# [QGIS Commit] r9954 - docs/trunk/english_us/user_guide

svn_qgis at osgeo.org svn_qgis at osgeo.org
Thu Jan 8 17:01:52 EST 2009

Author: timlinux
Date: 2009-01-08 17:01:52 -0500 (Thu, 08 Jan 2009)
New Revision: 9954

Modified:
docs/trunk/english_us/user_guide/working_with_raster.tex
Log:

Modified: docs/trunk/english_us/user_guide/working_with_raster.tex
===================================================================
--- docs/trunk/english_us/user_guide/working_with_raster.tex	2009-01-08 21:58:05 UTC (rev 9953)
+++ docs/trunk/english_us/user_guide/working_with_raster.tex	2009-01-08 22:01:52 UTC (rev 9954)
@@ -23,8 +23,9 @@
\end{itemize}

Because the raster implementation in QGIS is based on the GDAL library, other
-raster formats implemented in GDAL are also likely to work, but have not yet
-been tested. You find more details in Appendix \ref{appdx_gdal}
+raster formats implemented in GDAL are also likely to work - if in doubt try
+to open a sample and see if it is supported. You find more details about GDAL
+supported formats in Appendix \ref{appdx_gdal}
\index{raster layers!GDAL implementation} or at
\url{http://www.gdal.org/formats_list.html}. If you want to load GRASS raster
@@ -40,7 +41,7 @@
matrix.

Unlike vector data, raster data typically do not have an associated database
-record for each cell. They are geocoded by it's pixel resolution and the x/y
+record for each cell. They are geocoded by its pixel resolution and the x/y
coordinate of a corner pixel of the raster layer. This allows QGIS to position
the cata correctly in the map canvas.

@@ -56,7 +57,7 @@
\keystroke{Control} or \keystroke{Shift} key and clicking on multiple items

-Once a raster layer is loaded in the map legend you can click on the name with the
+Once a raster layer is loaded in the map legend you can click on the layer name with the
right mouse button to select and activate layer specific features or to open
a dialog to set raster properties for the layer.

@@ -102,20 +103,24 @@

\subsubsection{Symbology Tab}\label{label_sombology}

-QGIS can render two different types of rasterlayers:\index{raster layers!supported channels}
+QGIS can render raster layers in two different ways :\index{raster layers!supported channels}

\begin{itemize}
-\item Single band gray
-\item Three band color
+\item Single band - one band of the image will be rendered as gray or in
+pseudocolors.
+\item Three band color - three bands from the image will be rendered, each
+band representing the red, green or blue component that will be used to create
+a color image.
\end{itemize}

-Within both rendertypes you can invert the color using the checkbox
-\checkbox{Invert color map}.
+Within both rendertypes you can invert the color output using the
+\checkbox{Invert color map} checkbox.

-\minisec{Single band gray}
+\minisec{Single Band Rendering}

This selection offers you two possibilites to choose. At first you can
-select which band you like to use for rendering.
+select which band you like to use for rendering (if the dataset has more than
+one band).

The second option offers a selection of available colortables for rendering.

@@ -147,9 +152,8 @@
standard RGB-order to something else.

Also scaling of colors are available.
-Note that customizing min and max values for each band is only available
-if your dataset has three bands or more.

+
\begin{Tip}\caption{\textsc{Viewing a Single Band of a Multiband Raster}}
\qgistip{If you want to view a single band (for example Red) of a multiband
image, you might think you would set the Green and Blue bands to Not
@@ -164,17 +168,17 @@
levels.\index{raster layers!transparency} Use the transparency slider to indicate to
what extent the underlying layers (if any) should be visible though the
current raster layer.
-This is very usefull, if
+This is very useful, if
you like to overlay more than one rasterlayer, e.g. a shaded relief-map
overlayed by a classified rastermap. This will make the look of the map
-more plastique.
+more three dimensional.

Additionally you can enter a rastervalue, which should be treated as
{\em NODATA}.

An even more flexible way to customize the transparency can be done in the