AWARE [SYSTEMS] Imaging expertise for the Delphi developer
AWare Systems, Imaging expertise for the Delphi developer, Home TIFF and LibTiff Mailing List Archive

LibTiff Mailing List

TIFF and LibTiff Mailing List Archive
June 1999

Previous Thread
Next Thread

Previous by Thread
Next by Thread

Previous by Date
Next by Date

Contact

The TIFF Mailing List Homepage
This list is run by Frank Warmerdam
Archive maintained by AWare Systems



Valid HTML 4.01!



Thread

1999.06.17 00:07 "Controlling Rational Values", by Tom Denny
1999.06.20 21:19 "Re: Controlling Rational Values", by Niles Ritter
1999.06.21 05:53 "Re: Controlling Rational Values", by Bjorn Brox
1999.06.21 07:12 "Re: Controlling Rational Values", by Niles Ritter
1999.06.21 07:48 "Re: Controlling Rational Values", by Bjorn Brox

1999.06.21 07:48 "Re: Controlling Rational Values", by Bjorn Brox

Niles Ritter wrote this:
> 
> Bjorn Brox wrote:
> 
> > Why make it so complex?
> 
> The solution is as simple as the nature of the general problem I had to solve,
> and no simpler.
> 
...
> However, if absolute size of a scanned target is important, and the original
> scanning resolution was 200:1, and if in an image processing program
> the original data was downsized by a factor of three, then the resulting
> TIFF image tags should be updated to read 200 / 3.
...
> XPosition
> YPosition
> WhitePoint
> PrimaryChromaticities
> YCbCrCoefficients

etc. etc.

Whatever solution you choose: When the number is 200.0, 150.0 etc, i.e. a
number without any decimals my code suggestion/trick would give a better
precision that yours, by storing these numbers as n/1:

    if (fv == (float)((int)fv)) {
        t[2*i+0] = (int)fv;
        t[2*i+1] = 1L;
    } else {

Trust me: it's simple and it works, and the "else" part is the original code
that might need some more tuning.

BTW: Have we got anyone to take over Sam's work on keeping the source
     control over libtiff?

-- 
Bjorn Brox, CORENA Norge AS, http://www.corena.no/
Kirkegaardsvn. 45, P.O.Box 1024, N-3601 Kongsberg, NORWAY
Phone: +47 32737435, Fax: +47 32736877, Mobile: +47 92638590