| 摘要 |
<p>To locate a preselected symbol in a two-dimensional image, a single main probe (10) of a line of pixels extending across a boundary box of the field of view is conducted to find a first color transition. Once a first transition is found, a second probe (20) is conducted to search in a second line of pixels for a second color transition. If no second color transition is found, the main probe resumes searching along the line of pixels for another first color transition from where it had stopped. If a second transition is found, then a plurality of additional probes (30) are conducted to search for transitions in respective third lines of pixels to locate and define the edge located by the main and second probes. The located and defined portion of the symbol is tested for validity.</p> |
