PROfft version 1.0 release date 29.4.1992

WHAT IS PROFFT?

PROfft stands for PROject Fast Fourier Transform and is the result of
a project developed by five students learning C++ at the Norwegian
Institute of Technology spring 1992.

The program allows to transform bitmap (.BMP) pictures using the fast
fourier transform. The resulting pictures will be displayed as according
to the mathematic formula [Grayscale Intensity]=LOG10(1+ABS(Z)) where
Z denotes the complex number after transforming the picture. There is
an option which allow the transforms to be shifted to the center of the
window (centered lower frequencies). You can also filter the pictures
using lowpass, highpass, bandpass, bandstop, butterworth lowpass and
highpass filters. In addition there is a "freehand" filter which allow
you to zero out certain frequencies in the transformed picture. Finally
the manipulated complex pictures can be transformed back again.

The program requires Windows 3.X to run, and preferably with a 256 colour
driver installed (although it will work perfectly with standard VGA).
The transformed pictures can be saved to disk or pasted into other
applications by using the clipboard.

The pictures to be transformed has to have the following characteristics:

  They must be square and their width and height has to be in a power of 2
  (16, 32, 64, ..., 2^n).

  They must be in the DIB (Device Independent Bitmap) format specified for
  Windows 3.X and OS/2. In addition they must have 8 bitplanes (that is a
  maximum of 256 colours/grayscales) and must have a grayscale palette.
  The palette is presumed to have colour 0 as black all the way up to
  255 as white (so that 127 equals 50% gray).


WHY IS IT HERE?

During the developement I've talked to different people using internet,
and at one time I mentioned that I could send people the project after
it was finished. One week later my mailbox was full with answers from
people everywhere. Not beeing able to reply to everyone I decided to
make it available through FTP (which is where this file originated from).



QUESTIONS?

Any questions concerning the system can be directed to:


Marius Kjeldahl
Klostergt. 56 - 27 C
N-7030 Trondheim
Norway

Phone priv. +47 7 503424
Phone work  +47 2 383910
Internet mariusk@lise.unit.no  (will not be replied during summer since then
                                I'm not at the campus..)