2.3. Boundary detection
To obtain the feature data of the prediction model, the boundary
data of a pig’s body image is required. Because the pixel
coordinate is a location in an image, it cannot be used directly
for numerical computation; therefore, in practice, it is necessary
to convert the pixel locations to 2D vectors (i.e., in x, y coordinates)
in the Cartesian coordinate system. Then, the vector-valued functions
can be computed using mathematical techniques. In our
work, the pixel locations of the image’s boundary are manually
identified. A graphical user interface (GUI) program is developed