From TIKA-3348 (https://issues.apache.org/jira/browse/TIKA-3348?page=com.atlassian.jira.plugin.system.issuetabpanels%3Aall-tabpanel)  there's an example PDF of variously arranged images in a document and this Note shows how the current Tika does extract all the images but this takes a number of passes through Tika.