Abstract: The present invention relates to processing of coded aperture images. Multiple frames of data acquired by the coded aperture imaging system, each with a different coded aperture array, are processed to form an image. The processing incorporates the constraints that the image solution must be positive and that the solution should be zero outside an expected image region. In one embodiment image enhancement may involve dividing the processed image into image regions having a spatially invariant point spread function and solving an inverse problem for each image region to reduce image blurring.

Abstract: Optically diverse coded aperture imaging (CAI) includes imaging a scene which is multi-spectrally diverse or polarimetrically diverse. A CAI system allows light rays from a scene to pass to a detector array through a coded aperture mask within an optical stop. The mask has multiple apertures, and produces overlapping coded images of the scene on the detector array. Detector array pixels receive and sum intensity contributions from each coded image. The detector array provides output data for processing to reconstruct an image. The mask provides for multi-spectral information to become encoded in the data. A linear integral equation incorporating explicit wavelength dependence relates the imaged scene to the data. This equation is solved by Landweber iteration to derive a multi-spectral image. An image with multiple polarisation states (polarimetric diversity) may be derived similarly with a linear integral equation incorporating explicit polarisation dependence.

Abstract: A method of reconstructing an image of a scene (4) from data output by a detector (8) in a coded aperture imaging system (2) comprises taking multiple frames of data using a different coded aperture array 6 for each frame. For each frame of data a decoding pattern is employed which is point source diffraction pattern corresponding to the coded aperture array used to acquire that frame. The decoding patterns are combined in a Gram matrix. A two-dimensional to one-dimensional mapping is applied to the frames of data. A solution to the data is constructed which is related to the scene (4) by an integral operator. The integral operator has an averaging kernel with a main lobe width which is smaller than the detector pixel size. Processing of the data yields an image which has sub-pixel resolution, i.e. resolution greater than the native resolution of the detector (8).

Abstract: The present invention relates to processing of coded aperture images. Multiple frames of data acquired by the coded aperture imaging system, each with a different coded aperture array, are processed to form an image. The processing incorporates the constraints that the image solution must be positive and that the solution should be zero outside an expected image region. In one embodiment image enhancement may involve dividing the processed image into image regions having a spatially invariant point spread function and solving an inverse problem for each image region to reduce image blurring.