ref: 9861f1a92b373a16939fd6f3c167e5dad9f253d3
dir: /sys/src/cmd/gs/lib/viewmiff.ps/
% Copyright (C) 1998 Aladdin Enterprises. All rights reserved.
%
% This software is provided AS-IS with no warranty, either express or
% implied.
%
% This software is distributed under license and may not be copied,
% modified or distributed except as expressly authorized under the terms
% of the license contained in the file LICENSE in this distribution.
%
% For more information about licensing, please refer to
% http://www.ghostscript.com/licensing/. For information on
% commercial licensing, go to http://www.artifex.com/licensing/ or
% contact Artifex Software, Inc., 101 Lucas Valley Road #110,
% San Rafael, CA 94903, U.S.A., +1(415)492-9861.
% $Id: viewmiff.ps,v 1.4 2002/02/21 21:49:28 giles Exp $
% viewmiff.ps
% Display a MIFF file. You would think the 'display' command would do this,
% but many versions of 'display' either core-dump or require unacceptably
% large amounts of memory.
% Recognize MIFF keywords.
/miffwords mark
/class { cvn /class exch def }
/colors { cvi /colors exch def }
/columns { cvi /Width exch def }
/compression { cvn /compression exch def }
/depth { cvi /depth exch def }
/packets { cvi /packets exch def }
/rows { cvi /Height exch def }
.dicttomark readonly def
% Recognize MIFF image classes.
/miffclasses mark
/DirectClass {
/DeviceRGB setcolorspace
/BitsPerComponent depth def
/Decode [ 0 1 0 1 0 1 ] def
}
/PseudoClass {
[ /Indexed
% The MIFF documentation lies about the size of pixels
% for this case: the pixel size is determined only by
% the number of colors, and is not affected by the image
% depth. Specifically, if there are 256 or fewer colors
% but the depth (of color map entries) is 16, each pixel
% is still only 1 byte, not 2.
currentdict /colors known {
/DeviceRGB colors 1 sub
/BitsPerComponent colors 256 le { 8 } { 16 } ifelse def
colors 3 mul string depth 8 eq {
f exch readstring pop
} {
% 16-bit color map entries: take only the high-order byte.
0 1 2 index length 1 sub {
f read pop 2 index 3 1 roll put f read pop pop
} for
} ifelse
} {
/colors 256 def
/DeviceGray 255
256 string 0 1 255 { 1 index exch dup put } for
} ifelse
] setcolorspace
/Decode [ 0 1 BitsPerComponent bitshift 1 sub ] def
}
.dicttomark readonly def
% Recognize MIFF compression methods.
/rlstring 768 string def
/rlread {
% packets is not reliable -- disregard it.
dup rlstring 0 3 getinterval readstring {
pop read pop 3 mul 3 3 2 index {
rlstring exch rlstring 0 3 getinterval putinterval
} for
rlstring 0 3 -1 roll 3 add getinterval
} {
pop pop ()
} ifelse
} bind def
/miffcompress mark
/Uncompressed { f }
/RunLengthEncoded { { f rlread } }
/Zip { [ f /FlateDecode filter cvlit /rlread cvx ] cvx }
.dicttomark readonly def
% Read a MIFF file and display the image.
/viewmiff { % <filename> viewmiff -
50 dict begin
/fname 1 index def
/f exch (r) file def
% Set defaults.
/ImageType 1 def
/class /DirectClass def
/compression /Uncompressed def
/depth 8 def
/packets 16#7fffffff def
% Read and parse the header.
{ f token pop
dup (:) eq { pop exit } if
dup type /nametype eq {
.namestring (=) search {
exch pop miffwords exch .knownget { exec } { pop } ifelse
} {
pop % who knows?
} ifelse
} {
pop % probably a comment in braces
} ifelse
} loop
% Read and display the image.
miffclasses class get exec
/DataSource miffcompress compression get exec def
/ImageMatrix [Width 0 0 Height neg 0 Height] def
currentpagedevice /PageSize get
dup 0 get exch 1 get scale
gsave 0.8 setgray 0 0 1 1 rectfill grestore % provide background
currentdict image
showpage
% Clean up.
f closefile
end
} bind def