image shows only half of edge pixels

[lynx . abraxas]

Hello!


Trying to find a way to convert a bitmap into a vector image by simply drawing
a rectangle for each pixel I found octaves can do  that.  I  made  the  little
script  below.  But  my  problem is that the pixels on the edge are only shown
half in the svg-result. What can I do about that?

Thanks for any help or hints
Lynx
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arg_list = argv ();
if nargin < 1
  printf("Usage: %s <bitmap.ppm>\n", program_name);
  exit(1)
endif

#I= loadimage(arg_list{1});
I= imread(arg_list{1});
figure(1, 'visible', 'off');
image(I);
axis ("equal");
shading flat;
print(sprintf("%s.svg", arg_list{1}), '-dsvg');