🚀 go-pugleaf

In article <1992Jul27.100116.9655@waikato.ac.nz>, singlis@waikato.ac.nz writes:
|> Path: ucdavis!ucbvax!agate!ames!sun-barr!cs.utexas.edu!wupost!waikato.ac.nz!singlis
|> From: singlis@waikato.ac.nz
|> Newsgroups: sci.image.processing
|> Subject: Filter Ranges for Enhancement, HELP!?!
|> Message-ID: <1992Jul27.100116.9655@waikato.ac.nz>
|> Date: Sun, 26 Jul 92 15:01:16 GMT-0:06
|> Organization: University of Waikato, Hamilton, New Zealand
|> Lines: 20
|> 
|> Greetings,
|> 
|> when filtering with a standard Laplacian filter
|> 	[ -1  -1  -1 ]
|> 	[ -1   8  -1 ]
|> 	[ -1  -1  -1 ]
|> and assuming the pixel values from 0..1 in intensity, the result of the 
|> operation can range from -8.0 to 8.0. What is the standard way of
|> mapping this result to a pixel range.
|> 
|> I have tried just diving by 8.0, and if negative ignore but this just gives
|> "black" images, I also tried /8.0 and the absolute, still it looks terrible.
|> 
|> I have a program for the PC, Improces which does a nice job.
|> 
|> Could anyone give me some tips??
|> 
|> thanks in advance
|> 
|> -Stuart Inglis, Waikato University, Hamilton, New Zealand.
|> 


scale it up beteen 0-range as follows:

range = 1.0;

for(i=0; i<dimension; i++)
  for(j=0; j<dimension; j++)
   scaled_image[i][j] = (range(image[i][j] - minimum))/(maximum-minimum);

/* where image[i][j] is your filtered image 
   minimum is minimum value of the filtered image 
   maximum  is maximum value of the filtered image 

   if you want to map between 0-255 simply change the range to 255

*/

-Iftekhar