Video Analysis of Runup 
Wave runup data were obtained using an Imaging Technology Incorporated 
video image processing system (model ITI-151) interfaced to a Sun host 
computer. By using the GCP’s as control and knowing the profile coordinates, 
time series of wave runup were generated from the video. Runup was 
measured along one beach profile line located near the primary cross-shore 
array, at longshore coordinate 986 m. Beach profiles were surveyed once per 
day near low tide. Camera geometries were computed for each runup 
collection. 
Onshore Distance Offshore 
Runup time series was 
performed by the Coastal 
Imaging Laboratory at the 
Oregon State University, 
Corvallis, OR. The runup 
analysis technique is based on the 
"timestack" method described by 
Aagaard and Holm (1989).' A 
timestack is created by digitizing 
every fifth video frame (6 Hz) 
and recording the pixel 
intensities in the image that 
correspond to the profile line 
location. These pixel values are 
then “stacked” in a matrix and 
saved on disk. This results in a 
matrix of pixel intensities with 
one axis being the pixel position, 
directly related to the distance 
across the structure, and the 
other axis being time. Ina 
typical timestack (Figure B25) 
the runup is clearly visible as a 
sharp change in pixel intensity, 
between the darker beach on the 
left, and the whiter foam of the 
runup on the right. 
The cross-shore position of 
the runup is determined from the Figure B25. Example segment of a runup 
runup edge position in the timestack 
timestack image. Image 
; Aagaard, T., and Holm, J. (1989). “Digitization of wave run-up using video records,” 
Journal of Coastal Research 5, 547-551. 
Appendix B Video Data 
B21 
