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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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