A method for arbitration during a self-organization process in an imaging system comprising: first and second input modules for distributing respective images; and a plurality of microtile units (1'A...1'J) each comprising a projection device; wherein said plurality of microtile units (1'A...1'J) and said first input module and said second input module are in communication with each other, such that each of the plurality of microtiles is enabled to receive at least one image from said first input module or said second input module and generate a respective portion of said at least one image and project said generated portion via its projection device; wherein said first and second input modules are enabled to send command signals to each of the plurality of microtile units and to each other, such that in said self-organization process: 1. each input module sends to each said microtile unit (1'A...1'J) a command signal causing the microtile unit to detect the presence of adjacent microtile units and communicate the detection result to the input module from which the command signal was received; and 2. each input module establishes a spatial relationship between said plurality of microtile units on the basis of the detection result; the method characterised by comprising the steps of: designating one of said first input module and said second input module as a system master, when said first input module and said second input module encounter one another during said self-organization process by: receiving, at at least one of the input modules in response to a request for identification from said at least one of the input modules: an indication from a microtile unit that the microtile unit is connected to the other input module; or an identifying code from the other input module; wherein said designation is made on the basis of at least one of: determining which of said first input module and said second input module has a newer firmware revision; and determining which of said first input module and said second input module has already organized a largest number of said microtile units; and wherein the input module designated as system master controls the self-organisation process thereafter. first and second input modules for distributing respective images; and a plurality of microtile units (1'A...1'J) each comprising a projection device; wherein said plurality of microtile units (1'A...1'J) and said first input module and said second input module are in communication with each other, such that each of the plurality of microtiles is enabled to receive at least one image from said first input module or said second input module and generate a respective portion of said at least one image and project said generated portion via its projection device; wherein said first and second input modules are enabled to send command signals to each of the plurality of microtile units and to each other, such that in said self-organization process: 1. each input module sends to each said microtile unit (1'A...1'J) a command signal causing the microtile unit to detect the presence of adjacent microtile units and communicate the detection result to the input module from which the command signal was received; and 2. each input module establishes a spatial relationship between said plurality of microtile units on the basis of the detection result; 1. each input module sends to each said microtile unit (1'A...1'J) a command signal causing the microtile unit to detect the presence of adjacent microtile units and communicate the detection result to the input module from which the command signal was received; and 2. each input module establishes a spatial relationship between said plurality of microtile units on the basis of the detection result; the method characterised by comprising the steps of: designating one of said first input module and said second input module as a system master, when said first input module and said second input module encounter one another during said self-organization process by: receiving, at at least one of the input modules in response to a request for identification from said at least one of the input modules: an indication from a microtile unit that the microtile unit is connected to the other input module; or an identifying code from the other input module; designating one of said first input module and said second input module as a system master, when said first input module and said second input module encounter one another during said self-organization process by: receiving, at at least one of the input modules in response to a request for identification from said at least one of the input modules: an indication from a microtile unit that the microtile unit is connected to the other input module; or an identifying code from the other input module; receiving, at at least one of the input modules in response to a request for identification from said at least one of the input modules: an indication from a microtile unit that the microtile unit is connected to the other input module; or an identifying code from the other input module; an indication from a microtile unit that the microtile unit is connected to the other input module; or an identifying code from the other input module; determining which of said first input module and said second input module has a newer firmware revision; and determining which of said first input module and said second input module has already organized a largest number of said microtile units; and wherein the input module designated as system master controls the self-organisation process thereafter.