Canon Kabushiki Kaisha

Peter Alleine Fletcher

Kieran Gerard Larkin

Stephen James Hardy

Matthew Raphael Arnison

Allen Peter Courtney

David Peter Morgan-Mar

Ben Yip

Takeshi Yazawa

Timothy Merrick Long

James Austin Besley

Ian Richard Gibson

Tuan Quang Pham

Eric Wai-Shing Chong

Dmitri Katchalov

Ruimin Pan

Andrew Docherty

Yoichi Kazama

Scott Alexander Rudkin

Steven David Webster

Richard James Zillman

Tatiana Dudina

Steven Parker

Timothy Stephen Mason

A system and method determining a camera pose. The method comprises receiving a first image and a second image, the first and second images being associated with a camera pose and a height map for pixels in each corresponding image, and determining a mapping between the first image and the second image using the corresponding height maps, the camera pose and a mapping of the second image to an orthographic view. The method further comprises determining alignment data between the first image transformed using the determined mapping and the second image and determining a refined camera pose based on the determined alignment data and alignment data associated with at least one other camera pose.

System and method for determining a camera pose

A displacement field relating positions of pixels between at least two images having an initial displacement field is adjusted. Each pixel of the first image and the second image is associated with a label. A first pixel in the first image maps to a second pixel in the second image based on a vector of the initial displacement field. A set of third pixels includes the second pixel and a plurality of adjacent pixels to the second pixel, the third pixels being associated with labels and a candidate shift vector with respect to the second pixel. A covariance score is determined for each of the third pixels, the covariance score defining a statistical dependence between the first label of the first pixel and each of the third labels. An adjustment shift vector is then determined based on the covariance scores and the candidate shift vectors of the third pixels.

Image registration method

A method for processing microscopy images captures, for each of a first microscopy slide and a second microscopy slide, a plurality of partial spectrum images under multiple optical configurations where each image captures a different portion of the spectrum of the slide. First and second partial spectrum images associated with different optical configuration are selected and used to reconstruct respectively a combined spectrum image of part of the first microscopy slide and a combined spectrum image of at least part of the second microscopy slide, thereby forming a first pair of partial spectrum images. The method determines a distortion map by aligning images derived from the first pair of the partial spectrum images.

Physical registration of images acquired by Fourier Ptychography

A method for registering images aligns a fixed image with a corresponding moving image. A target image and a reference image are selected. The reference and target images are relatively low-res representations of the fixed and moving images respectively. A current image distortion map is determined that defines distortions between the target and reference images. A residual image is determined by comparing the reference image and a warped target image derived from the target image based on the current image distortion map. A residual image distortion map is determined based on transform coefficients of cosine functions fitted to the residual image. The coefficients are determined by applying a DCT to a signal formed by the residual image and image gradients of the warped target or reference image. The current image distortion map is combined with the residual image distortion map to align the fixed image and the moving image.

Systems and methods for registration of images

Disclosed is a computer implemented method for identifying a component tile within a target image. The method receives a plurality of distinct component tiles and overlays the plurality of component tiles to form an overlaid image. The overlaying is based on an embedded parameter value for each component tile. The method compares the target image with the overlayed image to determine a matching parameter value, and identifies a component tile within the target image by determining that the embedded parameter value of the component tile is the closest of the embedded parameter values to the matching parameter value.

Correlation using overlayed patches

A method for selecting a representative image of an eye from a plurality of captured images, comprises associating neighboring images from the plurality of images with each other to determine a spatial relationship (shift) of the images and an initial quality value for each image. The method determines an accumulated quality value for at least one portion of each image using the initial quality values corresponding to those other images of the plurality of images that are spatially related with the portion. The spatial relationship between a portion of an image and the other images is identified based of the determined spatial arrangement of the images. The method selects a representative image from the plurality of images using, for each image, at least the initial quality value for the image and the accumulated quality value of at least one portion of the image.

Ophthalmic reference image selection

Disclosed is method of measuring the displacement between a reference region of a reference image and a sample region of a sample image. The method spatially varies the reference region using a one-dimensional filter having complex kernel values, wherein a length (radius) and direction (angle or tangent segment) of the filter is a function of position in the reference region. The method then measures a displacement between the reference region and the sample region by comparing the spatially varied reference region and the sample region.

