1. Open the PDF document in Highlights
Tap the PDF you want to open in the Highlights document browser:
The PDF opens full screen:
2. Select the image you want to extract
This will bring up the selection popover:
2. Tap the image selection tool:
Your image selection is added as a rectangle annotation in the PDF and the image will show up in your notes.
3. Tap inside the image selection
This brings up the annotation popover:
4. Tap the Smart Copy button to copy the image:
Keep in mind that Smart Copy requires Highlights Pro.