An image processing device is provided. The device comprises processing means configured to determine a first zone from an image associated with the user wherein the first zone is associated with one or more features characterising the user and wherein the first zone is associated with a first set of sample values; determine a second zone from a further image associated with the user wherein the second zone is associated with a second set of sample values wherein a location of at least some of the second set of sample values are different from a location of the first set of sample values; and determine a characteristic value from the second zone based on sample values associated with the second zone.