Abstract: There are provided: a pattern detection process section for extracting a partial image made of pixels including a target pixel from input image data; a rotated image generating section for generating a self-rotated image by rotating the partial image; and a matching test determination section for determining whether an image pattern included in the partial image matches an image pattern included in the self-rotated image. When it is determined that matching exists, a target pixel in the partial image or a block made of pixels including the target pixel is regarded as a feature point. Consequently, even when image data has been read while skewed with respect to a predetermined positioning angle of a reading position of an image reading apparatus or image data has been subjected to enlarging, reducing etc., a feature point properly specifying the image data can be extracted regardless of skew, enlarging, reducing etc.

Abstract: There are provided: a pattern detection process section for extracting a partial image made of pixels including a target pixel from input image data; a displaced image generation section for generating a self-displaced image by displacing at least a part of the partial image through a predetermined method; and a matching test determination section for determining whether an image pattern included in the partial image matches an image pattern included in the self-displaced image or not. When the matching test determination section determines that the matching exists, a target pixel in the partial image or a block made of pixels including the target pixel is regarded as a feature point. Consequently, even when image data is subjected to a process such as enlarging and reducing, it is possible to extract a feature point that properly specifies the image data regardless of the enlarging/reducing process.

Abstract: The invention relates to the authentication of users for a multi-function peripheral (MFP) device using handwritten signatures. Systems and methods are disclosed which relate to a MFP that conditions access to MFP operations based on an authenticating process that compares a prospective user's signature to previously saved signatures. The signatures are communicated to the MFP using the MFP's native scanning function.

Abstract: A terminal 102 creates setting data 400 and inputs setting data 400 into an image output apparatus 101. The image output apparatus 101 sets the initial settings, operation settings, equipment settings, etc. based on the setting data, holds the setting data, and performs various processes based on the set settings and the held setting data. In addition, the image output apparatus 101 performs a media identification process, a media reader switching process, and the like using a media detection means 117, a media reader switching means 118, and the like, and allows only the use of the insertion opening of a predetermined media reader.

Abstract: A method of detecting and compensating fail pixels in a holographic storage system. The method includes steps of: providing a plurality of image frames to show on a data plane for all pixels on the data plane being capable of outputting a light state or a dark state; sequentially recording the image frames into a storage medium; detecting the image frames by using a detecting apparatus for all pixels on the detecting apparatus being capable of outputting sensing signals corresponding to the light state and the dark state; defining a sensing difference value, which is a difference of the sensing signal outputting the light state and the dark state generated by one pixel; comparing the sensing difference value with a threshold value; and defining the corresponding pixel is a fail pixel if the sensing difference value is smaller than the threshold value.

Abstract: A method of re-locating an object in a sample is provided for a previously-scanned slide having determined objects each with corresponding stored coordinates and a stored image, the objects being mapped relative to each other. The slide is positioned on a microscope stage, stored images of the objects are visually displayed, and a target object is selected. The slide is moved to an estimated coordinate position, corresponding to the coordinates of the target object, and a field-of-view image of the sample is captured for comparison to the stored image of the target. If the target is in the image, an offset between actual coordinates of the located target and the stored coordinates of the corresponding object is determined. The slide is then moved, via the stage, from the estimated coordinate position, according to the offset, to center the target in the image. Associated systems and methods are also provided.

Abstract: An image capture apparatus includes a first imaging device operable to capture an image feedback image. A generator generates a feedback image from a captured image for output to a display. A facial recognition unit operates to determine the position of a face within the feedback image. An image corruptor operates to corrupt the feedback image with respect to the position of a face within the feedback image as determined by the facial recognition unit. An image capture initiator operates to initiate the capture of an output image subsequent to corruption of the feedback image.

Abstract: A disclosed image processing apparatus includes process components configured to input, process, or output image data; and a registration unit configured to obtain a list of the process components available in the image processing apparatus, to display on a display unit a screen for selecting one or more of the process components from the list and thereby defining a combination of the process components which combination implements an application program for performing an image processing task, and to register the combination with an identifier in the image processing apparatus.

Abstract: A positioning measurement method is provided. The method includes the step of: capturing images of a standard object and to-be-measured objects; selecting one or more standard points from the image of the standard object; selecting a general location area and a standard area by taking each standard point as a reference point; generating a script for recording positions of each general location area and capturing a standard image in each standard area; storing the script into the data storage; determining the position of the general location area on the image of the to-be-measured object according to the position of general location area recorded in the script; and determining a measurement area, the image in the measurement area is most similar to the standard image within the general location area.

