First Defocus Particle Tracking Challenge: Chip-in-the-Box and Multi-Flavor Datasets
(release of test cases in November 2025, submission of results by May 2026)

We are excited to announce the First Defocus Particle Tracking (DPT) Challenge for a benchmark initiative to assess and compare 3D3C particle tracking methodologies based on defocusing.

The challenge is open to all users and developers of single-camera particle-tracking techniques where the depth coordinate is inferred from the degree of defocus in particle images. This includes – but is not limited to – astigmatism, multi-aperture systems (e.g., 3-pinholes), shadowgraphy (depth from defocus), and related approaches.

You can join the Challenge on both Test Cases (ChiB and MFD) or just on one of them.

The Test Cases:

  • Chip-in-the-Box (ChiB): A physical microfluidic chip will be shipped to each participant. You may apply your preferred defocusing technique and parameter settings to measure the flow inside selected sections of the device. Details on experimental parameters (flow rate, field of view, expected format of results, etc.) will be provided upon registration. The ChiB is ready to be sent!
Christian Cierpka
Chip DesignChristian Cierpka
  • Multi-Flavor Datasets (MFD): Three synthetic datasets are provided in several “flavors” of defocusing image formation, including astigmatism, pinholes, and shadowgraphy. The datasets are ready to be downloaded!
Multi-Flavor-DatasetMassimiliano Rossi

More information on the datasets is available to the DPT Challenge paper presented at the 16th International Symposium on Particle Image Velocimetry – ISPIV 2025, June 26–28, 2025, Tokyo, Japan .

 

Key dates:

- May 15th 2026: Final deadline for the submission of results. No deadline to join the Challenge.

- June 29th - July 2nd 2026: Presentation of the Challenge results at the Lisbon Symposium

   

How to participate:

- Register to the challenge here. (email, affiliation, and which test cases you intend to join) 

- After registration, you will receive instructions on how to receive the ChiB, download the MFD, and submit your results in the required format.

 

For technical assistance, please contact: massimiliano.rossi13@unibo.it or sebastian.sachs@tu-ilmenau.de