[arachne] DJPEG32.EXE Help File (???)

Arachne at FreeLists---The Arachne Fan Club!

Michal,
This is an outstanding example of an excellent response to a question.

I disagree only with the thought that an Arachne help file for DJPEG
wouldn't be a good option. I think that this material would be great in a
hyperlinked HTM or AH file. (I realize that some of this IS in the
Arachne documentation, but not in a comprehensive - and perhaps not
completely logical - manner).

But that is just my personal preference.

Thanks, Michal.

Bob

--------- Forwarded message ----------
From: "Michal H. Tyc" <mht@xxxxxxxxxxxxxxxx>
To: "Arachne4DOS" <arachne4dos@xxxxxxxxxxxx>
Date: Sat, 24 Jan 2004 07:58:46 -0800 (PST)
Subject: [a4dos-list] Re:Re:Re:Re: arachne.cfg variables... (was IMAGES
UPDATE was Re: Seasons Greetings)


Hi Greg, Hi all,

Greg Mayman wrote:

> And the one that was mentioned was not explained. The case in point is
> this:
> "JPEGargs"         -bmp|-bmp -fast (used by MIME.CFG macro $j)

> Checking on mime.cfg...
> ;  $j ... DJPEG arguments - ARACHNE.CFG variable DJPEGargs + color
depth, etc.

> and it all tells me... what? Should I include the "-fast" or not?
> If I do or don't, what difference will it make?

This option corresponds to Options|Preferences & Performance|Fast JPEGs
(OPT_MISC.AH) and is briefly explained there ("slightly lower quality").

From MIME.CFG, you know that $j delivers command line options to 
DJPEG32.EXE (or to DJPEG.EXE with 16BIT.APM installed):

image/jpeg JPG>BMP|$edjpeg32.exe $j $1 $2
file/.jpg     >BMP|$edjpeg32.exe $j $1 $2
file/.jpe     >BMP|$edjpeg32.exe $j $1 $2

so type "djpeg32 -?" (or just "djpeg") to get help:

usage: c:/arachne/djpeg32.exe [switches] inputfile outputfile
Switches (names may be abbreviated):
  -colors N      Reduce image to no more than N colors
  -fast          Fast, low-quality processing
  -grayscale     Force grayscale output
  -bmp           Select BMP output format (Windows style) (default)
  -gif           Select GIF output format
  -os2           Select BMP output format (OS/2 style)
Switches for advanced users:
  -dct int       Use integer DCT method (default)
  -dct fast      Use fast integer DCT (less accurate)
  -dct float     Use floating-point DCT method
  -dither fs     Use F-S dithering (default)
  -dither none   Don't use dithering in quantization
  -dither ordered  Use ordered dither (medium speed, quality)
  -map FILE      Map to colors used in named image file
  -nosmooth      Don't use high-quality upsampling
  -onepass       Use 1-pass quantization (fast, low quality)
  -maxmemory N   Maximum memory to use (in kbytes)
  -outfile name  Specify name for output file
  -verbose  or  -debug   Emit debug output

Unless you are an expert on computer graphics, you probably don't
know much more than before. But should Arachne documentation explain
the details of image processing algorithms used in a plug-in
application? I don't think so. To help to locate this information,
a note like "type DJPEG32 -? for option details" under $j explanation
in MIME.CFG should be sufficient.

> It is no explanation at all to anyone who is not familiar with
> the nitty-gritty of the code itself.

Only if you mean the code of DJPEG ;-)
-- as shown above.

Greetings,

Michal

-------- END OF FORWARDED MESSAGE ----------


Arachne at FreeLists
-- Arachne, The Web Browser/Suite for DOS and Linux --

Other related posts: