Conventional camera designs (e.g. CCD or CMOS) commonly feature a single image sensor that uses a Bayer color filter array (CFA) to arrange red, green, and blue (RGB) color filters on a square grid of photosensors. However, the Bayer CFA acquires a limited amount of spectral information and is also susceptible to color aliasing and artifacts. This technology solves these issues by optimizing a generalized assorted pixel (GAP) arrangement to capture multispectral and high dynamic range (HDR) images simultaneously using a complex assortment of pixels. A color pixel detector architecture and an anti-aliasing algorithm are implemented as a new CFA that includes a series of primary filters and secondary filters, each with a particular spectral response. The information obtained from the filters is used to balance spectral resolution, dynamic range, and spatial resolution for generating a wide range of image types.
By implementing a complex array of primary and secondary color and photometric filters, the GAP array facilitates multispectral color acquisition beyond that achievable by the RGB Bayer array, as well as a superior dynamic range, all without the loss of spatial resolution from an increased grid size. Furthermore, it includes an anti-aliasing algorithm that allows for images collected on the larger grid to retain maximal spatial resolution with minimal distortion or artifact generation. Finally, the GAP array enables users to control the trade-off between spatial resolution, dynamic range, and spectral detail to generate a variety of images from a single collection event. The potential applications span numerous disciplines and offer improvements to any device utilizing high quality imaging data from a charge coupled device or complementary metal-oxide semiconductor.
The GAP camera has been validated using extensive simulations based on multispectral images of real world scenes. The results have been released in a large database for use by the research community.
Patent Pending (WO/2009/120928)
Tech Ventures Reference: IR M08-077