Abstract: Improved correlation techniques employ data from forward (template-to-reference) and reverse (reference-to-template) correlation to identify valid correlation peaks, enforce symmetry in correlation peaks, and/or combine forward and reverse correlation data. In embodiments, these techniques eliminate or reduce rms noise in a recovered signal peak location by enforcing correlation peak symmetry. The forward and reverse correlation methods described herein may be used for validation of correlation peaks, detection of outlier data points and improved interpolation, such as for higher accuracy localization of a peak center with sub-pixel resolution.

Abstract: Apparatuses, computer media, and methods for altering a camera image, in which the source image may be angularly displaced from a camera image. A plurality of points on the camera image is located and a mesh is generated. Compensation information based on the displacement is determined, and a reshaped image is rendered from the mesh, the compensation information, and the camera image. The camera image is reshaped by relocating a proper subset of the points on the camera image. Deformation vectors are applied to corresponding points on the mesh using the compensation information. A correction factor is obtained from an angular displacement and a translation displacement of the source image from the camera image. The deformation factor is multiplied by the compensation factor to form a deformation vector to compensate for angular and translational displacements of the source image from the camera image.

Abstract: A system and a method for establishing an association for a plurality of images and a recording medium thereof are provided. The system includes a storage module and an association establishment module. The storage module is used for storing a plurality of images. Any two images having at least one common content form an associated image set. Each associated image set has an associated position information and an associated angle information, and each image in the same associated image set respectively has a photographing point with respect to a common content therein. The associated position information and the associated angle information are relative positions of and an included angle between photographing angles of the two photographing points with respect to the common content. The association establishment module establishes an association between the images according to the associated image sets and the associated position information and the associated angle information thereof.

Abstract: A method of re-locating an object in a sample is provided for a previously-scanned slide having determined objects each with corresponding stored coordinates and a stored image, the objects being mapped relative to each other. The slide is positioned on a microscope stage, stored images of the objects are visually displayed, and a target object is selected. The slide is moved to an estimated coordinate position, corresponding to the coordinates of the target object, and a field-of-view image of the sample is captured for comparison to the stored image of the target. If the target is in the image, an offset between actual coordinates of the located target and the stored coordinates of the corresponding object is determined. The slide is then moved, via the stage, from the estimated coordinate position, according to the offset, to center the target in the image. Associated systems and methods are also provided.

Abstract: An efficient technique is provided for determining a portion of a document corresponding to a captured image. Areas of a document in which the pattern is at least partially obscured are identified. A reference pixel in the image is selected, and an offset between the pixel and the pattern is determined. A pixel-by-pixel comparison is then made of the image with the document such that the reference pixel is only compared with locations in the document that are both within the identified areas and have the determined offset from the pattern. The comparison with the highest correspondence between the image pixels and the electronic document then identifies the position of the reference pixel relative to the electronic document.

Abstract: A method and algorithm for measuring the symmetry (SYM=total symmetry) of N points based on counting the number of “elementary symmetric recognition acts”, or having two distances d(A,B) and d(C,D) be equal within a given tolerance t. The same algorithm can be adapted to measure un-normalized positional entropy deficit (UPED) and positional entropy of N points. These parameters (SYM and UPED) come out almost the same for small occupation numbers (1<=k<=4). Here the occupation number k is the number of equal distances in the figure for a given value d. The algorithm can be incorporated into an imaging device, such as computer graphic programs or cameras, to solve problems of defect detection, say in gems, or object detection.

Abstract: An image processing apparatus includes: an image acquisition section which acquires an original image; a resolution conversion section which converts the resolution of the original image acquired by the image acquisition section and generates a plurality of reduced images having different resolutions; a detection section which processes by template matching the plurality of reduced images generated by the resolution conversion section and detects an area occupied by a picked-up image of a particular object corresponding to the template, from the reduced images; and a detection result processing section which detects the area occupied by the picked-up image of the particular object on the original image, by processing a detection result obtained by the detection section, the detection section detecting the area occupied by the picked-up image of the particular object by processing the plurality of reduced images in an order in which resolution sequentially varies on a step-by-step basis.

