Apple CT Data: Ground truth reconstructions - 2 of 6

Summary
This submission is a supplementary material to the article [Coban 2020b]. As part of the manuscript, we release three simulated parallel-beam tomographic datasets of 94 apples with internal defects, the ground truth reconstructions and two defect label files. 

Description
This Zenodo upload contains the ground truth reconstructed slices for each apple. In total, there are 72192 reconstructed slices, which have been divided into 6 separate submissions:

ground_truths_1.zip (1 of 6): 10.5281/zenodo.4550729 

ground_truths_2.zip (2 of 6): 10.5281/zenodo.4575904 (this upload)

ground_truths_3.zip (3 of 6): 10.5281/zenodo.4576078 

ground_truths_4.zip (4 of 6): 10.5281/zenodo.4576122 

ground_truths_5.zip (5 of 6): 10.5281/zenodo.4576202 

ground_truths_6.zip (6 of 6): 10.5281/zenodo.4576260 

The simulated parallel-beam datasets and defect label files are also available through this project, via a separate Zenodo upload: 10.5281/zenodo.4212301.

Apparatus
The dataset is acquired using the custom-built and highly flexible CT scanner, FleX-ray Laboratory, developed by TESCAN-XRE, located at CWI in Amsterdam. This apparatus consists of a cone-beam microfocus X-ray point source that projects polychromatic X-rays onto a 1944-by-1536 pixels, 14-bit, flat detector panel. Full details can be found in [Coban 2020a].

Ground Truth Generation

We reconstructed the raw tomographic data, which was captured at sample resolution of 54.2µm over a 360 degrees in circular and continuous motion in a cone-beam setup. A total of 1200 projections were collected, which were distributed evenly over the full circle. The raw tomographic data is available upon request.

The ground truth reconstructed slices were generated based on Conjugate Gradient Least Squares (CGLS) reconstruction of each apple. The voxel grid in the reconstruction was 972px x 972px x 768px. The resolution in the ground truth reconstructions remained unchanged.

All ground truth reconstructed slices are in .tif format. Each file is named "appleNo_sliceNo.tif".

List of Contents
The contents of the submission is given below.

ground_truths_2: This folder contains reconstructed slices of 15 apples

Additional Links
These datasets are produced by the Computational Imaging group at Centrum Wiskunde & Informatica (CI-CWI). For any relevant Python/MATLAB scripts for the FleX-ray datasets, we refer the reader to our group's GitHub page.

Contact Details
For more information or guidance in using these dataset, please get in touch with 

s.b.coban [at] cwi.nl

vladyslav.andriiashen [at] cwi.nl

poulami.ganguly [at] cwi.nl

Acknowledgments
We acknowledge GREEFA for supplying the apples and further discussions.