NASA Spinoff

Hierarchical Segmentation Enhances Diagnostic Imaging

Developed by Dr. James Tilton, a computer engineer with Goddard Space Flight Center’s Computational and Information Sciences and Technology Office, Hierarchical Segmentation (HSEG) software allows for advanced image analysis. The software organizes an image’s pixels into regions based on their spectral similarity, so rather than focusing on individual pixels, HSEG focuses on image regions—and how they change from a coarse-to-fine perspective. These regions (segmentations) are at several levels of detail (hierarchies) in which the coarser segmentations can be produced from the finer-resolution segmentations by selective merging of regions. In addition, the segmentation hierarchies provide analysis clues through the behavior of the image region characteristics over several levels of segmentation detail. Thus, by enabling region-based analysis, the segmentation hierarchies organize image data in a manner that makes an image’s information content more accessible.

Within NASA, HSEG was used to identify and extract magnetospheric radio-echo and natural plasma-wave signals captured by the Radio Plasma Imager aboard the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft, which was launched in March 2000, and after completing its 2-year primary mission, was lost in space after a full 5.8 years of exploration.

To advance the usability of the HSEG, Tilton also developed Recursive Hierarchical Segmenting (RHSEG) Pre-processing Software, which significantly improves the extraction of patterns from complex data sets. Optimized for speed and accuracy, the patent-pending algorithm that fuels the software provides the user with precise control for selecting the desired level of detail from the hierarchy of results. The software allows the user to group non-spatially adjacent regions for flexibility with a wide range of image and data types, providing accurate graphic representation of imagery data with minimal distortion and a fine resolution of detail.

Although originally developed for NASA’s remotesensing applications, HSEG has proven its value in other realms as well. Also originally designed for remote Earth sensing, the RHSEG Pre-processing Software is broadly applicable for a variety of uses, from medical imaging to data mining, and it is now capable of three-dimensional (3-D) data analysis, a capability NASA is in the process of patenting.

Partnership

Bartron Medical Imaging LLC (BMI), of New Haven, Connecticut, gained a nonexclusive license from Goddard Space Flight Center to use the RHSEG software in medical imaging.

In order to manage the image data, BMI also licensed two pattern-matching software programs from NASA’s Jet Propulsion Laboratory that were used in image analysis and three data-mining and edge-detection programs from Kennedy Space Center. The Kennedy imaging technologies are currently in use at NASA to identify and track foreign object debris during space shuttle liftoff, and in the Cable and Line Inspection Mechanism used to test the shuttle’s emergency escape system.

In addition, BMI made NASA history by being the first company to partner with the Space Agency through a Cooperative Research and Development Agreement (CRADA). This agreement, for development of the 3-D version of RHSEG, grants (in advance) a partially exclusive license for the resulting technology patents within BMI’s fields of use (i.e., the diagnosis and treatment of breast cancer, cervical cancer, brain cancer, heart disease, osteoporosis, and periodontal diseases).