Abstract: A method identifying a ligature within a scanned document, the ligature including two or more touching characters. The two or more touching characters of the ligature are then compared to a plurality of prototypes to identify two or more matched prototypes. A synthetic ligature is then created based on the two or more matched prototypes.

Abstract: A template representative of an image of a human face is provided. At least one of the template and image data is rotated to adjust a relative angle between an original orientation of the template and an original orientation of the image data, so as to exclude an angle range including 180 degrees. It is examined a matching between a part of the image data and the template to identify a region in the image data containing an image of a human face. The image data is corrected in accordance with a condition of the image of the human face.

Abstract: Embodiments of the present invention relate to systems, methods and computer storage media for associating a known geographic location with a known identity. Feature matching, of at least two images, is performed in at least two iterations. The iterations are based on an orientation of feature vectors associated with points of interest in each image. A geometric model is applied to the matched points of interest to improve the matched pairs. Two images are identified as being related. As a result, the known geographic location is associated with the known identity. Additional embodiments include augmenting feature vectors with a coordinate location of a related point of interest based on a geometric model. Further, an exemplary embodiment includes an additional matching iteration based on the augmented feature vectors. In an exemplary embodiment, the feature matching utilizes a Scale-Invariant Feature Transform (SIFT).

Abstract: A film scanning method including the following steps is provided. Firstly, a film including an identification code and an image information area is provided, wherein the identification code is disposed on one side of the image information area along a first direction and has a first identification end and a second identification end along a second direction. Next, a location information of the identification code and a sequence information of the first identification end and the second identification end are checked and recorded. Lastly, the scanned image is adjusted along the first direction and the second direction respectively according to the location information and the sequence information. The invention provides the user with convenience in using a film scanning device without using additional elements.

Abstract: Embodiments described herein may operate to illuminate an image sensor array (ISA) used in, for example, a digital imager alternately using a first illuminator and a second illuminator laterally offset from the first illuminator with respect to a face of the ISA. A reduced illuminance level consistent with an existence of an occlusion may be sensed at an apparent occluded location on the ISA while the occlusion is illuminated with the first illuminator. If an illuminance level consistent with an existence of the occlusion is also sensed at the apparent occluded location while the occlusion is illuminated using the second illuminator, the occlusion may be identified as being located on the ISA. Otherwise, the occlusion may be identified as being located at a position anterior to the ISA, perhaps on a surface of a cover glass associated with the ISA.

Abstract: In an apparatus and method of transforming a block of data elements, the order of the data elements is transformed. The data elements are stored in an initial order in respective ones of first and second memory elements, each first memory element corresponding to a respective second memory element. The contents of all respective pairs of the first and second memory elements are compared. The data elements in the second memory elements are shifted to different ones of the second memory elements after each comparison while maintaining the initial order of the data elements. The shifts and comparisons are repeated until every data element has been compared with every other data element. The results of the comparisons are combined after each comparison to provide a result that can be used to order the data elements to a final order.

Abstract: A method and apparatus for inspecting the surface of articles, such as chips and wafers, for defects, includes a first phase of optically examining the complete surface of the article inspected at a relatively high speed and with a relatively low spatial resolution, and a second phase of optically examining with a relatively high spatial resolution only the suspected locations for the presence or absence of a defect therein.

Abstract: An optical element to be measured is irradiated with the light which has passed through an indicator, thereby to form an indicator image on an image pick-up surface. Maximum peak coordinates are specified and stored as a position of the indicator image relating to the first surface. Whether the second largest peak may be specified or not is determined. In case that this result is NO, the maximum peak indicator image is deleted, and maximum peak coordinates are specified again and stored as a position of the indicator image relating to the second surface.

Abstract: An approach to sub-pixel image registration involves determining parameters of an objective function from pixel values of a template image and of a target image. This objective function is defined on a bounded continuous domain of relative displacements of the template image and the target image, which corresponds to sub-pixel registration locations. This objective function is directly optimized without necessarily evaluating spatially interpolated values of either the template image or the target image to achieve a global optimum of the objective function in the bounded domain that provides the sub-pixel registration location. The approach can be used for tracking a template in a sequence of video frames.

