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

<sect1 id="introduction-krita">
<title>What is &krita;?</title>

<para> &krita;, 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 &krita; becomes a little
better, a little more useful. We are working on it, anyway. We, that
is, \Bart, Boudewijn, Casper, Cyrille, Lukas, Sven and others. 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. Join us on our mailing list (kimageshop-devel@kde.org)
or on irc &mdash; #koffice@freenode.net. </para>

<para>
&krita; 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 &krita; currently has to offer, are:</para>
<itemizedlist>

<listitem><para>Plugins: &krita; is extensible through plugins. There
are tools, brush engines colorspaces, paint operations, filters, pixel
generators and generic user interface plugins. </para></listitem>

<listitem><para>Scriptable: &krita; 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: &krita; 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. Krita also
supports OpenCTL based colorspace plugins and custom colorspace
plugins, for instance the painterly colorspaces that support mixing
colors in a realistic way.</para></listitem>

<listitem><para>Editing and viewing: Unlimited undo and redo are available.
You can cut, copy and paste between layers 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.  Filter 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. There are clone layers that copy all or
part of a layer to another place in the layer stack. There are vector
layers that allow you to combine your raster images with rich text,
vector graphics and even, though KOffice's plugin system, musical
notation or charts.</para></listitem>

<listitem><para>Masks: masks can be applied to a layer. There are
transparency masks, for masking out a part of a layer, filter masks
that apply a filter to part of a layer, and local selection masks that
constrain editing on a layer to a selection without actually hiding
anything.</para></listitem>

<listitem><para>Brush engines: &krita; comes with a collection of brush
engine plugins, some mimic classical paint tools such as are familiar
to anyone who has used an electronic paint application, others are
programmable, and others again try to mimic traditional media.</para></listitem>

<listitem><para>Tools: there are tools to make it easy to paint lines,
ellipses and other shapes, as well as a full complement of selection
tools. Painting tools can be constrained by guides that make it easy
to paint shapes in a natural-looking way, without being overly
neat.</para></listitem>

<listitem><para>Filters: &krita; can multithread the operation of some
filters. Filters are previewed on the image canvas itself instead of
in a small preview window. Available filters include color adjustment,
sharpen or blur, emboss, raindrops, and more. There is also a category
of plugins called "generators", which can programmatically fill an
area or a layer with pixels.</para></listitem>

<listitem><para>Brushes: 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
grayscale brushes.</para></listitem>

</itemizedlist>

<sect2 id="introduction-keyfeatures-colormanagement">
<title>Color management</title>

<para>
One of the most distinguishing features in &krita; 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> &krita; can do this for you: in &krita;, 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,
16 bit/channel RGB, CMYK, grayscale and L*a*b*, <quote>half</quote>
RGB, and 32 bit float RGB (HDR) and LMS, as well as a set of painterly
colorspaces that compute color mixing using the Kubelka-munk
equations, which, in plain words means that if you mix yellow and blue
you get green, not purple.</para>

</sect2>

<sect2 id="introduction-keyfeatures-imageformats">
<title>Image formats</title>

<para> &krita; currently supports the following image formats, both
for importing and exporting, apart from its own: Raw, PNG, TIFF, JPEG,
Dicom, XCF, PSD, GIF, BMP, XPM, Targa, RGB, and OpenEXR. Additionally,
&krita; 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. &krita;'s native file format stores
icc and exif information. </para>

<para>&krita; supports import and export of not just exif metadata,
but also xmp.</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 &krita;'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>boud@kde.org</email>. </para>

</sect1>

<sect1 id="introduction-maintainer"> 

<title>About the application maintainer</title>

<para> Hi! I'm Boudewijn Rempt &mdash; the current maintainer of
&krita;. I was educated as a linguist, retrained as a database
developer, work as a C++ hacker, and I have always liked to paint and
sketch a little. Conspicuously 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>

