Yamaha DSP-Z7 - Инструкция по эксплуатации - Страница 153

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The file format we have adopted is called JFIF (see REFERENCES). This format has 
been agreed to by a number of major commercial JPEG vendors, and it has become the 
de facto standard. JFIF is a minimal or “low end” representation. We recommend the use 
of TIFF/JPEG (TIFF revision 6.0 as modified by TIFF Technical Note #2) for “high 
end” applications that need to record a lot of additional data about an image. TIFF/JPEG 
is fairly new and not yet widely supported, unfortunately.

The upcoming JPEG Part 3 standard defines a file format called SPIFF. SPIFF is 
interoperable with JFIF, in the sense that most JFIF decoders should be able to read the 
most common variant of SPIFF. SPIFF has some technical advantages over JFIF, but its 
major claim to fame is simply that it is an official standard rather than an informal one. 
At this point it is unclear whether SPIFF will supersede JFIF or whether JFIF will 
remain the de-facto standard. IJG intends to support SPIFF once the standard is frozen, 
but we have not decided whether it should become our default output format or not. (In 
any case, our decoder will remain capable of reading JFIF indefinitely.)

Various proprietary file formats incorporating JPEG compression also exist. We have 
little or no sympathy for the existence of these formats. Indeed, one of the original 
reasons for developing this free software was to help force convergence on common, 
open format standards for JPEG files. Don’t use a proprietary file format!

TO DO

The major thrust for v7 will probably be improvement of visual quality. The current 
method for scaling the quantization tables is known not to be very good at low Q values. 
We also intend to investigate block boundary smoothing, “poor man’s variable 
quantization”, and other means of improving quality-vs-file-size performance without 
sacrificing compatibility.

In future versions, we are considering supporting some of the upcoming JPEG Part 3 
extensions --- principally, variable quantization and the SPIFF file format.
As always, speeding things up is of great interest.
Please send bug reports, offers of help, etc. to jpeg-info@uunet.uu.net.

■

About PNG Reference Library

libpng versions 1.2.6, August 15, 2004, through 1.2.29, May 8, 2008, are Copyright (c) 
2004, 2006-2008 Glenn Randers-Pehrson, and are distributed according to the same 
disclaimer and license as libpng-1.2.5 with the following individual added to the list of 
Contributing Authors

Cosmin Truta

libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are Copyright (c) 
2000-2002 Glenn Randers-Pehrson, and are distributed according to the same disclaimer 
and license as libpng-1.0.6 with the following individuals added to the list of 
Contributing Authors

Simon-Pierre Cadieux
Eric S. Raymond
Gilles Vollant

and with the following additions to the disclaimer:

There is no warranty against interference with your enjoyment of the library or 
against infringement. There is no warranty that our efforts or the library will fulfill 
any of your particular purposes or needs. This library is provided with all faults, 
and the entire risk of satisfactory quality, performance, accuracy, and effort is with 
the user.

libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are Copyright (c) 
1998, 1999 Glenn Randers-Pehrson, and are distributed according to the same 
disclaimer and license as libpng-0.96, with the following individuals added to the list of 
Contributing Authors:

Tom Lane
Glenn Randers-Pehrson
Willem van Schaik

libpng versions 0.89, June 1996, through 0.96, May 1997, are Copyright (c) 1996, 1997 
Andreas Dilger Distributed according to the same disclaimer and license as libpng-0.88, 
with the following individuals added to the list of Contributing Authors:

John Bowler
Kevin Bracey
Sam Bushell
Magnus Holmgren
Greg Roelofs
Tom Tanner

libpng versions 0.5, May 1995, through 0.88, January 1996, are Copyright (c) 1995, 
1996 Guy Eric Schalnat, Group 42, Inc.

For the purposes of this copyright and license, “Contributing Authors” is defined as the 
following set of individuals:

Andreas Dilger
Dave Martindale
Guy Eric Schalnat
Paul Schmidt
Tim Wegner

The PNG Reference Library is supplied “AS IS”. The Contributing Authors and Group 
42, Inc. disclaim all warranties, expressed or implied, including, without limitation, the 
warranties of merchantability and of fitness for any purpose. The Contributing Authors 
and Group 42, Inc. assume no liability for direct, indirect, incidental, special, exemplary, 
or consequential damages, which may result from the use of the PNG Reference Library, 
even if advised of the possibility of such damage.

Permission is hereby granted to use, copy, modify, and distribute this source code, or 
portions hereof, for any purpose, without fee, subject to the following restrictions:

1.

The origin of this source code must not be misrepresented.

2.

Altered versions must be plainly marked as such and must not be misrepresented 
as being the original source.

3.

This Copyright notice may not be removed or altered from any source or altered 
source distribution.

The Contributing Authors and Group 42, Inc. specifically permit, without fee, and 
encourage the use of this source code as a component to supporting the PNG file format 
in commercial products. If you use this source code in a product, acknowledgment is not 
required but would be appreciated.

■

About zlib Library

Copyright notice:
(C) 1995-2004 Jean-loup Gailly and Mark Adler

This software is provided ’as-is’, without any express or implied warranty. In no event 
will the authors be held liable for any damages arising from the use of this software.

Permission is granted to anyone to use this software for any purpose, including 
commercial applications, and to alter it and redistribute it freely, subject to the following 
restrictions:

1.

The origin of this software must not be misrepresented; you must not claim that 
you wrote the original software. If you use this software in a product, an 
acknowledgment in the product documentation would be appreciated but is not 
required.

2.

Altered source versions must be plainly marked as such, and must not be 
misrepresented as being the original software.

3.

This notice may not be removed or altered from any source distribution.

Jean-loup Gailly

Mark Adler

jloup@gzip.org

madler@alumni.caltech.edu

If you use the zlib library in a product, we would appreciate *not* receiving lengthy 
legal documents to sign. The sources are provided for free but without warranty of any 
kind. The library has been entirely written by Jean-loup Gailly and Mark Adler; it does 
not include third-party code.

If you redistribute modified sources, we would appreciate that you include in the file 
ChangeLog history information documenting your changes. Please read the FAQ for 
more information on the distribution of modified source versions.