Images are in the form:
<img src="/sites/drupalarchitect/files/inline-images/Drupal%20embedded%20images_0.png" data-entity-uuid="d9876b0f-e681-4ea7-b253-686749238478" data-entity-type="file">
Change record: https://www.drupal.org/node/2381651
Migrate plus plugins: https://www.drupal.org/node/3256493
(See dom_select) for extracting img tags.
Media Migration
Media Migrate module seems to work for D6/7 migrations.
https://www.drupal.org/project/media_migration
https://www.drupal.org/project/media_migration/issues/3223771
Patch for body images: https://www.drupal.org/project/media_migration/issues/3223771
Allow use of ContentEntity (for Drupal 8/9/10 source): https://www.drupal.org/project/media_migration/issues/3372102
Migrate File To Media
https://www.drupal.org/project/migrate_file_to_media
Won't work for body images: https://www.drupal.org/project/migrate_file_to_media/issues/3066044
https://www.drupal.org/project/media_migration/issues/3311013
Migrate Media Handler
https://www.drupal.org/project/migrate_media_handler
DomInlineImageHandler: https://www.drupal.org/project/media_migration
Examples: https://git.drupalcode.org/project/migrate_media_handler
Automated Drupal 10 compatibility fixes: https://www.drupal.org/project/migrate_media_handler/issues/3288626
Upgrade compatibility with migrate tools: https://www.drupal.org/project/migrate_media_handler/issues/3312629
Create option to migrate D8/9 file/image field data to media fields: https://www.drupal.org/project/migrate_media_handler/issues/3225418
Useful patch for above issue: https://www.drupal.org/files/issues/2021-11-02/file-to-media-batch-3225418-3.patch
Migrate File Singularity
Sandbox module
https://www.drupal.org/sandbox/srjosh/3078435
Image To Media Filters
Fixes legacy tags:
[img_assist|nid=9491|title=|desc=|link=none|align=right|width=100|height=37]
[acidfree:9491 align=left size=80x163]
[image:9491]https://www.drupal.org/project/image_to_media_filters
Atom Migrate
Migrate atom feed to paragraphs/media.
Migrate Body
Dev code only, but may have something that helps.
https://www.drupal.org/project/migrate_body
BodyTextContentMigration: https://git.drupalcode.org/project/migrate_body/-/blob/8.x-1.x/src/Plugin/migrate/process/BodyTextContentMigration.php
Migrate HTML To Paragraphs
https://www.drupal.org/project/migrate_html_to_paragraphs
WYSIWYG image support: https://www.drupal.org/project/migrate_html_to_paragraphs/issues/3038351
<p>[[{"fid":"64293","attributes":{"alt":"Alt of the image","title":"Title of the image","data-delta":"1"}}]]</p>
Migrate Tools
ID list issue: https://www.drupal.org/project/migrate_tools/issues/3228964
Source ID optimize: https://www.drupal.org/project/migrate_tools/issues/3041072
Migrate (Core)
[meta] Migration to media: https://www.drupal.org/project/drupal/issues/2930514
Provide an optional migration path for sites using files/images to media entities: https://www.drupal.org/project/drupal/issues/2885002
Determine an upgrade path from CKEditor image button to media library: https://www.drupal.org/project/drupal/issues/3073901
Add d8 media migration: https://www.drupal.org/project/drupal/issues/2835825
ContentEntity migration source doesn't consider the migration map: https://www.drupal.org/project/drupal/issues/3188914
Other core media issues
Media initiative: Roadmap: https://www.drupal.org/project/ideas/issues/2825215
[META] Once media is enabled, having the File, Image and Media reference fields all listed is confusing: https://www.drupal.org/project/drupal/issues/2885002
Allow image style to be selected in Text Editor's image dialog: https://www.drupal.org/project/drupal/issues/2061377
Add a selection overview to the media library widget modal: https://www.drupal.org/project/drupal/issues/3023809
Document the difference between File, Image, and Media fields: https://www.drupal.org/project/drupal/issues/2934885
Media Library's embed modal is almost unusable with less than 600px browser viewport width: https://www.drupal.org/project/drupal/issues/3102011