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List:       kde-commits
Subject:    extragear/graphics/doc/digikam
From:       Laurent Espitallier <laurent.espitallier () laposte ! net>
Date:       2010-02-28 23:05:30
Message-ID: 1267398330.618265.16660.nullmailer () svn ! kde ! org
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SVN commit 1097343 by lespitallier:

PGF format support (minor corrections)

 M  +2 -1      file-formats.docbook  
 M  +1 -1      index.docbook  


--- trunk/extragear/graphics/doc/digikam/file-formats.docbook \
#1097342:1097343 @@ -63,7 +63,8 @@
             </sect3>
 
             <sect3>            <title>PGF</title>
-	    <para> "Progressive Graphics File" is another not so known but open \
file image format. Wavelet-based, it allows lossless and lossy data \
compression. PGF compares well with JPEG 2000 but it was developed for \
speed (compression/decompression) rather than to be the best at compression \
ratio. At the same file size a PGF file looks significantly better than a \
JPEG one, while remaining very good at progressive display too. Thus, it \
should be well-suited to the web.  For more information about the PGF \
format see the <ulink url="http://www.libpgf.org/">PGF homepage</ulink>. +	 \
<para> +                "Progressive Graphics File" is another not so known \
but open file image format. Wavelet-based, it allows lossless and lossy \
data compression. PGF compares well with JPEG 2000 but it was developed for \
speed (compression/decompression) rather than to be the best at compression \
ratio. At the same file size a PGF file looks significantly better than a \
JPEG one, while remaining very good at progressive display too. Thus it \
should be well-suited to the web but at the moment few browsers can display \
it. For more information about the PGF format see the <ulink \
url="http://www.libpgf.org/">libPGF homepage</ulink>.  </para> 
 
             </sect3>
--- trunk/extragear/graphics/doc/digikam/index.docbook #1097342:1097343
@@ -1471,7 +1471,7 @@
 	<para><command>GIF</command> is a proprietary. patented format and slowly \
disappearing from the market. Don't use it.</para>  \
<para><command>PNG</command> has been invented as a Open Source standard to \
replace GIF, but it does much more. It is lossless, supports XMP, EXIF and \
IPTC metadata, 16 bit color encoding and full transparency. PNG can store \
gamma and chromaticity data for improved color matching on heterogeneous \
platforms. Its drawback are a relatively big footprints (but smaller than \
TIFF) and slow compression. We recommend it.</para>  \
<para><command>TIFF</command> has been widely accepted as an image format. \
TIFF can exist in uncompressed form or in a container using a lossless \
compression algorithm (Deflate). It maintains high image quality but at the \
expense of much larger file sizes. Some cameras let you save your images in \
this format. The problem is that the format has been altered by so many \
people that there are now 50 or more flavors and not all are recognizable \
                by all applications.</para>
-	<para><command>PGF</command> "Progressive Graphics File" is another not \
so known but open file image format. Wavelet-based, it allows lossless and \
lossy data compression. PGF compares well with JPEG 2000 but it was \
developed for speed (compression/decompression) rather than to be the best \
at compression ratio. At the same file size a PGF file looks significantly \
better than a JPEG one, while remaining very good at progressive display \
too. Thus, it should be well-suited to the web. For more information about \
the PGF format see the <ulink url="http://www.libpgf.org/">PGF \
homepage</ulink>.</para>  +	<para><command>PGF</command> "Progressive \
Graphics File" is another not so known but open file image format. \
Wavelet-based, it allows lossless and lossy data compression. PGF compares \
well with JPEG 2000 but it was developed for speed \
(compression/decompression) rather than to be the best at compression \
ratio. At the same file size a PGF file looks significantly better than a \
JPEG one, while remaining very good at progressive display too. Thus it \
should be well-suited to the web but at the moment few browsers can display \
it. For more information about the PGF format see the <ulink \
url="http://www.libpgf.org/">libPGF homepage</ulink>.</para>  \
<para><command>RAW</command> format. Some, typically more expensive, \
cameras support RAW format shooting. The RAW format is not really an image \
standard at all, it is a container format which is different for every \
brand and camera model. RAW format images contain minimally processed data \
from the image sensor of a digital camera or image scanner. Raw image files \
are sometimes called digital negatives, as they fulfill the same role as \
film negatives in traditional chemical photography: that is, the negative \
is not directly usable as an image, but has all of the information needed \
to create an image. Storing photographs in a camera's RAW format provides \
for higher dynamic range and allows you to alter settings, such as white \
balance, after the photograph has been taken. Most professional \
photographers use RAW format, because it offers them maximum flexibility. \
The downside is that RAW image files can be very large indeed.</para>  \
<para>My recommendation is clearly to <command>abstain from archiving in \
RAW format</command> (as opposed to shooting in RAW format, which I \
recommend). It has all bad ingredients: many varieties and proprietary \
nature. It is clear that in a few years time you cannot use your old RAW \
files anymore. I have already seen people changing camera, losing their \
color profiles and having great difficulty to treat their old RAW files \
correctly. Better change to DNG format!</para>  \
<para><command>DNG</command> Digital Negative file format is a royalty free \
and open RAW image format designed by Adobe Systems. DNG was a response to \
demand for a unifying camera raw file format. It is based on the TIFF/EP \
format, and mandates use of metadata. A handful of camera manufacturers \
have adopted DNG already, let's hope that the main contenders Canon and \
Nikon will use it one day.</para>


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