Nothing, just install an use it !

All configuration is static in ext_typoscript_setup.txt , no PHP ... only a small bit Typoscript !

Content of  ext_typoscript_setup.txt:

# Setup: Image multi pagelink

mk_imagemultilink < tt_content.image.20.1.imageLinkWrap

tt_content.image.20.1.imageLinkWrap  >

mk_imagemultilink {

# The original conf

#     enable.ifEmpty.field = image_link

#     typolink.parameter.field = image_link

# Add new conf

# Prirority is : 1. Standardfield "image_link" and  if emty then "tx_mkimagemultilink_targets"

#

enable.ifEmpty.field = image_link // tx_mkimagemultilink_targets

typolink.parameter.field = image_link // tx_mkimagemultilink_targets

        typolink.parameter.listNum.stdWrap.data = register : IMAGE_NUM

}

tt_content.image.20.1.imageLinkWrap < mk_imagemultilink

mk_imagemultilink >

###############################################################

# same for content element textpic (text with image),

# if was different configured with typoscript

mk_imagemultilink < tt_content.textpic.20.1.imageLinkWrap

tt_content.textpic.20.1.imageLinkWrap  >

mk_imagemultilink {

# The original conf

#     enable.ifEmpty.field = image_link

#     typolink.parameter.field = image_link

# Add new conf

# Prirority is : 1. Standardfield "image_link" and  if emty then "tx_mkimagemultilink_targets"

#

enable.ifEmpty.field = image_link // tx_mkimagemultilink_targets

typolink.parameter.field = image_link // tx_mkimagemultilink_targets

typolink.parameter.listNum.stdWrap.data = register : IMAGE_NUM

}

tt_content.textpic.20.1.imageLinkWrap < mk_imagemultilink