The option to Export Images can be found in the Page Tab: 

First, you need to choose the pages you want to export images from.  

You can click on the three dots in the right upper corner to show more options.

 There you can choose the format for your image files. 

You can click on the Browse... option to choose the save location for your images.

Deselect the check box next to Open folder with image files after export if you do not want this folder to open after extraction. 

Click on Export to begin.  

The files will be named based on which page they were on, and their order on the page. 

Example: 

Page_1_Image_1 
Page_1_Image_2 
Page_4_Image_3