Pintavirooj, Chuchart

Preferred name

Alternative Name

Pintavirooj, C.

Pintavirooj, Chuchat

Main Affiliation

School of Engineering

chuchart.pi@kmitl.ac.th

Now showing 1 - 10 of 10

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3D modeling from multiple projections: Parallel-beam to helical cone-beam trajectory
(2005-12-01)
Narkbuakaew, W.
;
Pintavirooj, C.
;
Withayachumnankul, W.
;
Sangworasil, M.
;
Taertulakarn, S.
Tomographic imaging is a technique for exploration of a cross-section of an inspected object without destruction. Normally, the input data, known as the projections, are gathered by repeatedly radiating coherent waveform through the object in a number of viewpoints, and receiving by an array of corresponding detector in the opposite position. In this research, as a replacement of radiographs, the series of photographs taken around the opaque object under the ambient light is completely served as the projections. The purposed technique can be adopted with various beam geometry including parallel-beam, cone-beam and spiral cone-beam geometry. From the process of tomography, the outcome is the stack of pseudo cross-sectional image. Not the internal of cross section is authentic, but the edge or contour is valid. Copyright UNION Agency - Science Press.
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Non-linear image registration using perspective invariant and thin-plate spine
(2004-12-01)
Putjarupong, P.
;
Pintavirooj, C.
;
Nantivatana, P.
;
Withayachumnankul, W.
;
Sangworasil, M.
We introduce a non-iterative geometric-based method to register an image using a novel set of geometric landmarks residing on an extracted 2D contours from the image. These landmarks are intrinsic and computed from the differential geometry of the curve. We exploit the invariant properties of maximum-curvature points that are local and robust under the affine and some perspective transformation. Geometric invariant exploits five-point coplanar invariant constructed from 5 consecutive landmarks. This invariant is preserved not only in affine map but weak perspective map as well. The alignment is achieved by establishing correspondences between the landmarks after a conformal sorting based on derived absolute invariant and undoing non-linear transformation which is a Thin-Plate Spline (TPS). The experiments have shown that the purposed methods are robust and promising even in the presence of noise. © 2004IEEE.
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Ultrasonic diffraction tomography: The experimental result
(2005-12-01)
Pintavirooj, C.
;
Jaruwongrungsee, K.
;
Withayachumnankul, W.
;
Hamamoto, K.
;
Daochai, S.
Diffraction tomography is a technique for imaging with acoustic fields. It takes advantage of the linearization process of the non-linear wave equation describing wave propagation in heterogeneous media. When the scattering effect is weak, one can invoke the Born or Rytov approximation and thus derive the generalized Fourier Slice Theorem to reconstruct the cross-section of the insonified object. Although diffraction tomography is a promising technology for medical application as it provides a quantitative ultrasonic image, its realization toward medical use is still far-to-go, this may be due to the complexity of the hardware involved. In this research we investigate a potential use of diffraction tomography for medical application by using a delicate-designed ultrasonic computerized tomographic system. The result of experiment investigation of diffraction tomography is very promising. Copyright UNION Agency - Science Press.
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Acceleration of genetic algorithm with parallel processing with application in medical image registration
(2005-12-01)
Laksanapanai, B.
;
Withayachumnankul, W.
;
Pintavirooj, C.
;
Tosranon, P.
Generally, image registration using genetic algorithm is a time-consuming process since the algorithm needs to evaluate the objective function several hundred times depending on the vastness of search space. The situation appears worse if the registration is intensity-based due to the interpolation loops prior to each objective function. However, with the availability of parallel processing method, one can accelerate the application of genetic algorithm for iterative-based image registration process of up 80 % for multi-modality alignment. Copyright UNION Agency - Science Press.
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Hardware-accelerated objective function evaluation for medical image registration
(2004-12-01)
Withayachumnankul, W.
;
Laksanapanai, B.
;
Pintavirooj, C.
Generally, image registration using genetic algorithm is a time-consuming process since the algorithm needs to evaluate the objective fonction several hundred times depending on the vastness of search space. The situation appears worse if the registration is intensity-based due to the interpolation loops prior to each objective function. However, with the availability of modern graphic processing unit (GPU) one can take an advantage from interpolating division normally used to interpolate the texels for 2D-texture mapping. Issued via OpenGL API, the image interpolation requires half time less than it ever does without losing of accuracy. © 2004IEEE.
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Ultrasonic refractive index and sound velocity tomography
(2004-12-01)
Pintavirooj, C.
;
Jaruwongrungsee, K.
;
Withayachumnankul, W.
;
Hamamoto, K.
;
Taertulakarn, S.
