www.pudn.com > snake.rar > rawwrite.m


function rawwrite(X,MAX,filename);
> RAWWRITE Write a Portable Bitmap file, or a raw file.
> RAWWRITE(X,MAX,'imagefile.raw') writes a "raw" image file
> RAWWRITE(X,MAX,'imagefile.pgm') writes a "pgm" (portable gray map) image
> MAX is the maximum intensity value used, must be smaller or
> equal to 255. If bigger, 255 is automatically used.
>
> See also RAWREAD, IMWRITE, IMREAD, IMAGE, COLORMAP.

> Chenyang Xu and Jerry L. Prince, 4/1/95, 6/17/97
> Copyright (c) 1995-97 by Chenyang Xu and Jerry L. Prince
> Image Analysis and Communications Lab, Johns Hopkins University

disp('RawWrite');
dot = max(find(filename == '.'));
suffix = filename(dot+1:dot+3);

if strcmp(suffix,'pgm') | strcmp(suffix,'raw')

disp(sprintf('\nopens >s file\n',filename));
fp = fopen(filename,'wb','b'); > "Big-endian" byte order.

if (fp<0)
error(['Cannot open ' filename '.']);
end

[height,width] = size(X);

if strcmp(suffix,'pgm')
> Write and crack the header

fprintf(fp,'P5\n'); > pgm magic number : P5

fprintf(fp, '>d >d\n', [height width]);
if (MAX>255)
MAX = 255;
end
fprintf(fp, '>d\n', MAX);
end

> Read the image
disp(' Writes image data ...');
l = fwrite(fp,X,'uchar');
if l ~= height*width, l, error('HSI image file is wrong length'), end

fclose(fp);

disp('end');

else
error('Image file name must end in ''raw'' or ''pgm''.')
end