Multicode multiplex spectral imaging

A method for measuring a set of input flux amplitudes comprising:

• providing at least one flux detector arranged to provide an output signal responsive to flux applied thereto;
• providing a hierarchal array of a plurality of logical encoder devices having a first level of first logical encoder devices and at least one second level of second logical encoder devices;
• wherein one of said second level is a final level;
• where each logical encoder device of the first level receives the set of input flux amplitudes on an input path and outputs linear combinations of said input flux amplitudes according to a first level sequence of encodings along at least one output path of the first level logical encoder devices;
• arranging the logical encoders such that the linear combinations of flux amplitudes on each output path of the first level defines the input flux amplitude of one logical encoder devices of said second level;
• where each logical encoder device of the second level receives the set of input flux amplitudes on the output path from one of the first level and outputs linear combinations of said input flux amplitudes according to a second level sequence of encodings along at least one output path of the second level logical encoder device;
• wherein each linear combination of flux amplitudes output along each output path does not include at least one input flux amplitude;
• and wherein said one or more output paths of each of the final level logical encoder devices is directed to a respective one of said at least one flux detector;
• wherein said at least one flux detector measures the total amplitude of the linear combinations of input flux amplitudes selected by the final level logical encoder device and all prior level logical encoder devices and provides said output signal in response thereto;
• and applying an algorithm to the output signal from said at least one flux detector to calculate the input flux amplitudes therefrom.