Good news! Most of these images have been successfully reuploaded to SE Imgur.
This is thanks to Glorfindel’s efforts — you can read more details on their Meta SE post at: Imgur TOS change on May 15th 2023 could cause the loss of thousands of Stack Exchange images!
Note that Glorfindel’s script has not fixed any posts yet; it has only reuploaded images. Follow their answer on the relevant Meta SE post for updates on whether it will fix the posts. Based on what Glorfindel wrote, it seems that it would need the help of SE staff to mass edit all the affected posts in the SE network. The Meta SE post has been marked status-review, so the affected posts are likely to be fixed soon. Therefore, there’s no need to manually fix posts or reupload the associated images that have already been uploaded by Glorfindel’s script.
Some media could not be reuploaded to SE Imgur by Glorfindel's script
…because they exceeded the 2 MiB file size limit, were in unsupported formats (GIFV, MP4, WEBP), or have been deleted from Imgur. For SF&F SE, there are only 30 failed reuploads to SE Imgur (2 in the child meta), so we should focus our efforts on editing those images (or looking for copies/alternatives if they've been deleted) to fit SE Imgur's requirements.
List of failed reuploads
These are the failed reuploads at the time Glorfindel's script ran in SF&F SE (Image URLs and failure info are from the results of Glorfindel’s script). The list excludes fixed media — media that have been converted to 2 MiB or less, converted to an SE Imgur–compatible format, or for which a replacement has been found (if deleted), and then reuploaded and edited into their associated posts.
As of 2023-05-08, 29 out of the 32 media have been fixed. (Good work, everyone!)
If you have fixed the media and their associated posts, please remove their respective entries in the table. If there's an issue preventing the fixing of the associated posts, please note it in the "Notes" column of the table. (This post has been made a Community wiki post, so anyone can edit it.)
Some notes on converting:
• For quick conversion, you can use XnShell (Windows only): it adds a few neat Shell Extension (right-click file menu) options.
• JPGs > 2 MiB can be made ≤ 2 MiB by saving them at a lower quality. Some image editing software, such as Irfanview, have a 'set file size' functionality. Setting it at 2048 KiB (= 2 MiB) should work.
• PNGs > 2 MiB can usually be made ≤ 2 MiB by saving them to JPG. Setting quality = 95 usually works.
• Imgur GIFV videos also have a GIF version in a similar URL pattern. E.g., https://i.imgur.com/example.gifv → https://i.imgur.com/example.gif
• GIFs > 2 MiB are a bit trickier to edit. Using a GIF optimizer such as this one, it may be possible to lessen its filesize to ≤ 2 MiB by doing one or more of the following: resizing it to have lower resolution (SE only shows 650px max width on embedded images), color reduction to reduce colors to 128, lossy GIF compression, cutting its frames in half by removing every 2nd frame then slowing it down to 50% to get back to previous speed.
• Another alternative is to archive the post using services such as: Internet Archive Wayback Machine and archive.today, so that the images in it can be edited back later. Note that this will only archive the image if it is embedded into the post. If it is linked but not embedded into the post you will need to archive the original Imgur URL, e.g.,