The documents of Google Docs that incorporate an image present some complication to extract the image in order to be able to use it, but there is some method to be able to achieve this.
One of the most practical and simple methods to download images from a Google Docs document can be by means of the Google Keep tool
There are third-party applications that provide this function but there are other ways, some of them quite simple.
-Download the HTML file: This may be the easiest. Just open the document from Google Docs and follow the path “File – Download – Web Page”, which will download to your computer a file (compressed in .zip) of the HTML. In the Downloads folder of the computer will appear a folder with the name of the document containing everything integrated in the HTML, where there will be a subfolder with all the images contained in the document.
-Publish to the Internet: This modality involves some additional detour over the previous method. Follow the path “File – Share – Publish to the web” and you get a version of the resulting web page whose link can be copied to a new browser tab and, when loaded, will allow you to resort to the usual method when surfing the Internet of placing the mouse pointer over the image you want to download and right-clicking on it.
-Save from Keep: This method is perhaps the one that combines a smaller number of users who may know about it with greater ease of use. It is based on Keep, Google’s notes and reminders organizer, and offers the possibility to directly manage the destination and use of the image to be saved from a Google Docs document.
It is enough to access the referred document from Google Docs, place yourself over the image you want to download and when clicking on it with the right mouse button select “View more options” in the pop-up menu, where you will select “Save to Keep”.
Once the image has been stored in Keep from this application it can be saved to the computer using the traditional method (right mouse button + save). Later the image can be deleted from Keep or kept as a note or reminder for other uses.