Sample list of features used in our study
| The values in parenthesis refer to an arbitrary code number with which the feature is identified in the computer program. |
| • Total optical density (feature number 001) |
| • Nuclear area (feature number 002) |
| • Variance of optical density (OD) values (feature number 006) |
| • Pixel OD histogram (0.2–0.3 bin) (feature number 010) |
| • Run length feature (OD, 0.0–0.3, 1–2 pixels) (feature number 267) |
| • Run length feature (OD 0.3–0.6, 3–4 pixels) (feature number 274) |
| • Percentage of long runs (feature number 304) |
| • Grey level non-uniformity (feature number 305) |
| • Run length non-uniformity (feature number 306) |
| • Percentage of pixels occurring in a run (feature number 307) |
| • Mean OD value (feature number 317) |
| • OD value 20% above mean OD (feature number 318) |
| • Total number of very dark pixels (feature number 319) |
| • Total number of light pixels (feature number 320) |