Batch reprojection

Layers can be reprojected in a batch operation without having to enter parameters individually on the Save as dialog. This recipe shows you how to reproject a set of layers to a different CRS using an algorithm from the Processing Toolbox menu. You will see how to reproject all the files accompanying the Davis_DBO_centerline.shp file that you reprojected in the Reprojecting a layer recipe.

How to do it…

  1. In the filter box of the Processing Toolbox menu, type Reproject to filter the list of available algorithms. Locate the Reproject layer algorithm, right-click on it, and select Execute as batch process. The batch processing interface will be shown, as follows:
    How to do it…
  2. In the upper cell of the Input layer column, click on the ... button and select Select from filesystem. A file selector dialog will appear. Select the content of the davis folder in the dataset and add the files to the table.
  3. In the first cell in the Target CRS column, click on the ... button. A CRS selector will appear. Select the EPSG:26911 CRS, as you did in a previous recipe when converting a single layer. Copy the value to the rest of rows in the column by double-clicking on the column header.
  4. Set all the values in the Reprojected layer column. Select a file in the first cell, and then use the Fill with parameter value option to automatically fill the rest of rows.
  5. Once the table is complete, click on Run to reproject the layers.

How it works…

The reprojection algorithm is a part of the Processing framework, so you can select the output format by changing the output file extension. You can use this to not only reproject a set of input layers but to also convert their format, all in a single step.

There's more…

Raster layers can also be reprojected with another algorithm from the Processing Toolbox menu named Warp (reproject). These inputs are rather similar to the ones in the reprojection tool for vector layers with some additional parameters that are specific to raster layers. Select the algorithm, right-click on it, and select Execute as batch process to run it and convert a set of raster layers.

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