time recognition of video clock for live event alert system
In this paper, we propose an algorithm to recognize the time of video clock in broadcast soccer videos. A naive OCR approach to the problem will be confounded by standard image segmentation issues such as merged digits and low-resolution. In contrast, our methods achieve robustness by exploiting the domain knowledge governing clock digit transitions. The time periodicity information enables the reliable recognition of overlaid digit video clock and also facilitates self-consistency checks. A robust time recognition algorithm was presented in our previous papers. However, that algorithm requires the precise ROI ( Region Of Interest ) as its input. Besides inheriting the existing techniques this paper proposes two new ones to overcome the impreciseness of ROIs. The first one is the extended-ROI digit transit periodicity detection. It can correctly detect the second transit even though the known ROI is not precise. The second one is a Hough-like search for precise second ROI in digit-sequence similarity measure. Experimental results on 70 soccer video clips confirm that our methods can achieve the accurate results.
time recognition live event alert digit transit periodicity detection digit-sequence recognition