Patent ID: 7312829

Claim:
A method of determining a device spectral response for an image recording device, the method comprising: obtaining a filtered light response from a number of filters of a filter set, wherein each filter has a pass band with at least one boundary defined by a transition region, wherein in the wavelength region of interest, adjacent transition regions of the same sense are substantially non-overlapping in wavelength with respect to each of the other filters; storing the obtained filtered light response for each filter as response data; and determining the device spectral response using the stored response data and separately determined data describing the spectral response of the number of filters; wherein the step of determining the device spectral response comprises describing the spectral response of the number of filters of the filter set as an N by M matrix with N being the number of filters, such that for each filter, the spectral response is described as a series of M sampled values across the spectrum and wherein the matrix is formed from the said values for each filter of the number of filters, and multiplying the values representing the obtained filtered light response by the inverse matrix of the spectral response of the said filters, said inverse matrix being determined using singular value decomposition.