Abstract: The present invention is directed to a method for automatic detection and segmentation of a target anatomical structure in received three dimensional (3D) volumetric medical images using a database of a set of volumetric images with expertly delineated anatomical structures. A 3D anatomical structure detection and segmentation module is trained offline by learning anatomical structure appearance using the set of expertly delineated anatomical structures. A received volumetric image for the anatomical structure of interest is searched online using the offline learned 3D anatomical structure detection and segmentation module.

Abstract: A method of automatically establishing the correct orientation of an image using facial information. This method is based on the exploitation of the inherent property of image recognition algorithms in general and face detection in particular, where the recognition is based on criteria that is highly orientation sensitive. By applying a detection algorithm to images in various orientations, or alternatively by rotating the classifiers, and comparing the number of successful faces that are detected in each orientation, one may conclude as to the most likely correct orientation. Such method can be implemented as an automated method or a semi automatic method to guide users in viewing, capturing or printing of images.

Abstract: Ultrasound imaging adapts as a function of a coherence factor. Various beamforming, image forming or image processing parameters are varied as a function of a coherence factor to improve detail resolution, contrast resolution, dynamic range or SNR. For example, a beamforming parameter such as the transmit or receive aperture size, apodization type or delay is selected to provide maximum coherence. Alternatively or additionally, an image forming parameter, such as the number of beams for coherent synthesis or incoherent compounding, is set as a function of the coherence factor. Alternatively or additionally an image processing parameter such as the dynamic range, linear or nonlinear video filter and/or linear or nonlinear map may also adapt as a function of the coherence factor.

Abstract: A system and method for imaging a document, and using a reference document to place pieces of the document in their correct relative position and resize such pieces in order to generate a single unified image, including the electronic capturing a document with one or multiple images using an imaging device, the performing of pre-processing of said images to optimize the results of subsequent image recognition, enhancement, and decoding, the comparing of said images against a database of reference documents to determine the most closely fitting reference document, and the applying of knowledge from said closely fitting reference document to adjust geometrically the orientation, shape, and size of said electronically captured images so that said images correspond as closely as possibly to said reference document.

Abstract: A non-contact method and apparatus for inspecting an object. At least one first image of the object on which an optical pattern is projected, taken from a first perspective is obtained. At least one second image of the object on which an optical pattern is projected, taken from a second perspective that is different to the first perspective is obtained. At least one common object feature in each of the at least one first and second images is then determined on the basis of an irregularity in the optical pattern as imaged in the at least one first and second images.

Abstract: An object-end positioning method is provided for positioning lower ends of two limbs of an object. In the method, a foreground processing is performed on an original image to obtain a foreground image. A number of turning points are obtained according to the foreground image, wherein connection of the turning points forms a polygonal curve. Each turning point is classified to be a convex or concave point according to an included angle between lines connecting the turning point to two adjacent turning points. A number of selected convex points and selected concave points are selected. Two of the selected convex points are selected as two temporary ends. Connection of the two temporary ends and a selected concave point located between the two temporary ends forms a triangle. Two positioning ends for positioning the lower ends of the two limbs of the object are determined according to the two temporary ends.

Abstract: A system for screening cargo containers is provided including an image generation device, an apparatus for screening cargo containers and an output module. The image generation device generates an image signal conveying information related to the contents of the cargo container. The apparatus receives the image signal and a list of objects conveying objects expected to be present in the cargo container. A processing unit processes the image signal in combination with the list of objects and a group of target images associated with objects to derive mismatch information data. The mismatch information data conveys at least one distinction between the list of objects and the information related to the contents of the cargo container conveyed by the image signal. Information conveying the mismatch information data is released and conveyed to a user of the system by an output module.

Abstract: The invention relates to a position determination method for a geodetic device having a distance and angle measuring functionality, such as a total station (1), a determination being made of the relative location of the geodetic device and reference points (2) marked with reflectors (P1-Pn) of a quantity of reference points, by measuring the distance (D1-Dn) and at least one angle (?i-?n, ?1-?n) from the geodetic device to the reference points as reference variables, the reference variables being determined in a device-based reference system. For the reference point quantity formed by the reference points (P1-Pn) and a reference point quantity of measurable reference points (A-G), the positions of which are known in an external reference system, common elements are identified, the relative location of the reference points (P1-Pn) being derived from the reference variables and the common elements being identified and associated based on the relative location of the reference points (P1-Pn).

