edlp_d8/core/modules/system/migrations/system_image_gd.yml

id: system_image_gd
label: Image quality configuration
migration_tags:
  - Drupal 6
  - Drupal 7
  - Configuration
source:
  plugin: variable
  variables:
    - image_jpeg_quality
  source_module: system
process:
  jpeg_quality: image_jpeg_quality
destination:
  plugin: config
  config_name: system.image.gd