A deferred shading graphics pipeline processor and method are provided encompassing numerous substructures. Embodiments of the processor and method may include one or more of deferred shading, a tiled frame buffer, and multiple?stage hidden surface removal processing. In the deferred shading graphics pipeline, hidden surface removal is completed before pixel coloring is done. The pipeline processor comprises a command fetch and decode unit, a geometry unit, a mode extraction unit, a sort unit, a setup unit, a cull unit, a mode injection unit, a fragment unit, a texture unit, a Phong lighting unit, a pixel unit, and a backend unit.

Deferred shading graphics pipeline processor having advanced features

The present invention is a nonlinear joint transform image correlator which employs a spatial modulator operating in a binary mode at the Fourier plane. The reference and input images are illuminated by a coherent light at the object plane of a Fourier transform lens system. A image detection device, such as a charge coupled device, is disposed at the Fourier plane of this Fourier transform lens system. A thresholding network detects the median intensity level of the imaging cells of the charge coupled device at the Fourier plane and binarizes the Fourier transform interference intensity. The correlation output is formed by an inverse Fourier transform of this binarized Fourier transform interference intensity. In the preferred embodiment this is achieved via a second Fourier transform lens system. This binary data is then applied to spatial light modulator device operating in a binary mode located at the object plane of a second Fourier transform lens system. This binary mode spatial light modulator device is illuminated by coherent light producing the correlation output at the Fourier plane of the second Fourier transform lens system. The inverse Fourier transform may also be formed via a computer. In an alternative embodiment, the Fourier transform interference intensity is thresholded into one of three ranges. An inverse Fourier transform of this trinary Fourier transform interference intensity produces the correlation output.

Joint transform image correlation using a nonlinear spatial light modulator at the fourier plane

Flash correlation instantaneously compares (52) two or more patterns (20, 50) to determine whether they are the same or essentially the same regardless of the complexity of the images, and in spite of the addition of noise, local changes, and variations in resolution and focus. Flash correlation artifacts (58) also provide cues to quantitative assessment of relative movement, stretching, blurring, and warping of one image with respect to the other. Presence of a flash correlation artifact between two stacks of patterns (58) is sufficient to identify the stacks as containing at least one pair of massively correlated patterns (62). Precise control of registration, image size and orientation is not required. An image may be combined with other images, either by overlays or concatenation, and still be identified. A flash correlation engine may utilize optical, analog or digital processing to provide rapid sorting, classification, and identification functions with minimal computational complexity.

Method and apparatus for flash correlation.

An all-optical nonlinear joint transform correlator has been implemented for the first time without using a spatial light modulator and digital processing in the Fourier plane. The correlator utilizes energy transfer from two-beam coupling in the Fourier plane. A compressional nonlinearity in the hard-clipped regime is implemented by pumping a weak plane wave with the intense joint spectrum of the reference and signal images. Operation of this device rivals or exceeds that of the phase-only filter for detecting objects in cluttered noise. Experimental results are compared with both plane wave and beam propagation simulations.

Photorefractive two-beam coupling nonlinear joint transform correlator

Method and apparatus for computing cross-correlations with application to image processing and video motion estimation, particularly in video compression applications, are described. Two-dimensional Fourier transform convolution techniques form a basis for novel techniques for performing two simultaneous two-dimensional cross correlations. The size of the input data blocks for the transformations are arbitrary. Apparatus for efficiently performing real-time cross correlations, including cross-correlations using Short Length Transforms (SLTs), using cascaded stages, multi-port memories, and multiple arithmetic units are also described. In video motion vector estimator application, data blocks within a current video frame are selected and converted to form a two-dimensional matrix of complex data. The complex matrix is transformed to the frequency domain to form the frequency domain representations of the selected data blocks. A set of search blocks within the previous video frame having a one-to-one correspondence with the selected data blocks, is then selected, converted into a complex data matrix, and transformed to the frequency domain to form the frequency domain representations of the selected search blocks. Once in the frequency domain, the sets of data corresponding to the data blocks and the search blocks are multiplied together and the product is inverse transformed to return to the spatial domain. The data then passes through an adjustment process to form the cross-correlations between the pairs of data blocks and search blocks.

System and method for cross correlation with application to video motion vector estimator

A real-time programmable joint transform optical correlator incorporating a magneto-optic spatial light modulator and a liquid crystal light valve therein. Object functions to be correlated are input into the magneto-optic spatial light modulator by a programmable microcomputer as input signals. Real time correlation takes place at the liquid crystal light valve with a coherent read out beam. Cross correlation between the input functions (signals) are obtained through the inverse Fourier transform of the read out coherent illumination and are subsequently output from the correlator.

Francis T. S. Yu

Papers

Real-time programmable optical correlator