Abstract: A light includes a light-producing inner tube, and an outer tube positioned around the light-producing inner tube; the light-producing inner tube has electrical terminals at two ends thereof, which sticks out of the outer tube; the outer tube has a light reflecting film on an outer side of a first portion thereof; an inner side of the first portion of the outer tube is processed so as to have a rough and lumpy surface, which can cause light produce by the light-producing inner tube to travel in all directions; the outer tube has a fluorescent layer on each of inner and outer sides of a second portion thereof, which make the second portion of the outer tube more pervious to light.

Abstract: The present invention is directed to diagnostic imaging of small pulmonary nodules. There are two main stages in the evaluation of pulmonary nodules from Computed Tomography (CT) scans: detection, in which the locations of possible nodules are identified, and characterization, in which a nodule is represented by measured features that may be used to evaluate the probability that the nodule is cancer. Currently, the most useful prediction feature is growth rate, which requires the comparison of size estimates from two CT scans recorded at different times. The present invention includes methods for detection and feature extraction for size characterization. The invention focuses the analysis of small pulmonary nodules that are less than 1 centimeter in size, but is also suitable for larger nodules as well.

Abstract: Method and apparatus for producing an image containing depth information is provided. The method detects radiation emanating from a scene and forms at least two images of the scene at different planes. Each image contains a set of intensity data values. A variation of the data values is obtained so that two sets of intensity variances are obtained from the data values, and the intensity variance data is processed to obtain depth information. The depth information is coded so as to identify different depth information in the image data.

Abstract: Methods, systems and apparatus, including computer program products, for processing electronic images. An electronic image is transformed to generate a transformed image according to a first coordinate transformation. The transformed image is filtered, and a second coordinate transformation is applied to the filtered image to align the filtered image with an accumulation array that includes multiple accumulation elements. Each accumulation element is updated based on a respective value in the aligned image. The operations of generating a transformed image according to a first transformation, filtering the transformed image, applying a second transformation and updating each accumulation element are iterated for one or more further first coordinate transformations. These techniques can be implemented to detect features in the image using a graphics processing unit.

Abstract: An image forming method includes receiving an image, detecting a text area from the image, transforming the detected text area into a binary image and calculating an asymmetry parameter of the binary image, and detecting orientation of the image based on the calculated asymmetry parameter.

Abstract: Up and down directions of an image are to be precisely judged without a special equipment installed in an image pickup device. An object candidate detecting means detects object candidates from an input image and their angles in the input image. A similarity calculation means calculate the degree of similarity between each detected object candidate and each object stored in advance. An input image angle calculating means judges up and down directions of the input image based on the calculated similarity of each object candidate and the angle of the input image. The input image angle calculating means carries out weighting for the angle of each object candidate in the input image based on its similarity and calculates slant angles with respect to the up and down directions of the input image by using the weighted angles.

Abstract: System and method for characterizing vision systems. A multi-dimensional condition space is provided, each dimension representing a respective condition axis, where each point in the condition space specifies a set of conditions under which a vision system may operate. An image is provided. The condition space is sampled according to a pseudo-random sequence, e.g., a low-discrepancy sequence, to determine a plurality of test conditions usable to characterize the vision system, where each test condition corresponds to a respective set of conditions. A plurality of test images corresponding to the plurality of test conditions are generated based on the image, e.g., by applying image processing functions to the image that simulate the test conditions. A vision inspection is performed on each of the plurality of test images to generate respective test results, and the test results are analyzed to determine conditions under which the vision system operates correctly.

Abstract: In an image recognition apparatus, feature point extraction sections and extract feature points from a model image and an object image. Feature quantity retention sections extract a feature quantity for each of the feature points and retain them along with positional information of the feature points. A feature quantity comparison section compares the feature quantities with each other to calculate the similarity or the dissimilarity and generates a candidate-associated feature point pair having a high possibility of correspondence. A model attitude estimation section repeats an operation of projecting an affine transformation parameter determined by three pairs randomly selected from the candidate-associated feature point pair group onto a parameter space. The model attitude estimation section assumes each member in a cluster having the largest number of members formed in the parameter space to be an inlier.

Abstract: Aspects of the present invention are related to systems and methods for determining the orientation of an electronic document image.

