3D-shape retrieval using curves and HMM

International audienceIn this paper, we propose a new approach for 3D-shape matching. This approach encloses an off-line step and an on-line step. In the off-line one, an alphabet, of which any shape can be composed, is constructed. First, 3D-objects are subdivided into a set of 3D-parts. The subdivision consists to extract from each object a set of feature points with associated curves. Then the whole set of 3D-parts is clustered into different classes from a semantic point of view. After that, each class is modeled by a Hidden Markov Model (HMM). The HMM, which represents a character in the alphabet, is trained using the set of curves corresponding to the class parts. Hence, any 3D-object can be represented by a set of characters. The on-line step consists to compare the set of characters representing the 3D-object query and that of each object in the given dataset. The experimental results obtained on the TOSCA dataset show that the system efficiently performs in retrieving similar 3D-models

The values of optimal collimator angles for each of sectional arcs for abdominal case.

<p>The values of optimal collimator angles for each of sectional arcs for abdominal case.</p

Average dose-volumetric parameters of abdominal cases.

<p>Average dose-volumetric parameters of abdominal cases.</p

Mean total MUs for abdominal, head and neck, and chest cases.

<p>Mean total MUs for abdominal, head and neck, and chest cases.</p

Percentage of dose difference less than 3% between Plan_{_PLA} and Plan_{_VB}, and Plan_{_Bolus} and Plan_{_VB} for 200 cc, 300 cc, 400 cc, 500 cc and 650 cc attachments using 3- and 5-mm-thick bolus

<p>Percentage of dose difference less than 3% between Plan_{_PLA} and Plan_{_VB}, and Plan_{_Bolus} and Plan_{_VB} for 200 cc, 300 cc, 400 cc, 500 cc and 650 cc attachments using 3- and 5-mm-thick bolus</p

An example of area size difference between the integrated multi-leaf collimator (MLC) aperture and collimator settings with 5 mm-margins to the integrated MLC aperture with respect to collimator angles in the case of an angular section of 40°.

<p>Collimator angles were rotated at intervals of 2° ranging from 0° to 90°. Red (square) points for each sectional arc were minimum area size differences.</p

Average dose-volumetric parameters of head and neck cases.

<p>Average dose-volumetric parameters of head and neck cases.</p

Patient characteristics.

<p>Patient characteristics.</p

The percentage difference between the calculated and measured doses for Plan__PLA and Plan__bolus with a 200 cc attachment at both sides of the nipple (Np) and breast surface (Bs).

<p>The percentage difference between the calculated and measured doses for Plan__PLA and Plan__bolus with a 200 cc attachment at both sides of the nipple (Np) and breast surface (Bs).</p

Physical properties of the clear-PLA and 3D printer settings.

<p>Physical properties of the clear-PLA and 3D printer settings.</p