Stereo vision technology for object measurement. [Proceedings of SPIE 5011, 307 (2003)]. Lyndon N... more Stereo vision technology for object measurement. [Proceedings of SPIE 5011, 307 (2003)]. Lyndon N. Smith, Melvyn L. Smith. Abstract. This paper is concerned with research into machine vision techniques for measuring the size and shape of objects. ...
ABSTRACT In order to achieve an early detection of skin cancers, various state-of-the-art imaging... more ABSTRACT In order to achieve an early detection of skin cancers, various state-of-the-art imaging modalities have been investigated from optical, impedance, biomechanical and physiological perspectives to find out the potential biomarkers. However multilayered skin microstructure and a wide spectrum of dynamical chromophores embedded underneath skin make it very challenging to quantify this mostly accessible, but very complex and heterogeneous largest organ of the human body. Rather than concentrating on characterizing those internal features in a microscopic level, both lesion reflectance (colour) and 3D geometry have been suggested to recover through a relative easy and cost effective way towards an improved diagnosis of melanoma. The reflectance recovered can be used as a good replacement for conventional photograph for the measurement of the ABCD criteria, while the geometry of lesion surface provides extra dimension for characterizing the topography disruption of lesion region. As both the reflectance and geometry of skin surface generally reflect the growth of chromophore cells under the skin, any external abnormalities indicating the change of skin conditions must accompany with some irregular evolvement and change with these cells. For example, a blurred and asymmetrical border possibly reveals an abnormal growth of melanocytes in the horizontal phase; whiles 3D surface indentations and protrusions accompanying variegated pigmentation may indicate an aggressive penetration of melanin into the dermal layer. We compared new features derived from reflectance and geometrical information with those traditional ones and demonstrated their significance as additional clues for melanoma diagnosis.
Computer-assisted diagnosis (CAD) of malignant melanoma (MM) has been advocated to help clinician... more Computer-assisted diagnosis (CAD) of malignant melanoma (MM) has been advocated to help clinicians to achieve a more objective and reliable assessment. However, conventional CAD systems examine only the features extracted from digital photographs of lesions. Failure to incorporate patients' personal information constrains the applicability in clinical settings. To develop a new CAD system to improve the performance of automatic diagnosis of melanoma, which, for the first time, incorporates digital features of lesions with important patient metadata into a learning process. Thirty-two features were extracted from digital photographs to characterize skin lesions. Patients' personal information, such as age, gender and, lesion site, and their combinations, was quantified as metadata. The integration of digital features and metadata was realized through an extended Laplacian eigenmap, a dimensionality-reduction method grouping lesions with similar digital features and metadata into the same classes. The diagnosis reached 82.1% sensitivity and 86.1% specificity when only multidimensional digital features were used, but improved to 95.2% sensitivity and 91.0% specificity after metadata were incorporated appropriately. The proposed system achieves a level of sensitivity comparable with experienced dermatologists aided by conventional dermoscopes. This demonstrates the potential of our method for assisting clinicians in diagnosing melanoma, and the benefit it could provide to patients and hospitals by greatly reducing unnecessary excisions of benign naevi. This paper proposes an enhanced CAD system incorporating clinical metadata into the learning process for automatic classification of melanoma. Results demonstrate that the additional metadata and the mechanism to incorporate them are useful for improving CAD of melanoma.
AbstractEstablishing the accuracy of optical-sensing systems for tools used in surgical procedur... more AbstractEstablishing the accuracy of optical-sensing systems for tools used in surgical procedures is an essential and non-trivial task. This paper shows that an optical-tracking system may be regarded as a cooperative system in that its accuracy is related not only to the optical-...
Palmprints are of considerable interest as a reliable biometric, since they offer significant adv... more Palmprints are of considerable interest as a reliable biometric, since they offer significant advantages, such as greater user acceptance than fingerprint or iris recognition. 2D systems can be spoofed by a photograph of a hand; however, 3D avoids this by recovering and analysing 3D textures and profiles. 3D palmprints can also be captured in a contactless manner, which is critical for ensuring hygiene (something that is particularly important in relation to pandemics such as COVID-19), and ease of use. The gap in prior work, between low resolution wrinkle studies and high-resolution palmprint recognition, is bridged here using high-resolution non-contact photometric stereo. A camera and illuminants are synchronised with image capture to recover high-definition 3D texture data from the palm, which are then analysed to extract ridges and wrinkles. This novel low-cost approach, which can tolerate distortions inherent to unconstrained contactless palmprint acquisition, achieved a 0.1% equ
We present and experimentally demonstrate the potential effectiveness of a photometric stereo bas... more We present and experimentally demonstrate the potential effectiveness of a photometric stereo based high resolution system for capturing 3D handprints using visible light sources. The sub-surface vascular structures are also enhanced through the use of near-infrared light sources which offers a potentially useful technique to increase system security. In contrast to existing systems which locate specific minutiae features of a fingerprint, we propose to use a global/holistic approach based on the spatial frequencies of the handprint, and preliminary results on 11 subjects show the high potential of this approach for contactless biometric identification purposes
Stereo vision technology for object measurement. [Proceedings of SPIE 5011, 307 (2003)]. Lyndon N... more Stereo vision technology for object measurement. [Proceedings of SPIE 5011, 307 (2003)]. Lyndon N. Smith, Melvyn L. Smith. Abstract. This paper is concerned with research into machine vision techniques for measuring the size and shape of objects. ...