Abstract: An image retrieval apparatus is disclosed that is capable of extracting a similar image similar to an input image and includes a unit to acquire input image data, a unit to generate a plurality of processed image data a unit to generate a plurality of extraction condition data that become conditions for extracting the similar image from the retrieval target image data, a unit to extract the similar image from the retrieval target image data based on each of the generated plurality of extraction condition data, and a unit to generate extraction result display data to display the extracted similar image, in which the extraction result display data generation unit generates the extraction result display data so that the extracted similar image is associated and displayed with the extraction condition data used as the conditions to extract the similar image.

Abstract: Systems and methods for pacing and error monitoring of a manual page turning operator of a system for capturing images of a bound document are disclosed. The system includes a speaker for playing music having a tempo and a controller for controlling the tempo based on an imaging rate and/or an error rate. The operator is influenced by the music tempo to capture images at a given rate. Alternative or in addition to audio, error detection may be implemented using OCR to determine page numbers to track page sequence and/or a sensor to detect errors such as object intrusion in the image frame and insufficient light. The operator may be alerted of an error with audio signals and signaled to turn back a certain number of pages to be recaptured. When music is played, the tempo can be adjusted in response to the error rate to reduce operator errors and increase overall throughput of the image capturing system. The tempo may be limited to a maximum tempo based on the maximum image capture rate.

Abstract: Improved correlation techniques employ data from forward (template-to-reference) and reverse (reference-to-template) correlation to identify valid correlation peaks, enforce symmetry in correlation peaks, and/or combine forward and reverse correlation data. In embodiments, these techniques eliminate or reduce rms noise in a recovered signal peak location by enforcing correlation peak symmetry. The forward and reverse correlation methods described herein may be used for validation of correlation peaks, detection of outlier data points and improved interpolation, such as for higher accuracy localization of a peak center with sub-pixel resolution.

Abstract: A pattern alignment method performs alignment of the comparison source pattern or the comparison target pattern that has been subjected to the angle-scale conversion with the comparison source pattern. Angular deviations and scale factors between the comparison source pattern and the comparison target pattern are computed separately, after angle and scale conversion, the measured template matching is performed. Therefore, parallel-displacement alignment can be made faster and precise alignment is possible. Template matching processing can be minimized, and aligning can be performed precisely and rapidly.

Abstract: The invention relates to a method for providing corrected data in order to generate a model of a monitoring area which is located in the respective visual range of at least two opto-electronic sensors for determining the position of detected objects, based on the amounts of raw data elements corresponding to object points in said monitoring area, said amounts of raw data elements being respectively detected by one of the sensors when the visual range is sensed and associated therewith, and the amounts of raw data elements from various sensors which are temporally linked to each other forming a group. The raw data elements corresponding to said amounts respectively comprise at least the coordinates of object points detected by the associated sensor in relation to the position of the detecting sensor.

Abstract: A method for detecting target objects in a three dimensional (3D) image volume of an anatomical structure is disclosed. A set of candidate locations in the image volume are obtained. For each candidate location, sub-volumes of at least two different scales are cropped out. Each sub-volume comprises a plurality of voxels. For each of the sub-volumes, each sub-volume is rotated in at least two different orientations. A shape classifier is applied to each sub-volume. If the voxels in the sub-volume pass the shape classifier, a gradient direction is computed for the voxels. If the gradient direction for the voxels is one of a predefined orientation, a probability classifier is applied to the voxels. A probability measure computed by the probability classifier as a confidence measure is used for the sub-volume. If the confidence measure is above a predetermined threshold value, the sub-volume is determined to contain the target object.

Abstract: A system and method for imaging an object, and using reference templates to recognize and enhance object image, including the identification of a template for a specific area of a target object to which images of the object may be compared, the use of the camera on a wireless device to image the target object, comparison of the images of the object within the specific area of the object to the template for that area of the object, identification of the image of the object from the comparison of the image to the template for the specific area of the object, and the storage of the template and the identified image on a data server.

Abstract: A technique is disclosed for determining a portion of a document corresponding to a captured image. A user employs a pen to create a stroke in a document, and images are captured by a camera mounted on the pen. The locations of some of the images are determined by, e.g., analyzing a pattern on the document captured by the image or by a pixel-by-pixel comparison of the image with the document. The locations of other images are determined by segmenting the sequence of images into groups corresponding to the shape of the stroke. Information relating to a located image in a segment is employed to determine the position of an unlocated image in the segment. This determined position is used for obtaining further information that may be used to determine the position of another unlocated image in the segment, and so on, until the segment is finished.