There are so many tools that can download images from various websites like Reddit but all of these tools download these images blindly. They do not allow you to filter the images that you wish to download. If you want more control on the type of images that you want to download, then perhaps you may want to use the open-source ImageDownloader.
The ImageDownloader program is designed to work in Windows that has .NET framework 4.5 installed. And it allows you to filter the images based on their resolutions. This means that you can specify a maximum and minimum resolution for the images before it begins to download them in your computer. The program supports Reddit and Imgur as the image sources. In addition, you can also use a local folder as the images source if you want to copy the images of a certain resolution to the destination folder.
If you want to download images from a particular sub-reddit then you have to choose the Reddit tab and then enter the sub-reddit name in the space provided for. The sub-reddit is the whatever comes after /r/ in the reddit URL. For example, in the case of https://www.reddit.com/r/wallpapers/, the sub-reddit is wallpapers.
After this you can specify the destination folder, the resolution filters (minimum and maximum dimensions), aspect ratio, whether the posts are to be pulled from all the time or only for a specific duration of time, whether to include the albums and how many images are to be pulled in one go and more. Finally clicking on the Download button will start the downloading of the images.
With Imgur it is a little different, because the Imgur API does not allow more than 500 requests per day based on your IP address and 12500 requests per day based on your client. Everything else seems very similar to the Reddit section.
Verdict: ImageDownloader can fetch all those cool wallpapers from Reddit that you wanted to use on your new computer so much. It can filter the images based on their resolutions, aspect ratio and other factors.
You can download ImageDownloader from https://github.com/Jameak/ImageDownloader/releases.