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Patrick Eoghan Denny

Other affiliations: East Sussex County Council
Bio: Patrick Eoghan Denny is an academic researcher from Valeo. The author has contributed to research in topics: Computer science & Image processing. The author has an hindex of 11, co-authored 90 publications receiving 726 citations. Previous affiliations of Patrick Eoghan Denny include East Sussex County Council.


Papers
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Journal ArticleDOI
TL;DR: A method is presented by which the lens curve of a fish-eye camera can be extracted using well-founded assumptions and perspective methods and several of the models from the literature are examined against this empirically derived curve.
Abstract: The majority of computer vision applications assumes that the camera adheres to the pinhole camera model. However, most optical systems will introduce undesirable effects. By far, the most evident of these effects is radial lensing, which is particularly noticeable in fish-eye camera systems, where the effect is relatively extreme. Several authors have developed models of fish-eye lenses that can be used to describe the fish-eye displacement. Our aim is to evaluate the accuracy of several of these models. Thus, we present a method by which the lens curve of a fish-eye camera can be extracted using well-founded assumptions and perspective methods. Several of the models from the literature are examined against this empirically derived curve.

123 citations

Journal ArticleDOI
TL;DR: Although wide- angle optics provide greater fields of view, they also introduce undesirable effects, such as radial distortion, tangential distortion and uneven illumination, which have the potential to make objects difficult for the vehicle driver to recognise and, thus, potentially have a greater risk of accident.
Abstract: The development of electronic vision systems for the automotive market is a strongly growing field, driven in particular by customer demand to increase the safety of vehicles both for drivers and for other road users, including vulnerable road users (VRUs), such as pedestrians. Customer demand is matched by legislative developments in a number of key automotive markets; for example Europe, Japan and the US are in the process of introducing legislation to aid in the prevention of fatalities to VRUs, with emphasis on the use of vision systems. The authors discuss some of the factors that motivate the use of wide-angle and fish-eye camera technologies in vehicles. The authors describe the benefits of using wide-angle lens camera systems to display areas of a vehicle's surroundings that the driver would, otherwise, be unaware of (i.e. a vehicle's blind-zones). However, although wide- angle optics provide greater fields of view, they also introduce undesirable effects, such as radial distortion, tangential distortion and uneven illumination. These distortions have the potential to make objects difficult for the vehicle driver to recognise and, thus, potentially have a greater risk of accident. The authors describe some of the methods that can be employed to remove these unwanted effects, and digitally convert the distorted image to the ideal and intuitive rectilinear pin-hole model.

112 citations

Journal ArticleDOI
TL;DR: A method to photogrammetrically estimate the intrinsic and extrinsic parameters of fish-eye cameras using the properties of equidistance perspective, particularly vanishing point estimation, with the aim of providing a rectified image for scene viewing applications.
Abstract: In this paper, we describe a method to photogrammetrically estimate the intrinsic and extrinsic parameters of fish-eye cameras using the properties of equidistance perspective, particularly vanishing point estimation, with the aim of providing a rectified image for scene viewing applications. The estimated intrinsic parameters are the optical center and the fish-eye lensing parameter, and the extrinsic parameters are the rotations about the world axes relative to the checkerboard calibration diagram.

80 citations

Proceedings ArticleDOI
18 Jun 2008
TL;DR: Methods of correcting radial and other distortions for fish-eye cameras are reviewed and discussed and the effect of these methods on a test image exhibiting multiple types of distortion is illustrated.
Abstract: The majority of computer vision applications assume the pin-hole camera model. However, most optics will introduce some undesirable effects, rendering the assumption of the pin-hole camera model invalid. This is particularly evident in cameras with wide fields-of-view. The aim of distortion correction is, therefore, to transform the distorted view of wide-angle cameras to the pin-hole perspective view. Fish-eye cameras are those with "super-wide" fields-of-view, e.g. those cameras with fields-of-view of up to 180 degrees. However, these lenses exhibit severe forms of distortion. The most evident of these is radial distortion, but several other distortions, such as uneven illumination and inaccurate estimation of the centre of distortion, should also be considered when using a fish-eye camera. In this paper, we review and discuss methods of correcting radial and other distortions for fish-eye cameras and illustrate the effect of these methods on a test image exhibiting multiple types of distortion.

