function bmpwrite(X,map, filename);

%BMPWRITE Write a BMP (Microsoft Windows Bitmap) file to disk.

%	BMPWRITE(X,MAP,'filename') writes a BMP file containing the

%	indexed image X and colormap MAP to a disk file called 'filename'.

%	If no file extension is given with the filename, the extension

%	'.bmp' is assumed.

%

%	See also: BMPREAD, GIFWRITE, HDFWRITE, PCXWRITE, TIFFWRITE,

%	          XWDWRITE.



%	Mounil Patel 3/10/94

%	Copyright (c) 1994 by The MathWorks, Inc.

%	$Revision: 1.13 $  $Date: 1995/02/09 15:28:11 $



if (nargin~=3)

	error('Requires three arguments.');

end;



if (isstr(filename)~=1)

	error('Requires a string filename as the third argument.');

end;



if (isempty(findstr(filename,'.'))==1)

	filename=[filename,'.bmp'];

end;



fid=fopen(filename,'wb','l');

if (fid==-1)

	error(['Error opening ',filename,' for output.']);

end;



fwrite(fid,[66;77],'uchar');



[biHeight,biWidth]=size(X);

% What will be the physical file size?  First term: image data,

% with width padded to be multiple of 4.  Second term: length of

% bitmap header.  Third term: length of bitmap information

% header.  Third term: length of color palette.

bfSize = biHeight*(biWidth+(4-rem(biWidth,4))) + 14 + 40 + 256*4;

fwrite(fid,bfSize,'uint');

bfReserved1=0;

fwrite(fid,bfReserved1,'ushort');

bfReserved2=0;

fwrite(fid,bfReserved2,'ushort');

bfOffBytes=1078;

fwrite(fid,bfOffBytes,'uint');

biSize=40;

fwrite(fid,biSize,'uint');



fwrite(fid,biWidth,'uint');

fwrite(fid,biHeight,'uint');

biPlanes=1;

fwrite(fid,biPlanes,'ushort');

biBitCount=8;

fwrite(fid,biBitCount,'ushort');

biCompression=0;

fwrite(fid,biCompression,'uint');

biSizeImage=biHeight*(biWidth+(4-rem(biWidth,4)));

fwrite(fid,biSizeImage,'uint');

biXPels=0;

fwrite(fid,biXPels,'uint');

biYPels=0;

fwrite(fid,biYPels,'uint');

biClrUsed=256;

fwrite(fid,biClrUsed,'uint');

biClrImportant=0;

fwrite(fid,biClrImportant,'uint');



[m,n]=size(map);

if (m<256)

	map=[map;zeros(256-m,3)];

elseif (m>256)

 error('Colormap exceeds 256 colors! Only 8-bit BMP file output is supported.');

end;



map=[fliplr(map*255),zeros(256,1)]';

fwrite(fid,map(:),'uchar');



X=(X-1);

if (rem(biWidth,4)~=0)

	X=[X,zeros(biHeight,4-rem(biWidth,4))];

end;

X=rot90(X,3);

fwrite(fid,X(:),'uchar');



fclose(fid);