Getting extent of layer in QGIS

Question

Is there a way to get the extent (bbox) of a vector layer in QGIS?

I see that I can update the extent, but I am looking for the actual coordinates of the extent.

score 22 · Accepted Answer · edited Aug 28 '21 at 07:52

22

The layer extents are available in the Layer Properties | Metadata section | Extent.

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edited Aug 28 '21 at 07:52

Taras

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answered Feb 03 '14 at 17:56

underdark

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score 13 · Answer 2 · edited Aug 28 '21 at 07:48

13

To get a bounding box in QGIS as a new vector layer use the "Extract layer extent":
Vector -> Research Tools -> Extract layer extent

enter image description here

edited Aug 28 '21 at 07:48

Taras

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answered Feb 03 '14 at 17:06

Curlew

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I don't really want to create a new file. I am only interested in the four coordinates. – ustroetz Feb 03 '14 at 17:08
You could just use extract the nodes of the newly created polgygon and use the Export/Add geometry columns tool to get the corner coordinates. Put everything into a Processing model and it runs in no time...? – Curlew Feb 03 '14 at 17:15
Note: This works for raster layers too – prusswan Jun 25 '19 at 06:34

score 2 · Answer 3 · edited Aug 28 '21 at 10:35

2

PostGIS has the ST_Extent() function which generates a bounding box for you. So my approach would be to export the layer to a database. if you want id, name, geom, bounding box just do

select id, name, geom, ST_Extent(geom)
from your_table group by id

edited Aug 28 '21 at 10:35

Taras

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answered May 14 '19 at 01:53

Bett Doug

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score 2 · Answer 4 · answered Aug 28 '21 at 03:00

From the (right-click) context menu of the desired layer, choose Export => Save Feature As...

In the dialog that appears, you can ignore all inputs and just scroll down to the Extent section and enable the checkbox.

So for a standard bbox array of [minx,miny,maxx,maxy] your values would be [west,south,east,north].

score 2 · Answer 5 · answered Aug 28 '21 at 08:26

There are several possibilities by means of the PyQGIS

Using the .boundingBoxOfSelected() method

layer = QgsProject.instance().mapLayersByName('test')[0]
layer.selectAll()
extent = layer.boundingBoxOfSelected()
print(extent)
layer.removeSelection()

Using the .extent() method

layer = QgsProject.instance().mapLayersByName('test')[0]
extent = layer.extent()
print(extent)

In both cases, the result will end up in a form of:

<QgsRectangle: 435177.19075885589700192 5645765.28368342109024525, 435464.76195503829512745 5645985.34679672587662935>

To get a more visually pleasing result, please extend the code with an approach mentioned in this answer

xmin = extent.xMinimum()
xmax = extent.xMaximum()
ymin = extent.yMinimum()
ymax = extent.yMaximum()
print('XMin:{0}, XMax:{1}, YMin:{2}, YMax:{3}'.format(xmin, xmax, ymin, ymax))

this will lead in

XMin:435177.1907588559, XMax:435464.7619550383, YMin:5645765.283683421, YMax:5645985.346796726

score 2 · Answer 6 · answered Aug 28 '21 at 08:47

It is also possible to get the extent within the Field Calculator by means of the layer_property() function and its extent parameter, and a bunch of: x_min, x_max, y_min, and y_max.

x_min(layer_property('test', 'extent')) || ' ' || x_max(layer_property('test', 'extent')) || ' ' || y_min(layer_property('test', 'extent')) || ' ' || y_max(layer_property('test', 'extent'))

This expression will lead to this result:

435177.1907588559 435464.7619550383 5645765.283683421 5645985.346796726

score 0 · Answer 7 · answered Aug 28 '21 at 10:59

0

Also similar to @underdark's answer, you may see under the Information | Information from provider

The extent is provided in the following order: xmin,ymin : xmax,ymax

answered Aug 28 '21 at 10:59

Taras

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Getting extent of layer in QGIS

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