  In the field of volumetric data processing and analysis, extracting
mid-surfaces from thinly bounded compartments is crucial for tasks such as
surface area estimation and accurate modeling of biological structures, yet it
has lacked a standardized approach. To bridge this gap, we introduce
MidSurfer--a novel parameter-free method for extracting mid-surfaces from
segmented volumetric data. Our method produces smooth, uniformly triangulated
meshes that accurately capture the structural features of interest. The process
begins with the Ridge Field Transformation step that transforms the segmented
input data, followed by the Mid-Polyline Extraction Algorithm that works on
individual volume slices. Based on the connectivity of components, this step
can result in either single or multiple polyline segments that represent the
structural features. These segments form a coherent series across the volume,
creating a backbone of regularly distributed points on each slice that
represents the mid-surface. Subsequently, we employ a Polyline Zipper Algorithm
for triangulation that connects these polyline segments across neighboring
slices, yielding a detailed triangulated mid-surface mesh. Our findings
demonstrate that this method surpasses previous techniques in versatility,
simplicity of use, and accuracy. Our approach is now publicly available as a
plugin for ParaView, a widely-used multi-platform tool for data analysis and
visualization, and can be found at https://github.com/kaust-vislab/MidSurfer .
