Nvidia Corporation

Ampex Corporation

Accom

Sohei Takemoto

Brian Keith Cabral

Hu He

Elena Ing

Kenneth A Woodhouse

Shang-Hung Lin

John D Stern

Luigi C Gallo

Leonard A Pasdera

Elena Lamburn

A system and method for correcting image data. Embodiments of the present invention provide calibration and image correction to overcome various lens effects including lens shading and lens imperfections. In one embodiment, the correction of image data is performed via utilization of a spline surface (e.g., Bezier surface). The use of spline surfaces facilitates efficient hardware implementation. The image correction may be performed on a per channel and illumination type basis. In another embodiment, the present invention provides a method for determine a spline surface to be used for calibrating an image signal processor to be used in correcting image data.

Method of calibrating an image signal processor to overcome lens effects

Techniques for per-channel image intensity correction includes linear interpolation of each channel of spectral data to generate corrected spectral data.

Per-channel image intensity correction

System and method for lens shading image correction

A system and method for correcting image data. Embodiments of the present invention provide image correction to overcome various lens effects, optical crosstalk, and electrical crosstalk. In one embodiment, the method includes accessing, within an electronic system, a plurality of control points for a patch of a spline surface and calculating a plurality of intermediate control points corresponding to a row of pixels of the patch. The method further includes receiving a pixel of an image and correcting the pixel based on the plurality of intermediate control points in streaming scanline column-wise or row-wise order.

System and method for performing image correction

An image processing apparatus for processing pixels is disclosed. The image processing apparatus comprises one or more functional blocks adapted to perform a corresponding functional task on the pixels. Further, the image processing apparatus includes one or more line-delay elements for delaying a horizontal scan line of the pixels. A desired processing task, which includes at least one functional task, is performed by configuring each functional block based on an actual number of the line-delay elements used for performing the desired processing task. Each functional block used for performing the desired processing task receives a group of pixels for processing from one or more horizontal scan lines such that the group overlaps another group of pixels for processing from one or more horizontal scan lines by another functional block.

Configurable and compact pixel processing apparatus

According to a presently preferred embodiment of the invention, image enhancement apparatus for digital video images comprises a two-stage filter comprising a median filter and a recursive filter. The median filter operates in one, two, and three dimensions wherein the cluster of pixels framing the center pixel are ranked, and the median value of the pixel cluster is chosen as the correct pixel value. The pixel cluster configuration is selectable, as are the planes where the pixels are located. Multiple weights may be given to the appropriate median filter inputs. A motion detector is used to prevent replacement of each pixel by its pixel cluster median value when there is excessive motion. Finally an adjustable pixel-replacement threshold is defined. Each pixel must deviate from its median value before it is replaced by that value. In the presence of rapid motion in the picture, the operation of the median filter is reduced or halted by a properly derived motion signal according to the present invention, thus preventing motion artifacts from occurring.

Three-dimensional median and recursive filtering apparatus and method

A digital image compositing system (20) has background, foreground, key and mask busses (22), (24), (26), and (28). An analog key input (30) is connected to the key and mask busses (26) and (28) through an analog/digital (A/D) converter (32) by crosspoint switches (34). Four digital D1 video signal inputs (36) are connected to the busses (22-24) through additional crosspoint switches (34). The key and mask busses (26) and (28) are respectively connected to frame stores (38) and (40). A key processing toolkit subsystem (42) is connected to the output of the frame stores (38) and (40). A compositor subsystem (44) is connected to the background and foreground busses (22) and (24) and to the output of the key processing toolkit subsystem (42). A D1 program output (46) is connected to the output of the compositor subsystem (44) on program bus ( 48). A D1 key output (50) is connected to the output of key processing toolkit subsystem (42) on processed key bus (52). A D1 auxiliary output (54) is connected to program bus (48), background bus (22), foreground bus (24), processed key bus (52) and mask bus (28) by crosspoint switches (56). An analog output (58) is also connected to the busses (48), (22), (24), (52) and (28) by additional crosspoint switches (56) through D/A converter (60). A microprocessor (62) is connected to provide control signals for all of the functional elements of the system (20). A control keyboard and display (64) is connected to the microprocessor at (66). The microprocessor (62) is also connected to a video editor at (68).

Digital image compositing system and method

Apparatus and methods for encoding information of one class into the parity for main data of another class. One such method and apparatus fundamentally takes one member A.sub.x of a limited first class of data called attribute data and concatenates it with main data. Parity is then calculated on the concatenate word. After the main data and parity is transmitted or recorded, the selected member of the first class of data may be recovered by comparing the received parity to the parity P' generated on the receiver side using the main data and each member of the first class of data to generate a plurality of syndromes. The first all zero syndrome identifies the member of the first class which was encoded into the parity of the main data. Another method and apparatus are similar except that the transmitter side calculates parity P.sub.ax for the selected member of the first class and then encodes that parity into the parity calculated for the main data. On the receiver side, parity bits are calculated for each member of the first class and then combined with parity P.sub.d ' calculated on the main data to generate parity P'. This parity P' is then compared to the received parity P', and the first match indicates which member of the first class was encoded on the transmitter side.

Growing community of inventors

Fremont, CA, United States of America

Sohei Takemoto