1. Field of the Invention
This invention relates to the processing of image data.
2. Description of the Prior Art
The processing of image data is a well established technical field. Image data can be captured in many different forms. For example, image data may be captured by still/moving image photographic cameras or still/moving image electronic cameras. Once the image data has been captured, it is typically transformed into a stream of data according to a known image data format, such as PAL, NTSC, SECAM or SMPTE 240M.
There exist many different pieces of equipment for performing manipulations upon image data in the aforementioned formats. The manipulations can take many different forms. For example, the manipulation may be recording onto magnetic tape, processing through a digital video effects system, motion compensated standards conversion or spatial filtering.
As the technical field of the capture, manipulation and reproduction of image data has advanced, this has made possible the use of increasingly high resolution systems. At the present time this technical field is at the start of a transitional period between the use of formats such as PAL, NTSC and SECAM and the use of a new generation of high definition of video formats.
A major obstacle that stands in the way of such evolution is the vast amount of investment and development effort that must be expended to produce apparatus for manipulating data in these new higher resolution formats. As spatial and temporal resolution increases the rate at which image data must be handled increases to an extent that the sophistication of the equipment used must be significantly increased so as to cope. This is a hugely expensive undertaking.
One possible way in which the use of higher resolution formats may be facilitated is to split the source stream of data into a number of separate split streams of data each having only part of the information content of the source stream of data. The lowering of the information content of the split streams of data may be sufficient to allow existing or slightly modified equipment, originally designed for use with lower resolution formats, to be employed. This technique can be thought of as providing a hierarchial philosophy in which systems of increased resolution can be built from combining pieces of equipment that were originally produced for lower resolution operation.
Whilst the above is a superficially attractive approach, it brings with it its own set of problems which must be solved if its use is to be practical. In particular, the splitting, manipulation and combining of the data can introduce distortions into the image data that did not occur, or were not relevant, when the lower resolution equipment was being used upon data in the format for which it was originally intended.
It is an object of the invention to provide apparatus for processing image data adopting the above described hierarchial philosophy that has a reduced level of distortions due to the splitting, manipulation and combining of the data.