Near-field photometric stereo using a ring-light imaging device

A quantification of skin surface is one of challenging problem which is required in skin health assessment and efficacy evaluation of cosmetic products. Due to limitations of direct visual assessment of skin microscopic topography, an optical dermastocopy is commonly used as skin imaging device to magnify skin topography based on a white light reflection. The limitation of this method is its poor spatial resolution to quantify skin topography. In this paper, a skin imaging based on photometric stereo is proposed to visualize microscopic topography of human skin. The prototype was developed based on modification of illumination source system on the digital microscope. The illumination system consists of 6 and 9 super-bright LED. Additional electronic circuit was integrated with illumination system in order to control LED so that it can light successively. After that, set of images acquired in different angle of illumination was recorded. All images will be reconstructed using software to obtain stereo images, which shows the depth of the surface. Implementation on skin surface profile performed on three test areas: the back of the hand and knuckle creases. Based on qualitative analysis, our proposed scheme of skin imaging based on photometric stereo is promising for surface profile measurement and imaging of the skin.

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Microwave Imaging for Breast Cancer Detection

10.5772/intechopen.97313 ◽

2021 ◽

Author(s):

Yoshihiko Kuwahara

Keyword(s):

Soft Tissues ◽

Near Field ◽

Microwave Imaging ◽

Breast Cancer Detection ◽

Confocal Imaging ◽

X Rays ◽

Imaging Device ◽

Actual Equipment ◽

Hardware Configuration ◽

Imaging Algorithms

Microwave imaging (MI) is characterized by no exposure, stronger contrast between soft tissues than X-rays and ultrasound, and a smaller device scale. This chapter describes the electrical properties of the breast tissue that underlie MI, and then outlines the MI hardware configuration and three imaging algorithms: confocal imaging, scattering tomography, and near-field holography. After that, we will introduce the actual equipment and experimental results using the three imaging algorithms. Finally, we will summarize the challenges of realizing a medical imaging device using MI.

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Near-field optical microscopy with video signal processor to apply a CCD imaging device as a variable area photo-sensor for improving operability and spectrum mode imaging

Ultramicroscopy ◽

10.1016/s0304-3991(02)00085-2 ◽

2002 ◽

Vol 91 (1-4) ◽

pp. 83-88

Author(s):

H Muramatsu ◽

J.M Kim

Keyword(s):

Optical Microscopy ◽

Near Field ◽

Video Signal ◽

Imaging Device ◽

Ccd Imaging ◽

Photo Sensor ◽

Signal Processor

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Semi-Calibrated Near Field Photometric Stereo

2017 IEEE Conference on Computer Vision and Pattern Recognition (CVPR) ◽

10.1109/cvpr.2017.481 ◽

2017 ◽

Cited By ~ 11

Author(s):

Fotios Logothetis ◽

Roberto Mecca ◽

Roberto Cipolla

Keyword(s):

Near Field ◽

Photometric Stereo

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Ultimate resolution and information in electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086787 ◽

1991 ◽

Vol 49 ◽

pp. 496-497

Author(s):

D. Van Dyck

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Transfer Function ◽

Information Transfer ◽

Communication Channel ◽

Structural Information ◽

Information Rate ◽

Noise Power ◽

Signal Power ◽

Imaging Device

An (electron) microscope can be considered as a communication channel that transfers structural information between an object and an observer. In electron microscopy this information is carried by electrons. According to the theory of Shannon the maximal information rate (or capacity) of a communication channel is given by C = B log2 (1 + S/N) bits/sec., where B is the band width, and S and N the average signal power, respectively noise power at the output. We will now apply to study the information transfer in an electron microscope. For simplicity we will assume the object and the image to be onedimensional (the results can straightforwardly be generalized). An imaging device can be characterized by its transfer function, which describes the magnitude with which a spatial frequency g is transferred through the device, n is the noise. Usually, the resolution of the instrument ᑭ is defined from the cut-off 1/ᑭ beyond which no spadal information is transferred.

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