69 results about "Computational complexity theory" patented technology

The use of parametric models to capture and represent local signal geometry allows a new geometric intra prediction scheme to better encode video images. The encoding scheme gives the video encoder the flexibility and scalability to match the video frame content with the desired computational complexity. It also allows the encoder to encode the images more efficiently using intra prediction because it reduces the artificial edges that occur during standard intra encoding.

A method and a system for reducing computational complexity in a maximum-likelihood MIMO decoder, while maintaining its high performance. A factorization operation is applied on the channel Matrix H. The decomposition creates two matrixes: an upper triangular with only real-numbers on the diagonal and a unitary matrix. The decomposition simplifies the representation of the distance calculation needed for constellation points search. An exhaustive search for all the points in the constellation for two spatial streams t(1), t(2) is performed, searching all possible transmit points of (t2), wherein each point generates a SISO slicing problem in terms of transmit points of (t1); Then, decomposing x,y components of t(1), thus turning a two-dimensional problem into two one-dimensional problems. Finally searching the remaining points of t(1) and using Gray coding in the constellation points arrangement and the symmetry deriving from it to further reduce the number of constellation points that have to be searched.

There are disclosed three fast rate control methods that can efficiently reduce or remove the computation and memory usage redundancy over conventional PCRD methods. The first method, called successive bit-plane rate allocation (SBRA), assigns the maximum allowable bit-rate for each bit-plane of each code-block by using the currently available rate-distortion information only. The second method is called priority scanning rate allocation (PSRA). This first predicts the order of magnitude of each truncation point's rate-distortion slope and then encodes the truncation points based on the order (priority) information. The third method uses PSRA to obtain a significantly smaller amount of data than PCRD for optimal truncation and is called priority scanning with optimal truncation (PSOT). SBRA provides the highest computational complexity and memory usage reduction, and the lowest coding / transmission delay. The computational complexity reduction can be up to about 90% of the entropy coding process. However this method gives the lowest PSNR performance of the three. PSRA provides higher PSNR performance than SBRA with the penalty of lower memory usage reduction and higher delay. PSOT provides the best (optimal) quality while it is the least efficient method in term of computational complexity, memory usage and the coding / transmission delay. The three methods provide different degree of computation complexity and memory reduction, coding / transmission delay and PSNR performance. The most suitable rate control method can be chosen based on application requirements.

A decision tree for classifying computer files is constructed. Computational complexities of a set of candidate attributes are determined. A set of attribute vectors are created for a set of training files with known classification. A node is created to represent the set. A weighted impurity reduction score is calculated for each candidate attribute based on the computational complexity of the attribute. If a stopping criterion is satisfied then the node is set as a leaf node. Otherwise the node is set as a branch node and the attribute with the highest weighted impurity reduction score is selected as the splitting attribute for the branch node. The set of attribute vectors are split into subsets based on their attribute values of the splitting attribute. The above process is repeated for each subset. The tree is then pruned based on the computational complexities of the splitting attributes.

In an embodiment, computational complexity of estimating the actual illuminant of a scene is reduced by examining only a subset of the pixel values generated for a received image frame. In another embodiment, number of rotations of color values is minimized by selecting an area which contains the color cue values of a color in an original / unrotated coordinate space and has boundaries which parallel the axis of the original coordinate space, and rotating a color value only if the color value is within the selected area. In another embodiment, such an area is used in conjunction with a histogram-based approach to determine the actual illuminant.