English Amiga Board Amiga Lore


Go Back   English Amiga Board > Main > Amiga scene

 
 
Thread Tools
Old 02 November 2016, 21:35   #61
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,532
Quote:
Originally Posted by britelite View Post
Or maybe rather a lack of interest, getting excited about displaying lots of colors on the Amiga is so 1985
Yep, true - 16 colors in hires should be enough for everyone...
pandy71 is offline  
AdSense AdSense  
Old 03 November 2016, 07:01   #62
britelite
Registered User
 
Join Date: Feb 2010
Location: Espoo / Finland
Posts: 242
Quote:
Originally Posted by pandy71 View Post
Yep, true - 16 colors in hires should be enough for everyone...
All 4096 colors (and more if you want to watch flickering like in the STe images you pasted) are available, even in hires, it's just a matter of generating a suitable copperlist.

I mean, on the ST/STe it actually takes some effort to get stable palette changes during refresh, so that's why it's impressive. But on the Amiga it's only a matter of making a suitable copper list, which makes it less impressive.

And the images you pasted are more about having made a nice converter for processing images to be displayable on the STe, the exact same images could most likely be displayed on the Amiga in exactly the same quality. And don't for a second think the images actually look like that when displayed on the STe
britelite is offline  
Old 03 November 2016, 07:20   #63
britelite
Registered User
 
Join Date: Feb 2010
Location: Espoo / Finland
Posts: 242
A nice example of hires on OCS with more than 16 colors on screen at once http://www.pouet.net/prod.php?which=68255
britelite is offline  
Old 03 November 2016, 10:01   #64
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,532
Quote:
Originally Posted by britelite View Post
All 4096 colors (and more if you want to watch flickering like in the STe images you pasted) are available, even in hires, it's just a matter of generating a suitable copperlist.
Nope as Copper will be unable to perform 40 CLUT changes per line in 4 bitplane hires on Amiga (CPU can change CLUT twice faster than Copper - perhaps some tricks like mask in BPLxDAT can be used to reduce overhead and improve perceived quality). And yes i'm fully aware of the limitations for temporal dithering however in LCD flickering will be less perceivable.

Quote:
Originally Posted by britelite View Post
I mean, on the ST/STe it actually takes some effort to get stable palette changes during refresh, so that's why it's impressive. But on the Amiga it's only a matter of making a suitable copper list, which makes it less impressive.
Yes, that's why i'm so impressed - poor ST need to to do many things that are available on Amiga for free yet ST is able to beat Amiga in visual quality due refining algorithms use for color quantization. Try to do same visual quality of conversion with Copper on Amiga 640x512 and only 2 bitplanes - result will be way worse... due of software quality not HW limitations.

Quote:
Originally Posted by britelite View Post
And the images you pasted are more about having made a nice converter for processing images to be displayable on the STe, the exact same images could most likely be displayed on the Amiga in exactly the same quality. And don't for a second think the images actually look like that when displayed on the STe
This was my point, significantly less capable HW but amazingly good software together delivered quality higher than Amiga.
How it looks on ST - true - have no clue but i know how it looks on screen and i'm impressed as even for today standards visual quality is more than just OK.

(and this explain why i decided to put those pictures inside topic related to demonstration pictures - we can't forget that HW capabilities are only one part of equation - software to deal with HW limitations is very important too - as ST case shows - HW limitations may be significantly reduced with proper SW approach).
pandy71 is offline  
Old 03 November 2016, 10:48   #65
britelite
Registered User
 
Join Date: Feb 2010
Location: Espoo / Finland
Posts: 242
Quote:
Originally Posted by pandy71 View Post
This was my point, significantly less capable HW but amazingly good software together delivered quality higher than Amiga.
You mean higher quality than current Amiga _SOFTWARE_.

But again, from a coders perspective this is less interesting on an Amiga, because there's really no challenge in displaying colorful pictures. So why waste time on image conversion when you could rather make something more interesting for the hardware.

Quote:
How it looks on ST - true - have no clue but i know how it looks on screen and i'm impressed as even for today standards visual quality is more than just OK.
To be honest, unless you've seen the images displayed on an STe, you only know how blended screenshots look.
britelite is offline  
Old 03 November 2016, 11:48   #66
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,532
Quote:
Originally Posted by britelite View Post
You mean higher quality than current Amiga _SOFTWARE_.
But again, from a coders perspective this is less interesting on an Amiga, because there's really no challenge in displaying colorful pictures. So why waste time on image conversion when you could rather make something more interesting for the hardware.
Yes, i mean software quality - and to be honest are you able to list few more interesting things for coders on HW - i will be glad to understand your way of thinking about interesting and less interesting things.