ABSTRACT In order to achieve an early detection of skin cancers, various state-of-the-art imaging... more ABSTRACT In order to achieve an early detection of skin cancers, various state-of-the-art imaging modalities have been investigated from optical, impedance, biomechanical and physiological perspectives to find out the potential biomarkers. However multilayered skin microstructure and a wide spectrum of dynamical chromophores embedded underneath skin make it very challenging to quantify this mostly accessible, but very complex and heterogeneous largest organ of the human body. Rather than concentrating on characterizing those internal features in a microscopic level, both lesion reflectance (colour) and 3D geometry have been suggested to recover through a relative easy and cost effective way towards an improved diagnosis of melanoma. The reflectance recovered can be used as a good replacement for conventional photograph for the measurement of the ABCD criteria, while the geometry of lesion surface provides extra dimension for characterizing the topography disruption of lesion region. As both the reflectance and geometry of skin surface generally reflect the growth of chromophore cells under the skin, any external abnormalities indicating the change of skin conditions must accompany with some irregular evolvement and change with these cells. For example, a blurred and asymmetrical border possibly reveals an abnormal growth of melanocytes in the horizontal phase; whiles 3D surface indentations and protrusions accompanying variegated pigmentation may indicate an aggressive penetration of melanin into the dermal layer. We compared new features derived from reflectance and geometrical information with those traditional ones and demonstrated their significance as additional clues for melanoma diagnosis.
Computer-assisted diagnosis (CAD) of malignant melanoma (MM) has been advocated to help clinician... more Computer-assisted diagnosis (CAD) of malignant melanoma (MM) has been advocated to help clinicians to achieve a more objective and reliable assessment. However, conventional CAD systems examine only the features extracted from digital photographs of lesions. Failure to incorporate patients' personal information constrains the applicability in clinical settings. To develop a new CAD system to improve the performance of automatic diagnosis of melanoma, which, for the first time, incorporates digital features of lesions with important patient metadata into a learning process. Thirty-two features were extracted from digital photographs to characterize skin lesions. Patients' personal information, such as age, gender and, lesion site, and their combinations, was quantified as metadata. The integration of digital features and metadata was realized through an extended Laplacian eigenmap, a dimensionality-reduction method grouping lesions with similar digital features and metadata into the same classes. The diagnosis reached 82.1% sensitivity and 86.1% specificity when only multidimensional digital features were used, but improved to 95.2% sensitivity and 91.0% specificity after metadata were incorporated appropriately. The proposed system achieves a level of sensitivity comparable with experienced dermatologists aided by conventional dermoscopes. This demonstrates the potential of our method for assisting clinicians in diagnosing melanoma, and the benefit it could provide to patients and hospitals by greatly reducing unnecessary excisions of benign naevi. This paper proposes an enhanced CAD system incorporating clinical metadata into the learning process for automatic classification of melanoma. Results demonstrate that the additional metadata and the mechanism to incorporate them are useful for improving CAD of melanoma.
AbstractEstablishing the accuracy of optical-sensing systems for tools used in surgical procedur... more AbstractEstablishing the accuracy of optical-sensing systems for tools used in surgical procedures is an essential and non-trivial task. This paper shows that an optical-tracking system may be regarded as a cooperative system in that its accuracy is related not only to the optical-...
Palmprints are of considerable interest as a reliable biometric, since they offer significant adv... more Palmprints are of considerable interest as a reliable biometric, since they offer significant advantages, such as greater user acceptance than fingerprint or iris recognition. 2D systems can be spoofed by a photograph of a hand; however, 3D avoids this by recovering and analysing 3D textures and profiles. 3D palmprints can also be captured in a contactless manner, which is critical for ensuring hygiene (something that is particularly important in relation to pandemics such as COVID-19), and ease of use. The gap in prior work, between low resolution wrinkle studies and high-resolution palmprint recognition, is bridged here using high-resolution non-contact photometric stereo. A camera and illuminants are synchronised with image capture to recover high-definition 3D texture data from the palm, which are then analysed to extract ridges and wrinkles. This novel low-cost approach, which can tolerate distortions inherent to unconstrained contactless palmprint acquisition, achieved a 0.1% equ
We present and experimentally demonstrate the potential effectiveness of a photometric stereo bas... more We present and experimentally demonstrate the potential effectiveness of a photometric stereo based high resolution system for capturing 3D handprints using visible light sources. The sub-surface vascular structures are also enhanced through the use of near-infrared light sources which offers a potentially useful technique to increase system security. In contrast to existing systems which locate specific minutiae features of a fingerprint, we propose to use a global/holistic approach based on the spatial frequencies of the handprint, and preliminary results on 11 subjects show the high potential of this approach for contactless biometric identification purposes
Uploads
Papers by Melvyn Smith