CHAPTER 16: CASE STUDY 1: GAME-CONTROLLING GESTURES comparing vertical movement along the running cycle. Fortunately, precise values were not necessary from the point of view of computer vision design, which in the end mainly relied on the video sequences produced during the description process. The detailed analysis of the movements was based mainly on image sequences of the videos, which are typically only 5 to 25 PAL video frames (200 to 1,000 milli- seconds) in length (such as one running or jump cycle). The sequences are usually easier to analyze with all the frames visible side by side, compared to the frame-by- frame manipulation of video editors or annotation tools. Another benefit of having the movement cycle visible in its entirety was that the frequency of steps, differ- ent phases in the movement cycle, and the phrase durations were relatively easy to measure. Additionally, the sequences could be used more easily than the Laban notation staffs to inform the game character design later on, as it did not require learning any particular notification system. Results from the Study