Image indexing systems
OwnerIan Fletcherinventor
Life of this patent
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Abstract
An image indexing system comprising a video frame store, an averager which provides a first signal indicative of the average brightness level of each frame stored, an image splitter and averager which divides each frame into contiguous blocks of pixels, and provides for each block, a second signal indicative of its average brightness level, a comparator which compares each of the second signals with the first signal so as to produce in respect of each block a binary signal indicative of whether or not its brightness level, as indicated by the first signal, is greater or less than the average brightness level for the frame as indicated by the first signal, thereby to produce for each frame, an index signal comprising one binary bit for each block which serves to identify each frame for indexing purposes.
Claims10
An image indexing system comprising a video frame store, an averager which provides a first signal indicative of the average brightness level of each frame stored, an image splitter and averager which divides each frame into contiguous blocks of pixels, and provides for each block, a second signal indicative of its average brightness level, a comparator which compares each of the second signals with the first signal so as to produce in respect of each block a binary signal indicative of whether or not its brightness level, as indicated by the first signal, is greater or less than the average brightness level for the frame as indicated by the first signal, thereby to produce for each frame, a index signal comprising one binary bit for each block which serves to identify each frame for indexing purposes.
An image indexing system as claimed in any preceding claim, wherein the imager splitter operates to divide each frame into rows and columns of contiguous rectangular pixel blocks.
An image indexing system as claimed in any preceding claim which forms a part of image identification apparatus and which additionally comprises a database in which the binary index for each of a plurality of images is stored and a further comparator wherein an index of an image to be identified as established by the image indexing system, is compared with indices stored in the database, thereby to provide an output signal when the index of the image to be identified corresponds to the index of a stored image, the output signal including data which identifies the stored image in respect of which correspondence obtains.
An image indexing system as claimed 7, wherein the threshold for selection is arranged to be variable so that it can be set to correspond to a predetermined percentage match.
An image indexing system as hereinbefore described with reference to the accompanying drawings.
Image identifying apparatus substantially as hereinbefore described with reference to the accompanying drawings.
Dependencies are inferred from the claim text.