How can I save the background image of a web page in Opera?
Right-click the web page and select Inspect Element. Press the icon to dock the page in the main window. Next, press the Resources tab. To expand the Frames list use icon. Expand the folder Images Select the background image from the list and once it is opening in the right window, Right-click on the image and select Open image in new tab . In the new tab , Right-click the image and select Save image as to save the image.
The process is the same like it was explained to the related question. Right click an empty area on the background of the page and then click Inspect Element. Follow the guide on the image for additional information: