[Coco] The myth of the Coco3 256 color mode :)

[Stephen H. Fischer]

Hi,

Not only was it too long, I kept looking for some sign that it was 256 
colors and perhaps missed it. I watched the start and the end.

The static 64 color demo did show that ~ 64 colors were used, all 64 on the 
screen at once.

The demo could actually be using only 64 colors, but I think not as the 64 
color mode only allows 16 colors per line.

Some of the pictures appear to be using much less than 256 colors.

> I also included one picture that was not a photo but a computer generated 
> graphic.

Time code for that please.

> I was able to use a video capture card on a PC to make a video of a 
> slideshow I cooked up using the method Robert Gault is referring to.

How much of the poor quality is due to that.

I actually looked at it with no glasses, $4,400 well spent.

Somewhere on http://www.tandycoco.com/forum/index.php

there is a 256 color display suggesting what a FPGA could do, but I cannot 
find it.

(Not actual screen capture.)

SHF


----- Original Message ----- 
From: "Joel Ewy" <jcewy at swbell.net>
To: <coco at maltedmedia.com>
Sent: Tuesday, April 16, 2013 5:02 PM
Subject: Re: [Coco] The myth of the Coco3 256 color mode :)


> On 04/16/2013 04:49 PM, Stephen H. Fischer wrote:
>>
>> ----- Original Message ----- From: "Joel Ewy" <jcewy at swbell.net>
>> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
>> Sent: Tuesday, April 16, 2013 8:56 AM
>> Subject: Re: [Coco] The myth of the Coco3 256 color mode :)
>>
>>
>> Though the
>>>> conversion process resulted in pretty crummy video, the color 
>>>> artifacting worked like a charm, and the colors come out looking pretty 
>>>> much the same as they do on a monitor: 
>>>> http://www.youtube.com/watch?v=hjcUdoW0rrg
>>>>
>>> FWIW, I think the above URL might be an abridged version of the 
>>> slideshow. Not sure what that's about.  The whole thing seems to be 
>>> here: 
>>> http://www.youtube.com/watch?feature=player_detailpage&v=hjcUdoW0rrg
>>>
>>> JCE
>>
>> If it has been shortened, thanks.
>>
>> It was like watching a friends vacation slides without your glasses and 
>> wanting to go home.
>>
>> SHF
>>
>
> Sorry if you found the subject matter boring and the resolution low, 
> Stephen.  I chose photos that were Creative Commons licensed, so I could 
> legally include them in a derivative work, and that would demonstrate what 
> digital photos would look like using this method of display.  I tried to 
> pick a variety of subjects.  I wanted to show people, both close up and at 
> a little distance.  I wanted to show things that one might see in an 
> adventure game.  I also included one picture that was not a photo but a 
> computer generated graphic.
>
> Personally, watching the slideshow again, I am surprised at how good the 
> images look, aside from the messiness of the video capture.  Use 'view' in 
> NitrOS-9 to display a 256 color .gif and tell me how you think it looks 
> compared to the images I put in that slideshow. Remember, this is an 
> unmodified CoCo 3, and this uses no palette switching or screen flipping, 
> so it can be used in games, or anywhere else you can display a 640x200x4 
> image, as long as you have a composite monitor or TV.  The effective 
> resolution is low: 160x200.  But the added colors can make it well worth 
> the trade-off for some purposes.  If you want to see the best quality 
> representation of a digital photo the CoCo 3 can produce, try Sockmaster's 
> Hi-color program.  It's fantastic, though it still does have a little 
> glitchiness when the palette registers are updated, and some flicker, 
> though much less than most.  The problem is, that doesn't work in OS-9, 
> and it doesn't work as a slideshow, and it can't easily be used inside 
> other programs.
>
> One thing I've been playing with is the possibility of making a hybrid 
> image that superimposes high detail areas as a 4 gray 640x200 image on top 
> of the 160x200 artifact color image.  I remember from CoCo Max that while 
> you might get some unwanted artifacts (color error), you could still put a 
> lot of detail in a 256x192 image by treating it as a full-resolution B/W 
> bitmap, but use the red/blue artifacts to add color in larger areas.  From 
> what I understand, the human eye is more sensitive to shades of gray than 
> color, so rendering areas of detail in gray should make for a more 
> recognizable image, even if there are some unwanted color artifacts.  My 
> initial experiments are promising, but I don't have anything to show quite 
> yet.
>
> JCE
>