Converting spatial resolution to intensity resolution

Converting spatial resolution to intensity resolution

Post by venu.p.gop » Tue, 02 Oct 1990 21:32:00



Has anyone written a program that takes a high resolution monochrome
image (only two levels of intensity - black and white) and converted
it to low resolution image but with greyscale information ?  Thus
trading off spatial resolution for intensity resolution..

I am interested in looking at the results of such conversions and
also in such a  program itself.  TIFF or GIF pics if possible, else
any file format.


 
 
 

Converting spatial resolution to intensity resolution

Post by Paul Eric Mench » Tue, 02 Oct 1990 04:10:00



>Has anyone written a program that takes a high resolution monochrome
>image (only two levels of intensity - black and white) and converted
>it to low resolution image but with greyscale information ?  Thus
>trading off spatial resolution for intensity resolution..

On the Mac a program called Vision Lab does this kind of thing.  It is
available at sumex-aim.stanford.edu in /info-mac/demo.  It converts
from all sorts of file formats to all other sorts of file formats.
Specifically, in regard to your question, it can take MacPaint files
which are only black and white and "undigitize" them its words.  This
produces a grey-scale image reduced 33 or 50% (you determine) in size.
You can then save this in whatever form you like.  The image could be
scaled to produce a low-res of the original.  I've been very impressed
with the program and only wish the author included his address so I
could get a full featured version.

    /--------------      
   /         /|  /|  Paul Eric Menchen        


/__________________

 
 
 

Converting spatial resolution to intensity resolution

Post by Neil Hu » Tue, 02 Oct 1990 20:36:00



>Has anyone written a program that takes a high resolution monochrome
>image (only two levels of intensity - black and white) and converted
>it to low resolution image but with greyscale information ?  Thus
>trading off spatial resolution for intensity resolution..

Check out Dvipage, which renders a page of a document typeset by TeX or*
using 300 dot per inch bilevel fonts (the same bits used for a LaserWriter)
and then performs averaging and sampling to produce 75 dot per inch
grey scale pages for display on a colour sun.  Lookup tables are used
extensively to enable the conversion process to be performed in about
2 to 5 seconds on sun 4/260 and 3/160 respectively, for 8.5x11 inch pages
(~8.5e6 pixels).  (Other operating modes are also supported.)

Dvipage (3.0) is available (in source) from june.cs.washington.edu, or from
the sun spots archive. I believe that these sources also have the patches
for PK font reading.  (As far as I can tell, no one has made dvipage work
on a 386i yet, due to byte order problems.)


 
 
 

Converting spatial resolution to intensity resolution

Post by Dave Levins » Tue, 02 Oct 1990 14:03:00


Hello,

There is a company called RIX that writes a program called ColoRIX
(SuperVGA paint program) that has a converter included. This converter
handles and supported modes from monochrome to high res 256 color formats
(IBM 8514). It will average the image so it may need a little work done
after, but it works. They also do 64 bit grayscale upon loading the image
that is great.
 I have also posted a text file on this BBS (The Business 1-407-628-2018,
Orlando, FL, TGLPLUS.TXT in Business Stuff 4th floor ) that is technical
info on a new converter. The converter does a hell of alot and possibly what
you need as well. Good luck, let me know what happens!    Dave L.  

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