Update data sources table to match CSV files and make licencing agreement clearer.

README.md

@@ -134,20 +134,26 @@ Per-image source information is in `training_data_sources.csv` and
 `test_data_sources.csv` (columns: `new_name`, `Source`, `Link`, `Data Reference`,
 `Paper Reference`).
 
-Images were contributed by several groups and are published with their agreement.
+Images were sourced from internal acquisitions, collaborating research groups,
+and previously published datasets. Data taken from published sources was already
+available under CC-BY-4.0; contributing authors of unpublished data have confirmed
+their agreement to release under CC-BY-4.0.
+
 Filenames are numeric; sample identities are not disclosed for unpublished
 internal data. Where images originate from published datasets they carry full
 citations in the source tables.
 
-| Source | Images |
-| --- | --- |
-| University of Leeds AFM Facility | 1452 |
-| George Heath — Scheuring Lab — New York | 511 |
-| Pyne Lab — University of Sheffield | 115 |
-| Nanobiomaterials Group — Paderborn University | 62 |
-| Varun Gupta — Heath Lab, University of Leeds | 10 |
-| Abimbola Olulana — Hobbs Lab, University of Sheffield | 8 |
-| BioMed AFM Summer School — Sheffield | 7 |
+| Contributor | Train | Test | Total |
+|---|---|---|---|
+| University of Leeds AFM Facility | 1106 | 68 | 1174 |
+| George Heath — Scheuring Lab — New York | 465 | 46 | 511 |
+| Varun Gupta — Heath Lab, University of Leeds | 210 | 21 | 231 |
+| Pyne Lab — University of Sheffield | 114 | 1 | 115 |
+| Nanobiomaterials Group — Paderborn University | 58 | 4 | 62 |
+| Daniel E. Rollins — Heath Lab, University of Leeds | 48 | 9 | 57 |
+| Abimbola Olulana — Hobbs Lab, University of Sheffield | 0 | 8 | 8 |
+| BioMed AFM Summer School — Sheffield | 0 | 7 | 7 |
+| **Total** | **2001** | **164** | **2165** |
 
 ### Published source datasets — please cite when using these images