This information will explore how to download all images from a subreddit or images from posts you upvoted, added to saved, or from some other available lists on your account.
If you would like to download all images from a subreddit. Here is simple method using KellyC Image Downloader extension. I'm also using Reddit (my profile for direct messages) and you can share feedback, addition instructions or some help there by DM or on extension subreddit
Using the steps in this tutorial, you can download any number of images in full size or previews only from a specific subreddit or reddit user or your collections (upvoted, downvoted, etc)
1. Install KellyC Image Downloader extension
2. Go to on any reddit page that contains needed images (subreddit, saved, upvoted posts, etc) and click on extension icon
3. Press "Record" button - number of captured images will appear on bottom of page. Scroll or navigate through needed pages - all images during record will be captured, you can later filter unnecessary images before actual download
4. When all needed pages will be visited or all required information is scrolled - click on extension icon again an click "Stop record" -> "Download record"
5. If you need to get full size original images instead of previews then press "Load related links"
6. For download collected images press "Download" -> "Start download"
Video example
Also here is common example for reddit to capture all data from upvoted section on user page. Another sections, subreddits data can be downloaded in the same way.
Source code of reddit filter implementation for extension can be found here