I assume the image is coming from a recordset and is displayed in a repeat region?
create a link around the image that will pass the item ID as query string variable using the ID column from the products recordset:
<a href="Products_Detail.php?ProductID=<?php echo($row_RecordsetName['IDColumn']); ?>"><image tag></a>
then on the products detail page, create a recordset that filters the IDCulumn on the ProductID querystring variable.