Method for enhancing polarimeter systems that use micro-polarizers

A image processing apparatus, comprising;

• an image input device that inputs a sequence of angular-position-dithered frames, each frame consisting of under-sampled multi-polarization images;
• a shift estimator that estimates a shift for each angular-position-dithered frame for each of the multiple polarization images;
• an align and up-sample processor that aligns the current frame with reference frame coordinates defined by the first frame wherein,
• the align and up-sample processor further includes:
• a channel offset adder that adds a known polarization registration offset to the dithered shift estimates, Sx, Sy, and
• an image resampler at up-sampled, shifted positions that resamples the current frame, combines the resampled current frame with the registered and up-sampled images from other frames;
• and
• a polarization feature processor that combines the multiple polarization images to form a resultant image of polarization features.

A computer-readable storage medium having a computer program stored therein, the computer program when executed causes a computer to perform a steps of:

• inputting a sequence of angular-position-dithered frames of data, each frame consisting of under-sampled multi-polarization images;
• estimating pixel shifts for each of the angular-position-dithered frames relative to the position of the first frame of the sequence of frames;
• aligning and up-sampling the current frame for each polarization image to produce over-sampled data in a reference frame defined by the first frame of the sequence, wherein the aligning and up-sampling steps include:
• computing a registration shift ΔX, ΔY, for each polarization channel that is the sum of a fixed and known polarization-channel registration offset and the current frame's estimated pixel shifts due to dither;
• interpolating and up-sampling the current frame for each polarization channel using registration shift ΔX, ΔY to generate pixel data that is over-sampled and registered to the reference frame;
• integrating the registered, over-sampled images for each polarization channel for the sequence of frames;
• and
• outputting features formed by combining the polarization channels, pixel-by-pixel, to form an image of polarization features.