View source for Creating a multi-band GeoTIFF

{{construction}}
: ''This exercise is part of the [[QGIS Tutorial 2013/14]].<br/>In this exercise you will learn how to create images of several bands of satellite data, and how to georeference a raster image.''

==Multiband layers==
To create a multiband image:
# Load the different satellite band layers into [[QGIS]]. For exercise purposes, you can use the landsat-bands from the directory ''geodata/raster/landsat/'' in the [[Course data|course data]]; the layer names start with ''sub'', the band number is indicated by ''B'' and a one- or two-digit number, e.g. ''B1'' or ''B10'' for the first band and ''B1'' or ''B20'' for the second.
# If the processing toolbox is not visible in you [[QGIS]] window yet, select {{mitem|text=Processing --> Toolbox}}. 
# In the processing toolbar, type {{typed|text=merge}} into the search field to find the {{button|text=merge}} tool and open it.
# Click the upper {{button|text=...}} button to select the layers you want to combine. There are different reasonable ways to combine spectral bands, depending on the information you want to obtain:
#* True color (RGB=3,2,1) simulates the natural color.
#* Standard false color (RGB=4,3,2) makes healthy vegetation generally appear red.
#* False color (RGB=5,4,3 or 4,5,3) tends to distinguish different landcover material.
# In the {{button|text=Layer stack}} pulldown-menu, select {{button|text=Yes}}. 
# Click the bottom {{button|text=...}} button to select directory and file name to save the result. You can skip this step if you only want to save the result temporarily.
# Check the box {{button|text=Open output file after running algorithm}} (if not checked per default) and click {{button|text=Run}}. The resulting map should be added to the [[TOC]] automatically after the algorithm has finished, under the name ''Output layer''.
# If necessary, you can rearrange the bands by opening the layer [[Exercise 01: First steps in QGIS|properties]] and selecting the {{button|text=Style}} tab. Adjust the bands as you see fit and confirm with {{button|text=Apply}} or {{button|text=OK}}.
#* For some color composites, (e.g. true color composites), the image may be enhanced by selecting {{button|text=Stretch to MinMax}} from the {{button|text=Contrast enhancement}} menu and selecting the {{button|text=Mean +/- standard deviation x}} radio button. After adjusting the standard deviation factor (a value between 1 and 2 should do), click {{button|text=Load}} and confirm with {{button|text=Apply}} or {{button|text=OK}}.

[[Image:RemSens_Exercise03_1.png|thumb|left|width=600px|The ''merge'' dialogue in [[QGIS]] 2.0]]
[[Image:RemSens_Exercise03_2.png|thumb|left|width=600px|The ''properties'' dialogue for a multiband raster layer in [[QGIS]] 2.0]]