Quote:
Originally Posted by britelite View Post
To be honest, unless you've seen the images displayed on an STe, you only know how blended screenshots look.
Why such strange assumption - as electronics engineer working with video audio products i'm fully aware of temporal dithering and i know how it looks.
Temporal dithering is only one of problems and doesn't need to be used at all, proper color quantization, proper error distribution (i.e. dithering) and few other things are more important.
btw
Thanks for link to 'elevation by The Electronic Knights' - i checked YT movie and i realize that most of those picture may look same or marginally worse with colors (but with proper software).
Bellow pictures are 16 color fully Amiga compliant, no software tricks just good signal processing - 16 colors should be enough fer everyone (like 640KB of RAM) :











pandy71 is offline  
Old 03 November 2016, 12:47   #67
britelite
Registered User
 
Join Date: Feb 2010
Location: Espoo / Finland
Posts: 242
Quote:
Originally Posted by pandy71 View Post
Why such strange assumption - as electronics engineer working with video audio products i'm fully aware of temporal dithering and i know how it looks.
I was rather thinking of the interlace, especially if the images happen to use 3 or 4 fields (as suggested by dml's website). In which case a blended image and the actual interlaced image are two whole different beasts.
britelite is offline  
Old 03 November 2016, 15:56   #68
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,532
Quote:
Originally Posted by britelite View Post
I was rather thinking of the interlace, especially if the images happen to use 3 or 4 fields (as suggested by dml's website). In which case a blended image and the actual interlaced image are two whole different beasts.
Quote:
Originally Posted by britelite View Post
I was rather thinking of the interlace, especially if the images happen to use 3 or 4 fields (as suggested by dml's website). In which case a blended image and the actual interlaced image are two whole different beasts.
Interlace is a problem only when there is a motion not static and in fact it was a problem in CRT times, now LCD's are not affected by interlace at all.
And yes, temporal dithering combined with interlace will be disaster but... but we don't need to use temporal dither, and we don't need to use interlace - easily you can generate on Amiga 624/626p25 video (or by using ECS/AGA feature - i tested this in past and even ordinary CRT TV was capable to receive such signal or by software VHPOSW banging).

Side to this ST doesn't have real interlace - there is only field swapping but it is not real interlace (but Amiga has real interlace).
pandy71 is offline  
Old 03 November 2016, 18:27   #69
Phantasm
Not a Rebel anymore
 
Join Date: Apr 2005
Location: UK
Age: 44
Posts: 163
Quote:
Originally Posted by pandy71 View Post
Nope as Copper will be unable to perform 40 CLUT changes per line in 4 bitplane hires on Amiga (CPU can change CLUT twice faster than Copper - perhaps some tricks like mask in BPLxDAT can be used to reduce overhead and improve perceived quality). And yes i'm fully aware of the limitations for temporal dithering however in LCD flickering will be less perceivable.
what do you mean by 40 CLUT changes? are you suggesting that the CPU is capable of changing the whole CLUT table 40 times in a scanline? so 40*16 palette changes per scanline - that doesn't seem doable by an 8mhz cpu.
Phantasm is offline  
Old 03 November 2016, 18:37   #70
robinsonb5
Registered User
 
Join Date: Mar 2012
Location: Norfolk, UK
Posts: 509
Quote:
Originally Posted by Phantasm View Post
what do you mean by 40 CLUT changes?
Changes to 40 individual CLUT entries per scanline, perhaps?

What's the absolute maximum the CPU could manage with an unrolled movem loop, I wonder?
robinsonb5 is offline  
Old 03 November 2016, 21:14   #71
kovacm
Banned
 
Join Date: Jan 2012
Location: Serbia
Posts: 275
Quote:
Originally Posted by britelite View Post
Or maybe rather a lack of interest, getting excited about displaying lots of colors on the Amiga is so 1985
Yea, 16x16 sprite records are so much more excited... :P

On topic: @pandy, where did you get (find) this pictures from Atari?
kovacm is offline  
Old 04 November 2016, 00:30   #72
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,532
Quote:
Originally Posted by kovacm View Post
On topic: @pandy, where did you get (find) this pictures from Atari?
http://www.leonik.net/dml/sec_pcs.py

Great piece of code - really impressing (final quality can't be at this moment reproduced on Amiga even if same technique for CLUT change can be used).
pandy71 is offline  
Old 04 November 2016, 00:37   #73
kovacm
Banned
 
Join Date: Jan 2012
Location: Serbia
Posts: 275
Quote:
Originally Posted by pandy71 View Post
http://www.leonik.net/dml/sec_pcs.py

Great piece of code - really impressing (final quality can't be at this moment reproduced on Amiga even if same technique for CLUT change can be used).
ah, it is Doug converter (code).

He also make demo of scrolling Metal Slug level with same dual screen technics - it looks astonishing on real ST!
kovacm is offline  
Old 04 November 2016, 07:28   #74
britelite
Registered User
 
Join Date: Feb 2010
Location: Espoo / Finland
Posts: 242
Quote:
Originally Posted by pandy71 View Post
final quality can't be at this moment reproduced on Amiga even if same technique for CLUT change can be used.
Are you still only speaking of conversion software, because if the same technique for CLUT change is used, there's no reason why the converted data from the STe images couldn't be used on the Amiga.