Ultrasonic computed tomography (UCT) is one of the methods capable of tissue characterization. It is expected to provide not only a quantitative image but also diagnostic information. As in X-ray CT, UCT requires a projection data to reconstruct a cross-sectional image. The projection data of Ultrasonic Tomography is based on measurement the time delay, which is time difference between ultrasound traverse with and without object. In this paper, we investigate two different types of quantitative UCT image, refractive-index and sound-velocity image. We purpose the new method of measurement the time delay by converting the received ultrasonic pulse to frequency domain and measuring the phase shift of the center frequency of the broadband pulse. The method seems more robust to noise. Two image reconstruction techniques are used for comparison purpose including traditional filtered back-projection and simultaneous algebraic reconstruction technique (SART). © 2004 IEEE.
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3D modeling from using spiral cone-beam trajectory
(2005-01-01)
Narkbuakaew, W.
;
Withayachumnankul, W.
;
Pintavirooj, C.
;
Sangworasil, M.
Tomographic imaging is a technique for exploration of a cross-section of an inspected object without destruction. Normally, the input data, known as the projections, are gathered by repeatedly radiating coherent waveform through the object in a number of viewpoints, and receiving by an array of corresponding detector in the opposite position. In this research, as a replacement of radiographs, the series of photographs taken around the opaque object under the ambient light is completely served as the projections. The process is called photographic tomograph. In this paper, we purpose the 3D shape extraction based on using photographic tomography with spiral cone-beam trajectory. We have demonstrated that the purposed technique can rectify the problem of perspective occlusion that occurs when using cone-beam trajectory.
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Ultrasonic diffraction tomography by pulse-plane wave: Experimental result by frequency synthesis method
(2005-01-01)
Tangtisanon, G.
;
Jaruwongrunsee, K.
;
Withayachumnankul, W.
;
Hamamoto, K.
;
Pintavirooj, C.
Diffraction tomography is a technique for imaging with acoustic fields in which parameter, such as reflective index, sound velocity, etc., can be mapped from scatter wave resulting from insonifying the object with a plane wave at a single temporal frequency. By solving the direct scattering problem, the scattered field can be presented in term of scattering parameters. Different inversion techniques can be applied to take advantage of the linearization process of the non-linear wave equation describing wave propagation in heterogeneous media under a limited class of scattering. Specifically, when the scattering effect is weak, one can invoke the Born or Rytov approximation and thus derive the generalized Fourier Slice Theorem to reconstruct the cross-section of the insonified object. Although diffraction tomography is a promising technology for medical application as it provides a quantitative ultrasonic image, its realization toward medical use is still far-to-go, and this may be due to the complexity of the hardware involved. In this research we investigate a potential use of diffraction tomography for medical application by using a delicate-designed ultrasonic computerized tomographic system. The contribution of the paper is that we have purposed to Frequency Synthesis Method (FSM) that uses 3 frequency components of the Fourier transform of scattered filed, i.e. the center frequency and the -3 dB from center frequency of both side, to fill Fourier space for the generalized Fourier slice theory. The reconstructed ultrasonic image from such theory provides a very promising result. © 2005 IEEE.
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Shape matching using set of curve geometric invariant point
(2005-12-01)
Pintavirooj, C.
;
Nantivatana, P.
;
Putjarupong, P.
;
Withayachumnankul, W.
;
Sangworasil, M.
We introduce a non-iterative geometric-based method for shape matching using a novel set of geometric landmarks residing on a 2D contours. These landmarks are intrinsic and are computed from the differential geometry of the curve. We exploit the invariant properties of geometric landmarks that are local and preserved under the affine and some perspective transformation. Geometric invariant exploits coplanar five-point invariant and ration of area constructed from a sequence of consecutive landmarks. These invariants are preserved not only in affine map but weak perspective map as well. To reduce the sensitivity of the landmarks to noise, we use a B-Spline surface representation that smoothes out the curve prior to the computation of the landmarks. The matching is achieved by establishing correspondences between the landmarks after a conformal sorting based on derived absolute invariant and registering the contours. The experiments have shown that the purposed methods are robust and promising even in the presence of noise. Copyright UNION Agency - Science Press.
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3D shape extraction of large object using photographic tomography
(2004-12-01)
Reruang, S.
;
Withayachumnankul, W.
;
Pintavirooj, C.
;
Airphaiboon, S.
;
Lertpasert, P.
Tomographie imaging is a technique for exploration of a. cross-section of an inspected object without destruction. Normally, the input data, known as the projections, are gathered by repeatedly radiating coherent waveform through the object in a number of viewpoints, and receiving by an array of corresponding detector in the opposite position. In this research, as a replacement of radiographs, the series of photographs taken around the opaque object under the ambient light is completely served as the projections. From the process of tomography, the outcome is the stack of pseudo cross-sectional image. Not the internal of cross section is authentic, but the edge or contour is valid. Here, its application is focused on the 3D modelling of the large object with the true colour rendering. Nevertheless, the process has a problem to extract the highly concave-shape object due to the blind of camera by the occluded patches. © 2004IEEE.

Pintavirooj, Chuchart

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