Estimation of shift and small image distortion

A method for determining a phase for a captured image, the method comprising forming a demodulated image defining wrapped phase values and modulation values, each being associated with at least one region in the captured image; identifying a position of an edge in the captured image dependent upon the modulation values; determining a position of substantial change in the wrapped phase values in the captured image dependent upon the identified position of the edge, and determining at least one unwrapped phase value based on the position of the edge and the position of the substantial change in the wrapped phase values by shifting a position of the substantial change in the wrapped phase values to the identified position of the edge, so that said unwrapped phase value is adjusted by at least one cycle.

Modulation guided phase unwrapping

Methods for determining a depth measurement of a scene which involve capturing at least two images of the scene with different camera parameters, and selecting corresponding image patches in each scene. A first approach calculates a plurality of complex responses for each image patch using a plurality of different quadrature filters, each complex response having a magnitude and a phase, assigns, for each quadrature filter, a weighting to the complex responses in the corresponding image patches, the weighting being determined by a relationship of the phases of the complex responses, and determines the depth measurement of the scene from a combination of the weighted complex responses.

Determining a depth map from images of a scene

A method determines at least one image value of a corresponding desired output position of an output image from an input image. An orientation of an edge passing through the output position is determined in a localised region of the input image. A frequency spectrum for the region of the input image is extended. A main frequency band of the edge is aligned in the extended frequency spectrum parallel to a first sampling axis of a grid based on the orientation of the edge. The grid is selected from a set of the input and output grids. The aligned main frequency band is filtered along a second sampling axis of the grid, orthogonal to the first sampling axis, the filter removing frequencies associated with replica bands and maintaining the main frequency band. The image value is determined from the filtered edge at the desired output position.

Image resampling by frequency unwrapping

A method () is described of determining characteristic of an ink jet printer (). A chart containing multiple regions or patches is printed () on a print medium () using the ink jet print (). The chart includes at least a first region printed using a first set of nozzles, and at least a second region printed using a second set of nozzles. The first and second sets of nozzles are a predetermined distance apart in the printer head of the printer (). The printing of the first and second regions is also separated by a print medium advance operation equal to the predetermined distance. This causes the first and second regions to be aligned in the direction of the print medium advance operation. The chart is then imaged using scanner () chart to form a chart image. The positions of the regions appearing in the chart image are next determined (). The spatial alignment characteristic of the printer is calculated from the distance, in the medium advance direction, between said first and second regions.

Method of measuring printer characteristics

Methods, apparatuses, systems and computer program products for measuring spatial characteristics of an inkjet printer are disclosed. Group of marks of a first predetermined pattern are printed on a print medium using a first group of nozzles. Groups of marks of a second predetermined pattern are printed using a second group of nozzles. A region of overlap of the printed groups of marks is formed. At least a portion of the print medium having printed groups of marks is imaged. From the region of overlap, first and second groups of marks from the first and second printed patterns are selected. For each group of marks, a position representative of that group is determined. An offset for measuring spatial characteristics of the printer between the first and second printed patterns is determined dependent upon the representative position of each of the first and second groups of marks.

Method of measuring printer spatial characteristics

A method determines displacements between pixels in a captured image of a reference pattern and corresponding pixels in the reference pattern including the steps of capturing the image of the reference pattern having a source pattern modulated by a plurality of carrier frequencies in a corresponding plurality of directions in the source pattern, demodulating at least three of the carrier frequencies in the captured image to form an amplitude image and a wrapped phase image for each of the carrier frequencies, and combining the wrapped phase images weighted by the amplitude images to determine the displacements between pixels in the captured image and corresponding pixels in the reference pattern.

Phase estimation distortion analysis

A method () of measuring performance parameters of an imaging device () is disclosed. The method () maintains a test pattern image (), the test pattern image () comprising alignment features and image analysis features. A test chart () containing a representation of the test pattern image is next imaged using the imaging device () to form a second image (). The test pattern image () and the second image () are then registered using region based matching () operating on the alignment features. Finally, the performance parameters are measured by analysing () the image analysis features.

Imaging system performance measurement

A system () and a method () are described for determining a two-dimensional position of a location in an image. The method () starts by imaging () a two-dimensional pattern (). The two-dimensional pattern comprises a plurality of at least partially overlapping two-dimensional sub-patterns (). The sub-patterns () repeat with different spatial periods to form the two-dimensional pattern, and the spatial period of the sub-patterns are anharmonic. A two-dimensional offset for each of the sub-patterns is then determined () at the location in the image formed by the imaging. The two-dimensional position is determined from said two-dimensional offsets.

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Rozelle, Australia

Peter Alleine Fletcher