Search results for "Digital image"

Plywood Jig—A New Technique for Root Canal Curvature Measurement

2021

The successful outcome of endodontic treatment is dependent on complete cleaning, shaping as well as three dimensional obturation of the root canal system. A conventional radiograph is a two-dimensional replication of a three-dimensional object and does not provide any conclusive evidence for canal curvatures. An accurate knowledge of the tooth anatomy and curvature is essential to avoid procedural errors. 100 freshly extracted human teeth were used in this study. Digital images were obtained using the plywood JIG and Schneider’s technique. These images were analyzed using the VixWin Pro digital image analyzing software (Gendex system). Statistical analysis was done using paired t test. The…

Investigation of the Thermomechanical Response of Cyclically Loaded NiTi Alloys by Means of Temperature Frequency Domain Analyses

2021

Nickel–Titanium (NiTi) shape memory alloys subjected to cyclic loading exhibit reversible temperature changes whose modulation is correlated with the applied load. This reveals the presence of reversible thermomechanical heat sources activated by the applied stresses. One such source is the elastocaloric effect, accounting for the latent heat of Austenite–Martensite phase transformation. It is, however, observed that when the amplitude of cyclic loads is not sufficient to activate or further propagate this phase transformation, the material still exhibits a strong cyclic temperature modulation. The present work investigates the thermomechanical behaviour of NiTi under such low-amplitude cyc…

Copy-move Forgery Detection via Texture Description

2010

Copy-move forgery is one of the most common type of tampering in digital images. Copy-moves are parts of the image that are copied and pasted onto another part of the same image. Detection methods in general use block-matching methods, which first divide the image into overlapping blocks and then extract features from each block, assuming similar blocks will yield similar features. In this paper we present a block-based approach which exploits texture as feature to be extracted from blocks. Our goal is to study if texture is well suited for the specific application, and to compare performance of several texture descriptors. Tests have been made on both uncompressed and JPEG compressed image…

Improved Liquid Crystal Thermography by Using True-Colour Image Processing Technology

2002

No abstract available

The Use of Thermochromic Liquid Crystals and Image Processing for Technical and Biomedical Thermography

1999

Palermo: Virtual urban reconfiguration of some ancient squares and quarters

2013

The representation area is nowaday called upon to face new challenges for new computer technologies that have developed over the last few years. Visual communication and multimedia language experienced a radical change: representation and visualization, thought and image are based on the branch of communication and therefore on the trasmission of knowledge that cannot be separated from the interdisciplinarity. Digital imagery challenges more and more analog imagery, creating a scene that is independent from the constructed reality and sometimes reaching to overlap and merge with it: therefore the representation is no longer just a repetition of the real, but becomes itself an autonomous rea…

What Conclusions does Rapid Image Classification by Eye Movements Provide for Machine Vision?

2008

Human ability to rapidly classify images of natural objects has been a matter of study for more than a decade. Recently eye movements have been exploited as a behavioural response, which has lead to alternative hypotheses of natural image processing. In this research, twelve volunteers made a movement towards a briefly displayed digital image if it was an animal, and a movement away otherwise. In both cases, the average response time was more than 400 milliseconds.

Phase-shifting Gabor holography.

2009

We present a modified Gabor-like setup able to recover the complex amplitude distribution of the object wavefront from a set of inline recorded holograms. The proposed configuration is characterized by the insertion of a condenser lens and a spatial light modulator (SLM) into the classical Gabor configuration. The phase shift is introduced by the SLM that modulates the central spot (dc term) in an intermediate plane, without an additional reference beam. Experimental results validate the proposed method and produce superior results to the Gabor method.

Off-axis digital holographic multiplexing for rapid wavefront acquisition and processing

2020

Off-axis holographic multiplexing involves capturing several complex wavefronts, each encoded into off-axis holograms with different interference fringe orientations, simultaneously, with a single camera acquisition. Thus, the multiplexed off-axis hologram can capture several wavefronts at once, where each one encodes different information from the sample, using the same number of pixels typically required for acquiring a single conventional off-axis hologram encoding only one sample wavefront. This gives rise to many possible applications, with focus on acquisition of dynamic samples, with hundreds of scientific papers already published in the last decade. These include field-of-view multi…

Superresolved common-path phase-shifting digital inline holographic microscopy using a spatial light modulator.

2012

Common-path phase-shifting lensless holographic microscopy has been recently proposed as a novel approach capable of high numerical aperture imaging in a lensless digital inline holographic microscopy layout [Opt. Lett.35, 3919 (2010)]. Here we present proof-of-concept validation for improving the resolution limit imposed by diffraction in such a setup. This is accomplished by shifting the phase lens displayed at the spatial light modulator, which moves the illumination point source to different off-axis positions. For each off-axis position, a set of inline phase-shifted holograms are recorded by the digital sensor and stored at the computer’s memory for later digital postprocessing. As a …