Canon Kabushiki Kaisha

Dominic Yip

James Philip Andrew

Ian Richard Gibson

Andrew Peter Bradley

Trevor Robert Elbourne

Kieran Gerard Larkin

Andrew James Dorrell

Mark Pulver

Kai Huang

Hiren Patel

Disclosed is a method and apparatus for clamping the output values of filtered image data comprising a mapping of discrete sample values are disclosed. For each discrete sample value of the mapping a maximum sample value and a minimum sample value of a plurality of input discrete samples values used to calculate the discrete sample value, is determined. The output value of the discrete sample value is clamped to the domain of the plurality of input discrete sample values utilising the maximum sample value and the minimum sample value, wherein the output value is dependent on a plurality of attributes of the plurality of input discrete sample values.

Color clamping

The preferred method wavelet filters a digital image. The digital image comprises a plurality of pixels arranged in a plurality of columns and rows. The method processes one or more bands of pixels of the image in turn, where each band comprises a plurality of rows. The method performs the following steps for each column in each one of the one or more bands of pixels. The method retrieves () a last pixel and last high pass coefficient previously stored in local storage. The method also inputs () a current group of adjacent pixels. The method then computes () the low and high pass wavelet coefficients utilizing the current group of adjacent pixels and the previous last pixel and last high pass coefficient. The method then outputs the low and high pass coefficients, and stores () a current last pixel and high pass coefficient in either the local storage or external memory.

Wavelet filtering

A method and apparatus () for estimating the blur parameters of blurred images (g, g) are disclosed. The apparatus () has one or more image sensors () for capturing the blurred images (g, g), a plurality of correlators () for performing autocorrelation of the blurred image (g) and cross-correlation between the two images (g, g) respectively, and an error function calculator () for evaluating an error function over all possible displacements using the results from the correlators (). The apparatus () further includes an extreme locater () for finding the displacement with the minimum value for the error function.

Method and apparatus for uniform lineal motion blur estimation using multiple exposures

A method of resolution conversion is disclosed. The method calculates a scaling factor for a first set of discrete data values compared to said second set of discrete data values. A plurality of filter function coefficients are calculated, based on the scaling factor, utilising at least one of a plurality of filter functions. The filter function coefficients are stored and later used to perform interpolation on the first set of discrete data values to generate the second set of discrete data values at a different resolution.

Continuous kernel image interpolation

The method encodes a digital image to provide a compressed representation of the image. The method initially performs a multi-level 2-D Discrete Wavelet Transform on the digital image, which is arranged in a hierarchical order of sub-bands. The method then tiles each sub-band to form a number of blocks of transform coefficients. The method then encodes each bitplane of each block from a maximum bitplane to a minimum bitplane in the following manner. The method divides a current bitplane into a number of first areas and/or a number of second areas, wherein each first area comprises a number of coefficients having corresponding most significant bits in the current bitplane or less and each second area comprises a number of coefficients having corresponding most significant bits in a bitplane greater than the current bitplane. The method then codes the significance of each first area in the current bitplane; and codes a corresponding bit of each coefficient in each second area of the current bitplane.

Encoding method and apparatus for representing a digital image

There is disclosed apparatus ( ) for accessing items of information. The apparatus ( ) comprises sixteen memory banks ( ) and an address generator ( ). Each of the sixteen memory banks ( ) stores items of information associated with and corresponding to respective symbols of a sub-set of the symbols. These sub-sets of symbols are mutually exclusive and together comprise a set of symbols. The items of information of the sixteen memory banks ( ) together constitute the whole of the items of information associated with and corresponding to the respective symbols of the set of symbols with no duplication of the items of information. The address generator ( ) simultaneously generates sixteen addresses for the respective sixteen memory banks ( ) in response to one input address, wherein the memory banks ( ) output sixteen items of information associated with and corresponding to the respective symbols within a 4&times;4 neighbourhood of the symbol corresponding to said input address.

