KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Access type: UnknownAuthor: search.filters.author.Narkbuakaew, W.

Search Results

Now showing 1 - 3 of 3
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    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.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    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.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Multiresolution image alignment based on discrete wavelet transform
    (2005-01-01)
    Lohakan, M.
    ;
    Nantivatana, P.
    ;
    Narkbuakaew, W.
    ;
    Pintaviroj, C.
    ;
    Sangworasil, M.
    We introduce a multi-resolution image registration based on using discrete wavelet transform. We first extract contour from both images that we want to align. The extracted contours are then fitted with B-spline curve representation to synthesize the new contours with equal number of point. The area parameter is used in the B-spline fitting to make the new generated curve immune to affine transformation. Before representing the B-spline contour with discrete wavelet transform, the problem of starting point of the contour needs to be handle. This can be done by computing the maximum curvature. The maximum curvature is selected as the starting point. Once the starting points on the contour have been established, the discrete wavelet transform is then recursively represented the contours until only a few points are remained. Due to the affine-invariant properties of discrete wavelet transform, these points can be used as landmark points for registering the transformed contour with the original contour. The experiments have shown that the purposed methods are robust and promising even in the presence of noise.