[Digikam-devel] extragear/graphics/doc/showfoto
Gilles Caulier
caulier.gilles at free.fr
Wed Sep 14 16:13:46 BST 2005
SVN commit 460634 by cgilles:
Showfoto handbook : Update "Image File formats Support" section.
IMPORTANT : Checking English words request.
CCMAIL: digikam-devel at kde.org
M +51 -9 index.docbook
--- trunk/extragear/graphics/doc/showfoto/index.docbook #460633:460634
@@ -138,19 +138,61 @@
<sect2>
<title>Still Photograph Formats</title>
+
+ <sect3>
+ <title>Introduction</title>
+
+ <para>
+ Almost all digital cameras store photographs in one of two formats: JPEG or TIFF. Many cameras enable you to select which of these formats to use. A full description of these formats can be found at the <ulink url="http://en.wikipedia.org/wiki/Graphics_file_format">Wikipedia</ulink>. &showfoto; supports both of these formats.
+ </para>
+
+ </sect3>
- <para>
- Almost all digital cameras store photographs in one of two formats: JPEG or TIFF. Many cameras enable you to select which of these formats to use. JPEG is a compressed format, that trades some of the image quality to keep file sizes small. TIFF is not a compressed format, it maintains higher image quality but at the expense of much larger file sizes. A full description of these formats can be found at the <ulink url="http://en.wikipedia.org/wiki/Graphics_file_format">Wikipedia</ulink>. &showfoto; supports both of these formats.
- </para>
+ <sect3>
+ <title>JPEG</title>
+ <para>
+ JPEG is a compressed format, that trades some of the image quality to keep file sizes small. In fact, most cameras save their images in this format unless you specify otherwise. A JPEG image is stored using lossy compression and you can vary the amount of compression. This allows you to choose between lower compression and higher image quality or greater compression and poorer quality. The only reason to choose higher compression is because it creates smaller file so you can store more images, and it's easier to send them by e-mail, or post them on the Web. Most cameras give you two or three choices equivalent to good, better, best although the names vary.
+ </para>
+
+ </sect3>
- <para>
- PNG is an image format that was developed as a replacement for a number of older, in the 1990's widely used, image file formats. It is a lossless format like TIFF but it is much more compact and can save you disk space. Although your camera is unlikely to support PNG, some people like to convert their photographs to PNG as soon as they get them on their computer. Unlike JPEG, PNG images do not loose quality every time you re-encode them after alteration. For more information about the PNG format see the <ulink url="http://www.libpng.org/pub/png/">PNG homepage</ulink>.
- </para>
+ <sect3>
+ <title>TIFF</title>
+ <para>
+ TIFF has been widely accepted and widely supported as an image format. Commonly, TIFF may be stored by the camera in uncompressed form or using lossless compression algorithm (Adobe Deflate). It maintains higher image quality but at the expense of much larger file sizes. Some cameras let you save your images in this format and it is a popular format because of its lossless compression algorithm. 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 programs.
+ </para>
+
+ </sect3>
+ <sect3>
+ <title>PNG</title>
+ <para>
+ PNG is an image format that was developed as a replacement for a number of older, in the 1990's widely used, image file formats. It is a lossless format like TIFF but it is much more compact and saves disk space. Although your camera is unlikely to support PNG, some people like to convert their photographs to PNG as soon as they get them on their computer. Unlike JPEG, PNG images do not loose quality every time you re-encode them after modification. &showfoto; fully supports PNG images.
+ </para>
+
+ <para>
+ PNG is an extensible file format for the lossless, portable, well-compressed storage of raster images. PNG provides a patent-free replacement for GIF and can also replace many common uses of TIFF. PNG is designed to work well in online viewing applications, such as the World Wide Web, so it is fully streamable with a progressive display option. Also, PNG can store gamma and chromaticity data for improved color matching on heterogeneous platforms. PNG supports 8 and 16 bits / colors /pixels depth. It's the perfect file format to archive your photographs. For more information about the PNG format see the <ulink url="http://www.libpng.org/pub/png/">PNG homepage</ulink>.
+ </para>
+
+ </sect3>
+
+ <sect3>
+ <title>CCD RAW</title>
+
+ <para>
+ Some, typically more expensive, cameras allow you to store images in RAW format. RAW format is not really an image standard at all. It is different for every make of camera. RAW format images contain all the data that is taken directly from the camera's image sensor before the software in the camera applies things like white balance, sharpening etc. Storing photographs in a camera's RAW format 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. If you want to learn more about RAW image format visit the very helpful guides <ulink url="http://www.luminous-landscape.com/tutorials/understanding-series/u-raw-files.shtml"> The Luminous Landscape</ulink> and <ulink url="http://www.cambridgeincolour.com/tutorials/RAW-file-format.htm"> Cambridge in Colour</ulink>.
+ </para>
+
+ <para><note>
+ &showfoto; do not yet support to load RAW image files. You can convert RAW format images into JPEG or TIFF with digiKam using the <ulink url="help:/kipi-plugins/rawconverter.html">RAW Image Converter plugin</ulink>.
+ </note></para>
+
+ </sect3>
+
</sect2>
<sect2>
- <title>How &showfoto; Supports File Formats</title>
+ <title>How &digikam; Supports File Formats</title>
<para>
&showfoto; relies on a number of libraries and support packages to load and save image formats. Which image formats are available will depend on the availability of these libraries on your system and, in some cases, on the way that those libraries have been compiled. On most distributions you will find that a wide range of image formats are viewable within &showfoto;.
@@ -2470,11 +2512,11 @@
<title>How to Obtain &showfoto;</title>
<para>
-The website for &showfoto; is at <ulink url="http://www.digikam.org">http://www.digikam.org</ulink>. Please check it regularly to get the latest news about &showfoto;. &showfoto; can be obtained in binary and source format from <ulink url="http://sourceforge.net/project/showfiles.php?group_id=42641">http://sourceforge.net/project/showfiles.php?group_id=42641</ulink>.
+&showfoto; is a part of <emphasis>digiKam project</emphasis> and the website is at <ulink url="http://www.digikam.org">http://www.digikam.org</ulink>. Please check it regularly to get the latest news about &showfoto;. &showfoto; can be obtained in binary and source format from <ulink url="http://sourceforge.net/project/showfiles.php?group_id=42641">http://sourceforge.net/project/showfiles.php?group_id=42641</ulink>.
</para>
<para>
-Also you can checkout the <emphasis>digikam</emphasis> and <emphasis>kipi</emphasis> source code modules
+Also you can checkout the <emphasis>digiKam</emphasis> source code modules
from KDE Extragear SVN repository like this:
<screen width="40">
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