Accessing sub-blocks of symbols from memory

A method of entropy coding symbols representative of a code block comprising transform coefficients of a digital image. The method comprises a significance propagation pass , a magnitude refinement pass , and a cleanup pass for entropy coding the symbols. The method generates ( ), prior to the significance propagation pass of the current bitplane, a first list of positions of those coefficients in the code block that have symbols to be entropy coded during the significance propagation pass of the current bitplane. The method also generates ( ), prior to the magnitude refinement pass of the current bitplane, a second list of positions of those said coefficients in the code block that have symbols to be entropy coded during the magnitude refinement pass of the current bitplane. The method further generates ( ), prior to the cleanup pass of the current bitplane, a third list of positions of those said coefficients in the code block that have symbols to be entropy coded during the cleanup pass of the current bitplane.

Generating lists of positions of coefficients in a code block to be entropy coded

The method decodes an compressed representation of a digital image. The compressed representation is in the form of a bitstream comprising in sequence encoded bitplanes each having first portions representative of the significances of first sub-regions in the current bitplane and second portions representative of respective bits of each coefficient in second sub-regions of the current bitplane. The method decodes each bitplane of a block of transform coefficients from a maximum bitplane to a minimum bitplane in the following manner. The method decodes the first portion as the respective significances of the first sub-regions in the current bitplane and decodes the second portion as the respective bits of each coefficient in the second sub-regions of said current bitplane.

Method and apparatus for decoding a coded representation of a digital image

An apparatus is disclosed for decoding a stream of previously encoded coefficients including input means for receiving the stream of encoded coefficients; bit plane level monitoring means connected to the input means and adapted to monitor a current bit plane level from the stream of coefficients; pixel generation means interconnected to the input means and the bit plane level monitoring means and adapted to utilize the current bit plane level for generating output coefficient values each having a predetermined size. The bit plane level monitoring means can include a finite state control machine interconnected to the input means and adapted for determining bit plane level changes in the coefficient input stream; a counter interconnected to the finite state control machine for monitoring a current bit plane level; a heap store interconnected to the counter and the finite state control machine and adapted store bit plane level values for utilization in recursion operations by the finite state control machine; and wherein the finite state machine acts to decrement the counter upon the receipt of a bit level change indicator in the coefficient input stream and further to control the reloading of the counter upon completion of the recursion operations.

Method and apparatus for decoding

The present invention relates to an image processor (,) comprising a control register block (,), a decoding block (,), a data object processor (,), and flow control logic. The control register block (,) stores all the relevant information about the image processing operation. The decoding block (,) decodes the information into configuration signals, which configure an input data object interface (,). The input data object interface (,) accepts and stores data objects from outside, and distributes these data objects to the data object processor (,). For some image processing operations, the input data object interface (,) may also generate addresses for data objects, so that the source of these data objects can provide the correct data objects. The data object processor (,) performs arithmetic operations on the data objects received. The flow control logic controls the flow of data objects within the data object processing logic (,). More particularly, the data object processor (,) can comprise a number of identical data object sub-processors, each of which processes part of an incoming data object.

General image processor

An apparatus for the encoding of a series of wavelet coefficients of a predetermined size into a compact representation of the coefficients. The apparatus comprises a tree builder for constructing a tree form representation of the coefficients with leaf nodes representing coefficient values and internal nodes representing the number of bits needed to encode leaf nodes and child nodes of a current internal node. The tree builder stores the tree form representation in a tree buffer of the apparatus, and the tree buffer stores the tree form representation. A tree coder of the apparatus is interconnected to the tree buffer and adapted to read a current tree form representation and to output the encoding from the tree form representation. The tree buffer can include a component for storing at least two tree form representations and the tree builder can be adapted to form a first of the representations while the tree coder can be adapted to read a second of the tree form representations previously created by the tree builder.

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Lindfield, Australia

Dominic Yip