Newsgroups: alt.cyberpunk.tech
Subject: Re: Resolution Vs Colors
From: PHUTTER@cardinal.sc107.wesleyan.edu (Macbeth)
Date: Wed, 16 Dec 1992 04:14:34 GMT
Organization: Wesleyan University, Middletown, CT USA

In article <1992Dec15.135858.26588@ee.rochester.edu> seah@ee.rochester.edu (David Seah) writes:
>Subject: Re: Resolution Vs Colors
>From: seah@ee.rochester.edu (David Seah)
>Date: 15 Dec 92 13:58:58 GMT

>Hmmm...the Resolution Vs Colors argument!  

>In article <PHUTTER.57.724270899@cardinal.sc107.wesleyan.edu> PHUTTER@cardinal.sc107.wesleyan.edu (Macbeth) writes:
>>In article <12DEC199200340539@sigma.tamu.edu> tww2568@sigma.tamu.edu (WEEKS, THOMAS WILLIAM) writes:
>>>Yes... the new higher resolutions are nice, but all in all, only DTP and other
>>>such resultion greedy applications need the such.. for the human eye, dealing w
>>>with lower contrast 256+ color pallets, you'll find MORE COLORS is better
>>>than higher res....

>A distinction you have to make is what your application is.  High _spacial_
>resolution provides more quantitative information, while high _color_
>resolution provides more of a qualitative one.  What does that mean?
>With high rez screens, you can show more characters of a more legible
>font and stuff more little symbols in the same amount of screen real estate.
>That's quantitative.  With lots of colors, you can make things look nice
>with subtle shading and snappy highlighting.  You can use color to do stuff
>like weather maps, which show the amount of precipitation or cloud cover
>through the use of different shades of color.  That's qualitative.  You
>can't extract hard data from this kind of display unless you severely
>limit the number and kinds of color.

>There is a limit to the number of distinguishable dots you can see...
>you can find these kinds of metrics in human-interface design references.
>So choose between pretty pictures and information content.  You can have
>both if you want.  

>>>After all... most of the REAL NICE TV sets with REAL NICE pictures are only
>>>about 500+ vertical lines....  
>>>Why do they look so nice then compared to my computer?
>>>   You ask...
>>
>>>Good question....  Its because the TV is displaying an analog representaion
>>>of the actual image... an image which in 'computer terms' is 24 bit, or 16.7
>>>million colors....  If you just stay at 640x480 res and jump from 256 colors
>>>to 32K, the improvement is incredible... much better than going to 1280x1024.
>>
>>This is not true. Television sets have something called anti-aliasing which 
>>the low-end to medium-end graphics boards (VGA to SuperVGA) do not have. 

>This is a minor nit, but televisions do not have an anti-aliasing circuit
>built in.  The anti-aliasing effect is a byproduct of the analog (or at
>least high S/N ratio) sampling of the cameras involved.  Incidentally, there
>are some medium-end products such as ATI's Graphic Ultra series which have
>anti-aliasing capabilities...whether this is clever hardware or clever
>drivers I can not say.  They call it their "CrystalFonts" technology.  There
>was also the ill-fated CEG chip, which was supposed to provide amazing
>improvements in apparent resolution without making a sacrifice in memory
>requirements...wonder what happened to it.  I heard it was tough to program.

>>[SNIP]
>>In many cases, professional graphics are rendered in 
>>24-bit (16M colors) and then converted to 8-bit (256 colors) with good 
>>conversion programs which keep the resolution and the graphic quality, while 
>>reducing the generating time and disk space.

>Hmmm...rendering in 24-bit color then quantizing to 8-bit indexed color
>would not reduce the generating time or the storage spac...you've still
>got to calculate and store those gigantic frames.  After you have the
>frame all done, you can quantize it and then reap savings benefits.

Nope, you take the 24-bit image, you convert it to an 8-bit image with 
reduced palette, and save it again, deleting the 24-bit one. The size 
usually goes down by 45%. I've tried it myself. It works!



>-- 
>Dave Seah ^..^   | Graduate MSEE, University of Rochester, New York           |
>                 | Apple II Graphics & Sound Forum Consultant, America Online |


>[Internet] seah@ee.rochester.edu, AFCDaveS@aol.com   [America Online] AFC DaveS