Table 1 Types of measurements made
From: High-throughput mammographic-density measurement: a tool for risk prediction of breast cancer
Area measurements | |
|---|---|
Count | Numbers of particles |
TotalArea | Area of selection in square pixels |
AverageSize | Average size of each particle (TotalArea divided by count) |
Area Fraction | The percentage of pixels in the image or selection that have been thresholded |
Intensity measurements | |
Mean gray value | Average gray value within the selection. This is the sum of the gray values of all the pixels in the selection divided by the number of pixels |
Modal gray value | Most frequently occurring gray value within the selection. Corresponds to the highest peak in the histogram |
Median | The median value of the pixels in the image or selection |
Shape descriptors | |
Circularity | 4π (area/perimeter2). A value of 1.0 indicates a perfect circle. As the value approaches 0.0, it indicates an increasingly elongated polygon. Values may not be valid for very small particles |
Solidity | Area/convex area |
Others | |
Integrated density | The sum of the values of the pixels in the image or selection. This is equivalent to the product of Area and Mean Gray Value |
Skewness | The third-order moment about the mean |
Kurtosis | The fourth-order moment about the mean |
Perimeter | The length of the outside boundary of the selection |
Fit ellipse | Fit an ellipse to the selection. Uses the headings Major, Minor, and Angle. Major and Minor are the primary and secondary axis of the best-fitting ellipse. Angle is the angle between the primary axis and a line parallel to the × axis of the image |