64 citations

Patent
31 Oct 2006
TL;DR: In this article, an image vision system is used to calibrate two cameras mounted on respective side rear view mirror housings of a motor vehicle for correcting for offset of the cameras from ideal positions relative to the vehicle.
Abstract: An image vision system (8) for calibrating two cameras (17) mounted on respective side rear view mirror housings (5) of a motor vehicle (1) for correcting for offset of the cameras (17) from ideal positions relative to the vehicle (1). The cameras (17) capture plan view images of the ground on respective opposite sides of the vehicle for display as images (10,11) along with a plan view image (14) of the vehicle (1) on an in-vehicle visual display unit (13), for assisting a driver parking or manoeuvring the vehicle (1 ) in a confined space. Calibration of the cameras (17) is carried out as the side mirror housings (5) are swivelled from a rest position to an operative position in response to activation of the ignition system of the vehicle (1). The calibration requires determining the offset of the actual position of a reference point (34) on the vehicle (1 ) captured in an image by the corresponding camera (17) from the ideal position of the reference point (34a) in an ideal image frame. A transformation function which is expressed as two third order polynomial expressions for the X and Y co-ordinates is produced based on the computed offset for the X and Y co-ordinates of the reference point (34), and a look-up table is then prepared from the two polynomial expressions which indicates the position at which the pixels in the subsequently captured image frames should be located in corresponding output image frames for display on the visual display unit (13) with correction for offset of the corresponding camera (17).

61 citations


Cited by
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Patent
16 Jan 2012
TL;DR: In this article, the camera is disposed at an interior portion of a vehicle equipped with the vehicular vision system, where the camera one of (i) views exterior of the equipped vehicle through the windshield of the vehicle and forward of the equipment and (ii) views from the windshield into the interior cabin of the equipments.
Abstract: A vehicular vision system includes a camera having a lens and a CMOS photosensor array having a plurality of photosensor elements. The camera is disposed at an interior portion of a vehicle equipped with the vehicular vision system. The camera one of (i) views exterior of the equipped vehicle through the windshield of the equipped vehicle and forward of the equipped vehicle and (ii) views from the windshield of the equipped vehicle into the interior cabin of the equipped vehicle. A control includes an image processor that processes image data captured by the photosensor array. The image processor processes captured image data to detect an object viewed by the camera. The photosensor array is operable at a plurality of exposure periods and at least one exposure period of the plurality of exposure periods is dynamically variable.

576 citations

Journal ArticleDOI
TL;DR: This survey provides a general overview of classical algorithms and recent progresses in the field of perceptual image quality assessment and describes the performances of the state-of-the-art quality measures for visual signals.
Abstract: Perceptual quality assessmentplays a vital role in the visual communication systems owing to theexistence of quality degradations introduced in various stages of visual signalacquisition, compression, transmission and display.Quality assessment for visual signals can be performed subjectively andobjectively, and objective quality assessment is usually preferred owing to itshigh efficiency and easy deployment. A large number of subjective andobjective visual quality assessment studies have been conducted during recent years.In this survey, we give an up-to-date and comprehensivereview of these studies.Specifically, the frequently used subjective image quality assessment databases are firstreviewed, as they serve as the validation set for the objective measures.Second, the objective image quality assessment measures are classified and reviewed according to the applications and the methodologies utilized in the quality measures.Third, the performances of the state-of-the-artquality measures for visual signals are compared with an introduction of theevaluation protocols.This survey provides a general overview of classical algorithms andrecent progresses in the field of perceptual image quality assessment.

281 citations

Patent
11 Sep 2008
TL;DR: In this article, a vehicular imaging system includes an imaging device that is part of an exterior rearview mirror assembly and having a field of view rearward and/or sideward of the vehicle.
Abstract: A vehicular imaging system includes an imaging device that is part of an exterior rearview mirror assembly and having a field of view rearward and/or sideward of the vehicle. A control processes captured image data utilizing edge detection. Responsive at least in part to the processing, the control determines objects of interest present in the field of view of the imaging device. Objects of interest determined to be present in the field of view include (i) a vehicle that is rearward and/or sideward of the vehicle, (ii) a headlight of a vehicle that is rearward and/or sideward of the vehicle, (iii) a bicycle that is rearward and/or sideward of the vehicle, and/or (iv) a bicycle rider that is rearward and/or sideward of the vehicle. Responsive at least in part to the processing of captured image data, a driver of the vehicle is alerted to a hazardous condition.

274 citations

Book
05 Jan 2011
TL;DR: This survey gives an overview of image acquisition methods used in computer vision and especially, of the vast number of camera models that have been proposed and investigated over the years, where it tries to point out similarities between different models.
Abstract: This survey is mainly motivated by the increased availability and use of panoramic image acquisition devices, in computer vision and various of its applications. Different technologies and different computational models thereof exist and algorithms and theoretical studies for geometric computer vision ("structure-from-motion") are often re-developed without highlighting common underlying principles. One of the goals of this survey is to give an overview of image acquisition methods used in computer vision and especially, of the vast number of camera models that have been proposed and investigated over the years, where we try to point out similarities between different models. Results on epipolar and multi-view geometry for different camera models are reviewed as well as various calibration and self-calibration approaches, with an emphasis on non-perspective cameras. We finally describe what we consider are fundamental building blocks for geometric computer vision or structure-from-motion: epipolar geometry, pose and motion estimation, 3D scene modeling, and bundle adjustment. The main goal here is to highlight the main principles of these, which are independent of specific camera models.

234 citations