accept changes that improve the score. If
> anyone here understood this paragraph and has ideas, thoughts,
> suggestions, or pointers to literature, let me know :-)
>
> Zellyn
>

Several times in the past I've suggested that a shift register long enough
to span a microsecond or so (14 to 16 bits) would capture enough "video
context" to nicely emulate NTSC processing.

The (say) 16 bits would index R, G, and B tables computed from the DSP
emulation of NTSC processing, so you'd have the color rendering of real
NTSC with only a table lookup that should be trivial on modern processors.

The point of using a longer-than-usual shift register is that for faithful
NTSC rendering, it's necessary to span enough time to cover the
approximately 1MHz bandwidth of the chrominance filters.

--
-michael - NadaNet 3.1 and AppleCrate II: http://michaeljmahon.com
Re: What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340251 is a reply to message #340200] Sat, 25 March 2017 22:14 Go to previous messageGo to next message
Bill Buckels is currently offline  Bill Buckels
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Registered: November 2012
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Senior Member
"Lukazi" <lukazi@hotmail.com> wrote:
> http://lukazi.blogspot.com.au/2017/03/double-high-resolution -graphics-dhgr.html

So I posted this announcement in the Apple II Enthusiasts FaceBook group
this AM and you have 19 likes and 1 love so far... some people are enjoying
reading about this Alex...

Don't worry... I'm not done thinking about better conversions and agree that
more can be done.

Bill
What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340253 is a reply to message #340200] Sat, 25 March 2017 22:52 Go to previous messageGo to next message
Michael AppleWin Debu is currently offline  Michael AppleWin Debu
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Registered: March 2013
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Senior Member
WOW.

Stunning work !! Very, very nice.

Just a FYI side-note: in AppleWin 1.26 you can _fully_ tweak the 64x256 = 16,384 palette colors.
If you haven't seen this, this will give you some ides:

http://michael.peopleofhonoronly.com/dev/applewin/ntsc/

It looks like you were using Sheldon's NTSC AppleWin build which has white ringing, black ghosting, and white chroma ghosting.

Please keep us updated!
Re: What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340257 is a reply to message #340201] Sun, 26 March 2017 01:03 Go to previous messageGo to next message
STYNX is currently offline  STYNX
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Registered: October 2012
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Senior Member
On Saturday, March 25, 2017 at 3:02:15 PM UTC+1, Bill Buckels wrote:
> "Lukazi" <lu...@hotmail.com> wrote:
>> I've spent the last few months trying to see what Double High Resolution
>> Graphics (DHGR) is really capable of.
>
> When you find-out let me know... so far yours are roughly equal to what
> Sheldon Simms, Blurry, and I have produced. Good article too...
>
> The DHGR converters that we have today produce infinetly superior results
> than anything historically produced in the 80's and 90's that I am aware of.
>
> Bill

I think that Sheldon has gone bit further than the currently possible. The Images are near photo realistic.
Bill, your implementation is very good and easy to use but Sheldon took the NTSC artifacts into his conversion. If we could combine your work with his work and D. Brock puts it into the buckshot or something :-)

Its that a standard A2e can produce nicer images than the C64 :-P

-Jonas
Re: What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340595 is a reply to message #340257] Wed, 29 March 2017 13:22 Go to previous messageGo to next message
BLuRry is currently offline  BLuRry
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Registered: October 2012
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Senior Member
On Sunday, March 26, 2017 at 12:03:49 AM UTC-5, STYNX wrote:
> On Saturday, March 25, 2017 at 3:02:15 PM UTC+1, Bill Buckels wrote:
>> "Lukazi" <lu...@hotmail.com> wrote:
>>> I've spent the last few months trying to see what Double High Resolution
>>> Graphics (DHGR) is really capable of.
>>
>> When you find-out let me know... so far yours are roughly equal to what
>> Sheldon Simms, Blurry, and I have produced. Good article too...
>>
>> The DHGR converters that we have today produce infinetly superior results
>> than anything historically produced in the 80's and 90's that I am aware of.
>>
>> Bill
>
> I think that Sheldon has gone bit further than the currently possible. The Images are near photo realistic.
> Bill, your implementation is very good and easy to use but Sheldon took the NTSC artifacts into his conversion. If we could combine your work with his work and D. Brock puts it into the buckshot or something :-)
>
> Its that a standard A2e can produce nicer images than the C64 :-P
>
> -Jonas

The Outlaw converter also takes artifacts into account. It's a bit sloppy but essentially it does a brute-force match for every bit position and does a total error distance function to see if turning a bit on or off is a closer "match" to the desired pixels in the whole area (not just the target pixel it affects) For HGR, this is done for both hi and lo order combinations and the winner is chosen after both closest matches are calculated. The error propagation is performed once the winner is chosen. This has interesting side effects like it selecting the combinations of HGR bytes that yield pixels that are 25% or 75% width such as the occasional brown or yellow.

I can't pretend to be an expert, but I decided the best thing to do is let folks adjust the error correction rules to suit their fancy. All the error propagation rules are tweakable so you can pick Fast-Floyd-Steinberg or Atkinson, etc. I would say that it's worth desaturating an image a litte bit before trying to convert it or mess with brightness/contrast of the original as it can help surface better detail in the conversion.

I recently added an option to Outlaw which lets you export a full HGR or DHGR screen as a monitor listing to the clipboard. Previously it would save the binary data as a file but that was probably not as convenient. There's been other improvements to the drawing mode to speed things up a little and have multiple levels of undo as well as working zoom controls. It's not perfect but it works.

-B
Re: What is DHGR really capable of? Not content with existing A2 graphic converters? [message #340603 is a reply to message #340203] Wed, 29 March 2017 13:29 Go to previous message
BLuRry is currently offline  BLuRry
Messages: 489
Registered: October 2012
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Senior Member
On Saturday, March 25, 2017 at 9:38:09 AM UTC-5, Nicola wrote:
> On 25/03/2017 14:51, Lukazi wrote:
>> Hi All,
>>
>> I've spent the last few months trying to see what Double High
>> Resolution Graphics (DHGR) is really capable of. It's a work in
>> progress but the results look promising.
>>
>> http://lukazi.blogspot.com.au/2017/03/double-high-resolution -graphics-dhgr.html
>
> I am really impressed by what you guys are doing with Apple ][ graphics
> (you, B. Buckels, and all the other people already mentioned).
>
> I wonder if anyone has thought of combining such good images with a good
> plot for a text&graphics adventure game.
>
> Nicola

OR what about an RPG? This is how we made the graphics for Ancient Legends.. Most of the graphics were scanned from out-of-copyright or otherwise public domain images and then touched-up by hand. A lot of the images, even in HGR, have nice smoothed anti-aliased edges and so on, a nice artifact of this kind of conversion process.

-B
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