pgm2x.m~

this a SVM toolbox,it is very useful for someone who just learn SVM.In order to be undestood easily,

function [X,width,height]=pgm2x(fname)
% [X,width,height]=pgm2x(fname)
%
% PGM2X reads an image from fname which must be in the PGM 
%  format. The read image is returned as a column vector 
%  (double) normalized to <0,1>.
%  
% Input:
%  fname [string] file nam of the image.
%
% Output:
%  X [width x height] vector containg read image.
%  width [1x1] width of the image.
%  height [1x1] height of the image.
%
% See also X2PGM
%

% Statistical Pattern Recognition Toolbox, Vojtech Franc, Vaclav Hlavac
% (c) Czech Technical University Prague, http://cmp.felk.cvut.cz
% Written Vojtech Franc (diploma thesis)
% Modifications
% 26-feb-2001 V.Franc


fid=fopen(fname,'r');

line1=fgets(fid);
line2=fgets(fid);
line3=fgets(fid);


a = sscanf(line2,'%d');
width=a(1);
height=a(2);

prec= sscanf(line3, '%d');

if  prec==255,
  precision='uchar';
elseif prec==65535,
  precision='int16';
end

[X, count] = fread(fid,inf,precision);
fclose(fid);

if count ~= width*height,
  error('Invalid input format.');
  return;
end

X=X(:);

X=double(X)/prec;

return;