Polynomial Texture Mapping for Footwear and Tire Impressions Technology Transition Workshop

Polynomial Texture Mapping for Footwear and Tire Impressions Technology Transition Workshop

July 12-13, 2007
National Forensic Science Technology Center
Largo, Florida

Workshop Leader: John Yoshida
Workshop Instructors: James Hamiel
Workshop Overview

The purpose of this technology transfer workshop is to provide the student with an introduction to Polynomial Texture Mapping (PTM).The PTM technology is applied to footwear and tire track impression evidence. The class will include lecture, demonstration, and laboratory exercises for the student to learn about the use of PTM technology to footwear and tire track impression comparisons.

The theory and application of Polynomial Texture Mapping will be discussed and practical applications will be demonstrated.The various PTM components will be discussed including the building of a PTM dome, camera/lens selection and PTM files. Various samples will be used to demonstrate this technique including casts, impressions in blood and other matrices. The student will gain an appreciation of the principles underlying the software as well as the use of various functions available.

The student will build their own PTM files and utilize the PTM software to practice the different modes used in analyzing impressions with the PTM software. The student will be given the tools to build their own PTM files.
Learning Outcomes

At the completion of the Polynomial Texture Mapping for Footwear and Tire Impressions Technology Transfer Workshop, the participant will acquire the knowledge to:
  • Understand the basic theory and applications of Polynomial Texture Mapping
  • Gain the knowledge to select the proper digital camera/lens for shoe/tire impression documentation
  • Understand the minimum requirements for building a PTM dome
  • Understand the PTM application as applied to shoe and tire track impression evidence
  • Understand the step-by-step process used in building a PTM file from a collection of digital images
  • Be able to navigate the PTM software to bring out different detail in a captured impression
  • Understand the different PTM modes for image enhancement
  • Evaluate the PTM method vs. “traditional” impression comparisons
  • Summarize the PTM method for impression comparisons

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