A free 3d medical image viewer (windows/linux/macosx) - DICOM

This is a discussion on A free 3d medical image viewer (windows/linux/macosx) - DICOM ; stefanbanev@yahoo.com wrote: > lzyhm wrote: > > stefanbanev@yahoo.com wrote: > > > > > > One of mentioned feature is "Surface Generation". The impulse > > > opacity transfer function (step like) should provide iso-surface so, > > > why ...

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Thread: A free 3d medical image viewer (windows/linux/macosx)

  1. Re: A free 3d medical image viewer (windows/linux/macosx)


    stefanbanev@yahoo.com wrote:
    > lzyhm wrote:
    > > stefanbanev@yahoo.com wrote:
    > > >
    > > > One of mentioned feature is "Surface Generation". The impulse
    > > > opacity transfer function (step like) should provide iso-surface so,
    > > > why this very particular case of volume rendering is distinguished in
    > > > separate nomination?
    > > >

    > > If you define left eye ROI slice by slice, tviewer can generate the
    > > surface by ROIs even the slices have different spacing.

    >
    > The original data provides just set of interpolation grids thus, what
    > so special about a non-regular spacing. The iso-surface of volume is
    > still perfectly defined from point of view of interpolator (tri-linear
    > or higher) so, impulse transfer function must show the correspondent
    > iso-surface of scalar field seeing by interpolator. The quality of
    > iso-surface obtained through step-TF is heavily depends on
    > super-sampling level and order of interpolation (tri-linear or higher).
    > To get comparatively accurate mesh-based iso-surface you will need at
    > least 8 polygons per voxel what actually excessively far more expensive
    > than super-sampling ray-casting approach. Definitely the polygonal
    > substitution is a viable option for many applications where a draft
    > approximation is acceptable.


    The generation of iso-surface based on marhing-cubs commonly. the
    marhing-cubs'input is auto-segmentation result by impulse transfer
    function. The speed is slow, the more importance is the
    auto-segmentation result has many other uncorrect infomation, many
    arithmetic must be distribute to remove these uncorrect segmentation.
    and the mesh-based iso-surface is diffcult for advance computation such
    statistic or DVH evaluation etc. The define ROIs by hand still is used
    in many situation.


  2. Re: A free 3d medical image viewer (windows/linux/macosx)


    lzyhm wrote:
    > stefanbanev@yahoo.com wrote:
    > > lzyhm wrote:
    > > > stefanbanev@yahoo.com wrote:
    > > > >
    > > > > One of mentioned feature is "Surface Generation". The impulse
    > > > > opacity transfer function (step like) should provide iso-surface so,
    > > > > why this very particular case of volume rendering is distinguished in
    > > > > separate nomination?
    > > > >
    > > > If you define left eye ROI slice by slice, tviewer can generate the
    > > > surface by ROIs even the slices have different spacing.

    > >
    > > The original data provides just set of interpolation grids thus, what
    > > so special about a non-regular spacing. The iso-surface of volume is
    > > still perfectly defined from point of view of interpolator (tri-linear
    > > or higher) so, impulse transfer function must show the correspondent
    > > iso-surface of scalar field seeing by interpolator. The quality of
    > > iso-surface obtained through step-TF is heavily depends on
    > > super-sampling level and order of interpolation (tri-linear or higher).
    > > To get comparatively accurate mesh-based iso-surface you will need at
    > > least 8 polygons per voxel what actually excessively far more expensive
    > > than super-sampling ray-casting approach. Definitely the polygonal
    > > substitution is a viable option for many applications where a draft
    > > approximation is acceptable.

    >
    > The generation of iso-surface based on marhing-cubs commonly. the
    > marhing-cubs'input is auto-segmentation result by impulse transfer
    > function. The speed is slow, the more importance is the
    > auto-segmentation result has many other uncorrect infomation, many
    > arithmetic must be distribute to remove these uncorrect segmentation.
    > and the mesh-based iso-surface is diffcult for advance computation such
    > statistic or DVH evaluation etc. The define ROIs by hand still is used
    > in many situation.


    Marching cube may provide very rough iso-surface representation,
    however for many applications it may sufficient.


    Thanks,
    --sb


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