Sometimes we want or need to add images to our custom QGIS plugins, here’s how you do it.
It’s highly suggested that you use images that are already in the size that you want them to be in your plugin
Make sure that resources.qrc is located in the root folder of your plugin.
<RCC> <qresource prefix="plugins/name-of-plugin" > <file>location/of/file1.png</file> <file>location/of/file2.png</file> </qresource> </RCC>
Go to the Resource Browser located at the bottom right part of Qt Designer and click Edit Resources.
Click Open Resource File and select the resources.qrc file you created.
If there are no errors, you should be able to see the resources(images) that you added in the resources.qrc file. Click OK.
Add a Label widget. Delete the text.
On the Property Editor, go to QLabel -> pixmap and select Select Resource.
Select the image you want to add and edit the size of the Label on your GUI.
pyrcc resources.qrc -o resources_rc.py
If you want to know why we compile it to resources_rc.py, check here
sudo python /usr/lib/python2.7/dist-packages/qgis/PyQt/uic/pyuic.py name-of-file.ui -o name-of-file.py
After this, you should be able to see the images you added in your GUI the next time you run your plugin in QGIS.