Data type conversion
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(Difference between revisions)
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# Click {{button|text=Open}}, and the raster layer appears on the QGIS canvas. | # Click {{button|text=Open}}, and the raster layer appears on the QGIS canvas. | ||
# In the processing toolbar, type {{typed|text=Rescale}} into the search field to find the {{button|text=Orfeo Toolbox --> Image Manipulation --> Rescale Image)}} tool. Open it with a double click. | # In the processing toolbar, type {{typed|text=Rescale}} into the search field to find the {{button|text=Orfeo Toolbox --> Image Manipulation --> Rescale Image)}} tool. Open it with a double click. | ||
− | Specify a new output file name as shown in the screenshot | + | Specify a new output file name as shown in the screenshot. |
[[File:Qgis_rescale.png|400px]] | [[File:Qgis_rescale.png|400px]] | ||
The output Image raster is now recoded to correct eight bit data range but the data type is now '''Float32 - Thirty two bit floating point'' | The output Image raster is now recoded to correct eight bit data range but the data type is now '''Float32 - Thirty two bit floating point'' |
Revision as of 13:26, 23 October 2017
We may change the data type (or radiometric resolution) of a raster layer.
- Click the Add raster layer and select a single band file C:/OSGeo4W64/geodata/raster/s2/Subset_S2A_MSIL2A_20170619T_B03.tif. This is the spectral green band with the data type UInt16 - Sixteen bit unsigned integer Unsigned Integer with the value range 0 to 65535 (Check the Raster metadata). We would like to convert the raster to data type Byte - eight bit unsigned integer, value range 0 to 255.
- Click Open, and the raster layer appears on the QGIS canvas.
- In the processing toolbar, type Rescale into the search field to find the Orfeo Toolbox --> Image Manipulation --> Rescale Image) tool. Open it with a double click.
Specify a new output file name as shown in the screenshot. The output Image raster is now recoded to correct eight bit data range but the data type is now 'Float32 - Thirty two bit floating point
- In the processing toolbar, type Convert data into the search field to find the SAGA --> Raster tools --> Convert data storage) tool. Open it with a double click.
Specify
- Data storage type: [1] unsigned 1 byte integer
- Converted grid: a new output file name.