Computational Imaging Metrology Charts
3D objects for benchmarking computational imaging systems such as CT and MRI — designed to measure frequency response and volume linearity end-to-end.
Table of Contents
Overview
The Computational Imaging Metrology Charts are 3D objects designed to benchmark computational imaging systems end-to-end. When scanned and reconstructed, the objects allow the frequency response of the imaging system to be measured. The design produces a reconstructed image resembling a Siemens Star, enabling quantitative performance measurements.
Two charts are provided, each targeting a different measurement:
| Chart | Purpose | File format |
|---|---|---|
| CI Density Chart | Measures volume linearity vs position | .stl, .stp |
| CI Frequency Chart | Measures spatial frequency response | .stl, .stp |
CI Volume Chart
The geometry of this chart is designed so that a reconstructed slice will have every point’s relative thickness is proportional to its distance from the centre:
- The chart height equals its radius, so finding the radius gives the thickness
- The centre has 0% depth for odd slices and 100% depth for even slices
- The edge is 100% depth for odd slices and 0% depth for even slices
The chart must be aligned parallel to the slicing plane for accurate measurements.
Download:
CI Frequency Chart
The geometry of this chart requires no precise alignment. After slices are computed, the slice with the largest circle diameter is selected for measurement — this is the reference slice used to characterise the system’s spatial frequency response.
Download:
File Formats
| Format | Description | Use case |
|---|---|---|
.stl | Stereolithography mesh | 3D printing, simulation |
.stp | STEP CAD format | CAD software, manufacturing |
License
MIT License — see LICENSE on GitHub.