Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / image-1.0.15 / bmpwrite.m

diff --git a/octave_packages/image-1.0.15/bmpwrite.m b/octave_packages/image-1.0.15/bmpwrite.m
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+++ b/octave_packages/image-1.0.15/bmpwrite.m
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+## -*- texinfo -*-
+## @deftypefn {Function File} bmpwrite (@var{X}, @var{map}, @var{file})
+## Write the bitmap @var{X} into @var{file} (8-bit indexed uncompressed).
+## The values in @var{X} are indices into the given RGB colour @var{map}.
+## @deftypefnx{Function File} bmpwrite (@var{X}, @var{file})
+## Write the bitmap @var{X} into @var{file} (24-bit truecolor uncompressed).
+## @var{X} is an m x n x 3 array of R,G,B integer values in the range 0 to 255.
+## @end deftypefn
+
+## This code is in the public domain.
+## Author: Paul Kienzle <pkienzle@users.sf.net>
+
+
+function bmpwrite(x,colormap_or_file,file)
+  if nargin==2
+     bmpwrite_truecolor(x(:,:,1),x(:,:,2),x(:,:,3),colormap_or_file);
+  else
+     bmpwrite_indexed(x,colormap_or_file,file);
+  endif
+endfunction
+
+function bmpwrite_truecolor(R,G,B,file)
+    h = rows(R); w = columns(R);
+    padw = ceil(3*w/4)*4-3*w;
+    header = 14+40;
+    filesize = header+h*(3*w+padw);
+    arch = "ieee-le";
+    file = fopen(file, "wb");
+    fwrite(file,toascii("BM"),"uchar",0,arch); # file tag
+    fwrite(file,filesize,"long",0,arch);    # length of file
+    fwrite(file,0,"long",0,arch);           # reserved
+    fwrite(file,header,"long",0,arch);      # offset of raster data in file
+
+    fwrite(file,40,"long",0,arch);          # header size
+    fwrite(file,w,"long",0,arch);           # image width
+    fwrite(file,h,"long",0,arch);           # image height
+    fwrite(file,1,"short",0,arch);          # number of planes
+    fwrite(file,24,"short",0,arch);         # pixels per plane
+    fwrite(file,0,"long",0,arch);           # compression (none)
+    fwrite(file,0,"long",0,arch);           # compressed size of image
+    resolution = 72/2.54*100;               # 72 dpi / 2.54 cm/in * 100 cm/m
+    fwrite(file,resolution,"long",0,arch);  # horizontal resolution
+    fwrite(file,resolution,"long",0,arch);  # vertical resolution
+    fwrite(file,0,"long",0,arch);           # number of colours used
+    fwrite(file,0,"long",0,arch);           # number of "important" colors
+
+    ## raster image, lines written bottom to top.
+    R = R(end:-1:1,:)';
+    G = G(end:-1:1,:)';
+    B = B(end:-1:1,:)';
+    RGB=[B(:),G(:),R(:)]';  # Now [[B;G;R],[B;G;R],...,[B;G;R]]
+    RGB=reshape(RGB,3*w,h); # Now [[B;G;R;...;B;G;R],...,[B;G;R;...;B;G;R]]
+    fwrite(file,[RGB;zeros(padw,h)],"uchar",0,arch);
+    fclose(file);
+endfunction
+
+function bmpwrite_indexed(x,map,file)
+
+    if rows(map) > 256, 
+      bmpwrite_truecolor(reshape(map(x,1),size(x))*255,
+                        reshape(map(x,2),size(x))*255,
+                        reshape(map(x,3),size(x))*255,
+                        file);
+      return;
+    endif
+    [h,w] = size(x);
+    padw = ceil(w/4)*4-w;
+    header = 14+40+4*rows(map);
+    filesize = header+(w+padw)*h;
+    arch = "ieee-le";
+    file = fopen(file, "wb");
+    fwrite(file,toascii("BM"),"uchar",0,arch); # file tag
+    fwrite(file,filesize,"long",0,arch);    # length of file
+    fwrite(file,0,"long",0,arch);           # reserved
+    fwrite(file,header,"long",0,arch);      # offset of raster data in file
+
+    fwrite(file,40,"long",0,arch);          # header size
+    fwrite(file,w,"long",0,arch);           # image width
+    fwrite(file,h,"long",0,arch);           # image height
+    fwrite(file,1,"short",0,arch);          # number of planes
+    fwrite(file,8,"short",0,arch);          # pixels per plane
+    fwrite(file,0,"long",0,arch);           # compression (none)
+    fwrite(file,0,"long",0,arch);           # compressed size of image
+    resolution = 72/2.54*100;               # 72 dpi / 2.54 cm/in * 100 cm/m
+    fwrite(file,resolution,"long",0,arch);  # horizontal resolution
+    fwrite(file,resolution,"long",0,arch);  # vertical resolution
+    fwrite(file,rows(map),"long",0,arch);   # number of colours used
+    fwrite(file,0,"long",0,arch);           # number of "important" colors
+
+    ## colormap BGR0BGR0BGR0BGR0...
+    map=[round(map*255), zeros(rows(map),1)];
+    map=map(:,[3,2,1,4]);
+    fwrite(file,map',"uchar",0,arch);
+
+    ## raster image, each line on a 32-bit boundary, padded with zeros
+    ## lines written bottom to top.
+    fwrite(file,[flipud(x-1)';zeros(padw,h)],"uchar",0,arch);
+    fclose(file);
+endfunction