EDIT: I mean, you make it sound like the Amiga technically couldn't achieve images like this, which is clearly wrong. If you only talk about the current state of software, then I might agree with you.

Last edited by britelite; 04 November 2016 at 07:34.
britelite is offline  
Old 04 November 2016, 12:45   #75
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,532
Quote:
Originally Posted by britelite View Post
Are you still only speaking of conversion software, because if the same technique for CLUT change is used, there's no reason why the converted data from the STe images couldn't be used on the Amiga.

EDIT: I mean, you make it sound like the Amiga technically couldn't achieve images like this, which is clearly wrong. If you only talk about the current state of software, then I might agree with you.
True but as you said for today ST is better not due HW but SW - for Amiga such things should be piece of cake yet there is no software capable to perform this for Amiga (of course ST/Win software can be used and result ported to Amiga but...).
pandy71 is offline  
Old 04 November 2016, 13:43   #76
vulture
Registered User
 
Join Date: Oct 2007
Location: Athens , Greece
Posts: 688
Isn't it on a Falcon?

Quote:
Originally Posted by kovacm View Post
ah, it is Doug converter (code).

He also make demo of scrolling Metal Slug level with same dual screen technics - it looks astonishing on real ST!
vulture is offline  
Old 04 November 2016, 14:15   #77
Thorham
Computer Nerd

Thorham's Avatar
 
Join Date: Sep 2007
Location: Rotterdam/Netherlands
Age: 41
Posts: 2,962
Quote:
Originally Posted by pandy71 View Post
Nope as Copper will be unable to perform 40 CLUT changes per line in 4 bitplane hires on Amiga (CPU can change CLUT twice faster than Copper
You don't have to, because the ST can only do 4 colors in hires. So yes, you can do this entirely with the copper.

The question is wether we need ugly flickering images on our Amigas or not. Really, 3 fields? Lololol
Thorham is offline  
Old 04 November 2016, 15:01   #78
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,532
Quote:
Originally Posted by Thorham View Post
You don't have to, because the ST can only do 4 colors in hires. So yes, you can do this entirely with the copper.
nope as Copper require two memory cycles to change CLUT - CPU can do this twice more frequently but even assuming Copper and 2 bitplanes so unthrottled Copper there is no software capable to provide such quality on 2 bitplanes - sad... and Amiga HW allow to use 16 colors not only 4 in 640 pixel mode so time requirements are significantly relaxed when compared to ST.

Quote:
Originally Posted by Thorham View Post
The question is wether we need ugly flickering images on our Amigas or not. Really, 3 fields? Lololol
Well, once again - temporal dither is highly optional - problem is somewhere else, side to this i believe that difference between 7 and 8 to create 7.5 with proper spatial dithering will be marginal (draw in interlace mode single line with grayscale 888 imposed on background 777) and there is a chance that on LCD it will be barely perceivable due nature of modern displays (btw temporal dithering is common practice nowadays in LCD's and PDP's - issue if refresh rate)
pandy71 is offline  
Old 04 November 2016, 15:06   #79
AnimaInCorpore
Registered User
 
Join Date: Nov 2012
Location: Willich/Germany
Posts: 146
Quote:
Originally Posted by Thorham View Post
The question is wether we need ugly flickering images on our Amigas or not. Really, 3 fields? Lololol
So have you seen that on a real hardware already?

The Amiga has a problem with 4096 colours as well: 16 shades per channel is quite insufficient for pictures with smooth gradients. It would be nice to display colours from a "simulated" 31 shades per channel palette using a simple alternating display technique.
AnimaInCorpore is online now  
Old 04 November 2016, 15:09   #80
Thorham
Computer Nerd

Thorham's Avatar
 
Join Date: Sep 2007
Location: Rotterdam/Netherlands
Age: 41
Posts: 2,962
Quote:
Originally Posted by pandy71 View Post
nope as Copper require two memory cycles to change CLUT
I'm pretty sure the copper can change one color every 8 lowres pixels if the screen depth isn't too high.

Quote:
Originally Posted by pandy71 View Post
but even assuming Copper and 2 bitplanes so unthrottled Copper there is no software capable to provide such quality on 2 bitplanes - sad...
All that's needed is a viewer and a conversion step from the ST format to Amiga. Both seem pretty trivial to me.

Quote:
Originally Posted by AnimaInCorpore View Post
So have you seen that on a real hardware already?
No, but I'm not sure I want to
Thorham is offline  
AdSense AdSense  
 


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
HAM6 on AGA in WinUAE displays incorrectly Photon support.WinUAE 12 29 March 2016 08:44
Converting JPG to HAM6/EHB with ImageStudio jman support.Apps 0 21 June 2011 17:42
Demonstration and Interview with Jan Derogee trackah123 Amiga scene 2 22 February 2009 13:19
Multiple HAM8 pictures? killergorilla support.Other 4 15 February 2007 14:41
First public demonstration of Dragon(Elbox) ppill News 15 09 December 2006 23:29

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 15:34.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Page generated in 0.36246 seconds with 12 queries