Ohio State researchers explore photogrammetry, the future of solving cold cases

Zoe Botley
Tue, 24 Oct 2023 00:02:29 +0000
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Ohio State researchers are working to make identifying skeletal remains easier through photogrammetry Credit: Courtesy of Senior Graphic Researcher Jeremy Patterson

Identifying skeletal remains just got a bit easier for the Ohio Bureau of Criminal Investigation thanks to Ohio State researchers.

Dean Hensley, an instructional design specialist, is working to provide a new way of reconstructing faces through photorealistic digital images alongside senior graphics researcher Jeremy Patterson. The two developed the program to assist criminal intelligence analysts who can reconstruct human skulls just by sending a picture from their phones.?

One of the analysts, Samantha Molnar, said she wanted to partner with others at the university to work on the reconstruction project. Upon meeting Hensley, they began to develop a process known as “photogrammetry,” where they could make scans with an iPhone application rather than specialized hospital equipment.

Molnar said by capturing pictures via her iPhone, Hensley and Patterson considerably reduced the time and funding it took to develop skull reconstruction. Molnar said she no longer had to pay the hospital a visit for a CT scan, as now with photogrammetry, she could upload the skulls to be 3D printed by the Digital Union, which would then be rendered via digital 3D modeling.

“After we did that, the prints were coming out better. Then I got to meet Jeremy [Patterson], and he helped improve the process even more,” Molnar said. “It’s just been an awesome partnership that’s allowed this to grow, become faster, and more accurate.”?

They rolled out the program for official use through Ohio State in the last month, beginning work on their first case with Stark County officials using this new technology.

Now, with Hensley and Patterson’s assistance, the officials were able to produce a more straightforward process than traditional clinical imaging, which used volumetric reconstruction of CT scanning and MRI visuals with extra interior detailing. Their new way creates more simplified scans with only the needed data regarding the outside surface, creating lower chances of failing during the 3D printing process.?

Data prior to the switch took up to 10 days to print one scan. The new surface scans can be completed in only a few days, according to Molnar.?

As a former video game developer, Patterson said he never expected to use previous work experience to identify remains. Through a program called “Mesh,” a software used exclusively for video games, he is able to take the clay structure via photogrammetry previously done by Molnar and use the tool to identify different facial characteristics.

“From there, just like you would build an avatar in a video game, you have a menu of options where you can go in and choose eye color, hair length and skin tone. All of these things are variations that can be helpful,” Patterson said.

If DNA analysis cannot give proper identification, Molnar said she then starts the facial reconstruction clay process. Once completed, the photogrammetry scan sent from Molnar’s phone is processed into the software, providing variations on what the victim might have looked like.?

As genealogy advances over time, the software can feed these new characteristics, providing higher accuracy of victims of cold cases becoming identified.

Though the process is in its early stages, Molnar said she found that specific characteristics they struggled with were weight and age. They rely on estimations from anthropologists for age, though it’s more difficult for weight.?

“I don’t know their eye color, hair color, facial hair, and most times I don’t even know their hairstyle because they’re too far decomposed by the time I get them, they’re all guesses,” Molnar said. “When it comes to weight, the only tool I have is clothing size that people are found in. But a lot of the time when the skeletal remains are found, there aren’t clothing [due to] maybe animal activity taking place.”?

Molnar said she hopes to use this information for cold cases to tweak old reconstructions to be more accurate. Under the old system, Patterson and Hensley assisted with 10 to 12 cases. As DNA analysis advances, Patterson and Hensley said they hope they will be able to help Molnar more in the future.?

“I think one of the reasons I’ve really enjoyed this process is because we were able to give back and to use technology in a way that’s not just for entertainment, but using it to help others,” Hensley said. “We’ve been able to provide the services the same so that we can enhance her [Molnar’s] work and make it easier to find these identities of people who their families don’t know what happened to them.”