koffice/doc/chalk/introduction.docbook

<chapter id="introduction">
<title>Introduction</title>

<sect1 id="introduction-chalk">
<title>What is &chalk;?</title>
<para>
&chalk;, part of &koffice;, can do everything you want with images &mdash; or
it will be able to one day. Everything from photo retouching, image editing,
and last but not least creating original art on your computer as if you were
working with real paint and brushes, pencils, pen and ink. Every day
&chalk; becomes a little better, a little more useful.  We are working on it,
anyway. We, that is, Adrian, Bart, Boudewijn, Casper, Cyrille, Michael and Sven.
It could be you, too &mdash; whether you would like to help with some artwork
for the user interface, cool ideas for the todo, helpful bug reports, usability
reviews or even actual code, you will not be snubbed by us.
</para>
<para>
&chalk; is as much yours as it is ours. It should be fun, innovative, and
experimental &mdash; first and foremost a pleasure to use and to hack on.
</para>
</sect1>

<sect1 id="introduction-keyfeatures">
<title>Key features</title>

<para>The most important features &chalk; currently has to offer, are:</para>
<itemizedlist>

<listitem><para>Plugins: Chalk is extensible through plugins. There are tools,
colorspaces, paint operations, filters and kpart-based user interface plugins.
</para></listitem>

<listitem><para>Scriptable: &chalk; is scriptable in Python and Ruby using
Kross, the cross language scripting engine that originated in Kexi. The
scripting is compatible with PyQt/KDE and Korundum for adding GUI
items, such as dialog boxes.</para></listitem>

<listitem><para>Color models: &chalk; uses lcms for a dependable color
workflow using icc profiles for importing, exporting, selecting paint colors,
printing, cutting and pasting. 8, 16, and 32 bit colorspaces are available
(RGB, CMYK, L*a*b*, ...) and colors can be selected from a color wheel, rgb or
grayscale sliders or with a palette.</para></listitem>

<listitem><para>Editing and viewing: Unlimited undo and redo are available.
You can cut, copy and paste between lagers and images, with conversion through
icc profiles if this is necessary.  OpenGL is supported for display. The view
can be made fullscreen and can be split. Rulers are available, the
image can be zoomed, and for maximizing the workspace all palette windows can
be hidden in one go. Also a histogram palette is available.</para></listitem>

<listitem><para>Images and layers: Layers and entire images can be mirrored,
sheared, rotated and scaled, converted between colorspaces, and layers in
different colorspaces can be merged. An image can be separated into colorspace
channels.</para></listitem>

<listitem><para>Layers: Layers can be added, removed, grouped, locked, made
(in)visible, and re-ordered.  Adjustment layers (layers which perform a filter
function) can be added as well. A layer can be saved as a separate image and
its colorspace can be changed.</para></listitem>

<listitem><para>Tools: Through the innovative paintOp plugin system, all
painting tools (brush, ellipse, line, etc.) can paint aliased, anti-aliased,
erase, airbrush and more.</para></listitem>

<listitem><para>Filters: &chalk; can multithread the operation of some
filters. Filters can be previewed in the filter gallery. Available filters
include color adjustment, sharpen or blur, emboss, raindrops, and
more.</para></listitem>

<listitem><para>Brushes: The GIMP brush shapes can be used, both colored and
grayscale brushes and pipe brushes. Custom brushes can be created, even from
entire layers or images. Colored brushes can also be used as
masks.</para></listitem>

</itemizedlist>

<sect2 id="introduction-keyfeatures-colormanagement">
<title>Color management</title>
<para>
One of the most distinguishing features in &chalk; is its color management.
If you put two screens side to side, you will notice that there is often a lot
of difference in the way they display colors. Even white, especially white, is
often not the same thing at all. On one screen it can be a dirty yellow, on
another screen a sickly bluish. Very seldom is it a creamy milk-white. The same
holds, unfortunately, for scanners, printers and digital cameras. So, if you
want to see the right colors on screen and on paper, being the colors that you
saw when taking your snapshot, you will have to compensate.
</para><para>
&chalk; can do this for you: in &chalk;, a color is (almost) never just a set of
numbers, one for each color channel; it is a set of numbers with information
attached. And that extra information is contained in a profile: your image has a
profile, your scanner has a profile, your camera should have a profile and your
screen has a profile. When passing information from your image to your screen,
the profiles are checked and the correct color is computed. This may cause a
little slowness, now and then, but the result is that you can work with colors,
instead of almost meaningless RGB triplets.
</para><para>
Available colorspaces are: 8 bit/channel RGB, CMYK, grayscale and wet
watercolors, 16 bit/channel RGB, CMYK, grayscale and L*a*b*, <quote>half</quote>
RGB, and 32 bit float RGB (HDR) and LMS.
</para>
</sect2>

<sect2 id="introduction-keyfeatures-imageformats">
<title>Image formats</title>
<para>
&chalk; currently supports the following image formats, both for importing and
exporting, apart from its own: PNG, TIFF, JPEG, Dicom, XCF, PSD, GIF, BMP,
XPM, Targa, RGB, and OpenEXR. Additionally, &chalk; can import 
ICO files. PSD (the Photoshop file format) is only supported up to version 6,
from version 7 on, the Photoshop file format is closed. 
</para><para>
Embedded icc profiles and exif information are preserved on export to
supporting file formats. &chalk;'s native file format stores icc and exif
information.
</para>
</sect2>

</sect1>

<sect1 id="introduction-manual">
<title>About this manual</title>
<para>
We are assuming you have got a good working knowledge of &kde; and of your
operating system. The first chapter will give you a quick tour of &chalk;'s
cool features; the other chapters will expand on that information.
</para>
<note><para>
This manual is not complete. The invitation to join us and help out extends to
the manual, too!
</para></note>
<para>
Should you have any questions, comments or suggestions, please contact the
documentation maintainer at <email>sanderkoning@kde.nl</email>.
</para>
</sect1>

<sect1 id="introduction-maintainer">
<title>About the application maintainer</title>
<para>
Hi! I'm Boudewijn Rempt &mdash; the current maintainer of &chalk;. I was
educated as a linguist, retrained as a database developer, work as a Java
hacker, study theology and I have always liked to paint and sketch a little.
Conspiciously absent in my life have been two important things for a developer
of an image app: mathematics and experience with graphic design. That means that
I am probably not the best person to explain the niceties of using an image
editor or a paint application to you. If you catch me in an error, please don't
hesitate to mail me: <email>boud@valdyas.org</email>.
</para>
</sect1>

</chapter>