Abstract:
A memory management system for generating 3-dimensional computer images is provided. The memory management system includes a device for subdividing an image into a plurality of rectangular areas, a memory for storing object data pertaining to objects in the image which fall in each rectangular area, a device for storing the object data in the memory, a device for deriving image data and shading data for each rectangular area from the object data, a device for supplying object data for each rectangular area from the respective portion of the memory and, if the rectangular area contains objects also falling in at least one other rectangular area, also from the global list, to the deriving device, and a device for storing the image data and shading data derived by the deriving device for display. The memory includes at least one portion allocated to each rectangular area and at least one portion allocated as a global list.
Abstract:
A memory management system for generating 3-dimensional computer images is provided. The memory management system includes a device for subdividing an image into a plurality of rectangular areas, a memory for storing object data pertaining to objects in the image which fall in each rectangular area, a device for storing the object data in the memory, a device for deriving image data and shading data for each rectangular area from the object data, a device for supplying object data for each rectangular area from the respective portion of the memory and, if the rectangular area contains objects also falling in at least one other rectangular area, also from the global list, to the deriving device, and a device for storing the image data and shading data derived by the deriving device for display. The memory includes at least one portion allocated to each rectangular area and at least one portion allocated as a global list.
Abstract:
An apparatus and a method for generating 3-dimensional computer graphic images. The image is first sub-divided into a plurality of rectangular areas. A display list memory is loaded with object data for each rectangular area. The image and shading data for each picture element of each rectangular area are derived from the object data in the image synthesis processor and a texturizing and shading processor. A depth range generator derives a depth range for each rectangular area from the object data as the imaging and shading data is derived. This is compared with the depth of each new object to be provided to the image synthesis processor and the object may be prevented from being provided to the image synthesis processor independence on the result of the comparison.
Abstract:
There is provided a method and apparatus for motion estimation in a sequence of video images. The method comprises a) subdividing each field or frame of a sequence of video images into a plurality of blocks, b) assigning to each block in each video field or frame a respective set of candidate motion vectors, c) determining for each block in a current video field or frame, which of its respective candidate motion vectors produces a best match to a block in a previous video field or frame, d) forming a motion vector field for the current video field or frame using the thus determined best match vectors for each block, and e) forming a further motion vector field by storing a candidate motion vector derived from the best match vector at a block location offset by a distance derived from the candidate motion vector. Finally, steps a) to e) are repeated for a video field or frame following the current video field or frame. The set of candidate motion vectors assigned at step b) to a block in the following video field or frame includes the candidates stored at that block location at step e) during the current video field or frame The method enables a block or tile based motion estimator to improve its accuracy by introducing true motion vector candidates derived from the physical behaviour of real world objects.
Abstract:
An apparatus and a method for generating 3-dimensional computer graphic images. The image is first sub-divided into a plurality of rectangular areas. A display list memory is loaded with object data for each rectangular area. The image and shading data for each picture element of each rectangular area are derived from the object data in the image synthesis processor and a texturizing and shading processor. A depth range generator derives a depth range for each rectangular area from the object data as the imaging and shading data is derived. This is compared with the depth of each new object to be provided to the image synthesis processor and the object may be prevented from being provided to the image synthesis processor independence on the result of the comparison.
Abstract:
A method and apparatus are provided for motion estimation in a sequence of images. One or more motion vectors representing movement of a camera or viewer position or direction are determined between each pair of fields or frames in the sequence of images. A set of candidate motion vectors is then determined for deriving positions of objects in a field or frame from the positions of objects in a previous field or frame. This set of candidate motion vectors is adjusted using the motion vectors representing movement of camera or viewer position and thus a set of motion vectors is derived for a sequence of images using the adjusted set of candidate motion vectors.
Abstract:
A 3-dimensional computer generated image is generated by subdividing the image into a plurality of rectangular areas. Object data for each rectangular area is loaded into a display list memory (4) until that memory is substantially full. Image data and shading data for each picture element of each rectangular area is derived by an image synthesis processor (6) from the object data. Image data is then stored in a local memory (16) and further object data loaded into the display list memory (4) and replaces the existing contents. Once this has happened, the stored image data and shading data is retrieved and additional image data and shading data derived for each picture element by the image synthesis processor (6) using the new object data and the previously derived image and shading data. When there is no further object data to load to the display list memory the shading data is provided for display for the rectangular areas by a frame buffer 11. The memory may be managed by allocating at least one block of storage from the display list memory to each rectangular area and then storing in that block of memory, data which pertains to surfaces which intersect that rectangular area. A determination is made as to when a predetermined number of blocks have been used for a rectangular area. When this number is reached, the system starts to derive shading data for the rectangular areas, thereby releasing blocks of storage to be allocated to further rectangular areas in the display list memory.
Abstract:
A method for enhancing an edge transition in a video signal comprising the steps of receiving a video signal including an edge transition, generating a correction signal for the edge transition, applying the correction signal to the video signal to produce a corrected signal and restricting the amplitude of the corrected signal to extend between extended maximum and minimum amplitude limits in dependence on the measured maximum and minimum amplitudes of a predefined pattern of pixels adjacent to the edge transition.
Abstract:
A method and apparatus are provided for motion estimation in a sequence of images. One or more motion vectors representing movement of a camera or viewer position or direction are determined between each pair of fields or frames in the sequence of images. A set of candidate motion vectors is then determined for deriving positions of objects in a field or frame from the positions of objects in a previous field or frame. This set of candidate motion vectors is adjusted using the motion vectors representing movement of the camera or viewer position and thus a set of motion vectors is derived for a sequence of images using the adjusted set of candidate motion vectors.
Abstract:
A method and apparatus are provided for motion compensated video interpolation. Each field or frame in a sequence of video images is subdivided into a plurality of blocks and a motion vector field is derived using block matching for a current video field using data matched to a previous video field or frame. A first time instance is determined at which an interpolated block is to be displayed and a second time instance is determined at which a corresponding interpolated block is to be created. Video data for each block is interpolated at its second time instance for each block and is then output for display at the first time instance.