An interfacing apparatus for an event sensor, said sensor comprising a plurality of event generation elements, the apparatus comprising: a grouping unit configured to generate a plurality of groups of event generation elements, wherein the groups are arranged in a matrix having rows and columns and each goup comprises a plurality of event generation elements, said grouping unit comprising: for each row of groups, a respective first grouping unit for generating a first group event signal by grouping first event signals corresponding to the event generation elements that are arranged in the groups in said row; for each column of groups, a respective second grouping unit for generating a second group event signal by grouping second event signals corresponding to the event generation elements that are arranged in the groups in said column, each first event signal and second event signal being generated in response to detecting an event by a respective event generation element; an interface configured to output an address and data of the group in which the event occurs, based on the generated first and second group event signals, wherein the interface comprises: a first arbiter configured to select one of at least one first group event signal, in response to the at least one first group event signal; and a second arbiter configured to select one of at least one second group event signal, in response to the at least one second group event signal corresponding to the selected first group event signal; wherein the first arbiter is configured to output a first address corresponding to the row for which the selected first group event signal was generated, wherein the second arbiter is configured to output a second address corresponding to the column for which the selected second group event signal was generated, and wherein the interface further comprises a data output unit configured to output data of the event generation elements arranged in the group that corresponds to the first address and the second address, and wherein the event is to occur when a change of light is sensed for a pixel corresponding to an event generation element of the group. a grouping unit configured to generate a plurality of groups of event generation elements, wherein the groups are arranged in a matrix having rows and columns and each goup comprises a plurality of event generation elements, said grouping unit comprising: for each row of groups, a respective first grouping unit for generating a first group event signal by grouping first event signals corresponding to the event generation elements that are arranged in the groups in said row; for each column of groups, a respective second grouping unit for generating a second group event signal by grouping second event signals corresponding to the event generation elements that are arranged in the groups in said column, each first event signal and second event signal being generated in response to detecting an event by a respective event generation element; for each row of groups, a respective first grouping unit for generating a first group event signal by grouping first event signals corresponding to the event generation elements that are arranged in the groups in said row; for each column of groups, a respective second grouping unit for generating a second group event signal by grouping second event signals corresponding to the event generation elements that are arranged in the groups in said column, each first event signal and second event signal being generated in response to detecting an event by a respective event generation element; an interface configured to output an address and data of the group in which the event occurs, based on the generated first and second group event signals, wherein the interface comprises: a first arbiter configured to select one of at least one first group event signal, in response to the at least one first group event signal; and a second arbiter configured to select one of at least one second group event signal, in response to the at least one second group event signal corresponding to the selected first group event signal; a first arbiter configured to select one of at least one first group event signal, in response to the at least one first group event signal; and a second arbiter configured to select one of at least one second group event signal, in response to the at least one second group event signal corresponding to the selected first group event signal; wherein the first arbiter is configured to output a first address corresponding to the row for which the selected first group event signal was generated, wherein the second arbiter is configured to output a second address corresponding to the column for which the selected second group event signal was generated, and wherein the interface further comprises a data output unit configured to output data of the event generation elements arranged in the group that corresponds to the first address and the second address, and wherein the event is to occur when a change of light is sensed for a pixel corresponding to an event generation element of the group.