2000.01.29 19:27 "Re: tiff2ps: G4 compression in PostScript]", by Stanislav Brabec

I suspect that a PostScript interpreter has specific restrictions, then. I just ordered the "Green Book" on PostScript programming, so I'll see in a few days. I have all of the other PostScript books, all of the recent PostScript and PDF stuff of the Adobe site -- none of it sheds light on any of it. I hope the green book says "it has to be this-a-way" so we can get on with this.

I have looked to one of supplement files there and I found notices in TN5603 (see the end of file)

I have also tried to contact Adobe developers supoport:

First day I have been asked for my personal data.
Second day I have obtained human answer that I'm not registered (= paying) developer, so I must wait undefined time to answer.
Third day I have obtained answer from robot, that they are not help line for PostScript, because all can be found in PostScript Language Reference Manual.

I am adding test and info at the end of mail.

My last note about tiff2ps: Interpolate, in my opinion, should be optional.

Stanislav Brabec

5 CCITTFax Filters

CCITT stands for the Comité Consultatif International Télégraphique et Téléphonique. This filter type, known as CCITTFaxEncode and CCITTFaxDecode, is used for encoding and decoding facsimile (FAX) data according to the CCITT standards. This filter is primarily intended for encoding and decoding image data, not for communicating with FAX machines.

Note The CCITTFax filters accept an optional dictionary that includes the CloseTarget key for the encode filters and the CloseSource key for the decode filters.

The implementation-defined limit for the value of the Columns key in the decode dictionary has been increased from 25,000 to 62,000 for LanguageLevel 3.

Note There are C language source code files available for the CCITTFaxEncode and CCITTFaxDecode filters. These files are readme.fax, makefile, bitstm.h, ccmp.h, ccmpcode.h, ccmptab.h, cfaxfilt.h, protos.h, ccmpec.c, ccmpjc.c, flipbyte.c, revbits.c, and runtab0.c. Although these files were written to accompany an earlier level of the PostScript language, their information and use should still apply. Source code can be acquired under license through the Adobe Developers Association.

Note For more information on the CCITTFaxEncode and CCITTFaxDecode filters, see Section 3.3 of the Supplement: PostScript Language Reference Manual, or Sections 3.8.4 and 3.13 of the PostScript Language Reference Manual, Second Edition. See also Technical Note #5128, "PostScript Level 2 and Fax Modem Printing."

%!PS-Adobe-3.0
%%Creator: tiff2ps
%%Title: ccitttestg4.tif
%%CreationDate: Fri Nov 26 17:22:25 1999
%%DocumentData: Clean7Bit
%%Origin: 0 0
%%BoundingBox: 0 0 50 50
%%LanguageLevel: 2
%%Pages: (atend)
%%EndComments
%%BeginSetup
%%EndSetup
%%Page: 1 1
gsave
100 dict begin
50.000000 50.000000 scale
% PostScript Level 2 only.
/DeviceGray setcolorspace
{ % exec
<<
  /ImageType 1
  /Width 50
  /Height 50
  /ImageMatrix [ 50 0 0 -50 0 50 ]
  /BitsPerComponent 1
  /Interpolate true
  /Decode [0 1]
  /DataSource currentfile /ASCIIHexDecode filter
  <<
       /K -1
   /Columns 50
     /Rows 50
        /BlackIs1 true
>> /CCITTFaxDecode filter
>> image
}
%%BeginData:
exec
26a0a5ffffc86cbd3d7f4f9b5d2bd5faf56faf56faf5bd27ebd5bebd5bd2fa7d6faf56
faf56faf83f9402ef6740fc85d1bc8603f0674de41bd790ca0f07c835f63f0010010
%%EndData
end
grestore
showpage
%%Trailer
%%Pages: 1
%%EOF