| 摘要 |
PROBLEM TO BE SOLVED: To enable the detection of the location of a part with reliability by generating the frequency distribution of data values indicating the edge of a part from image pickup data and obtaining threshold values for detecting the location of edges from the number of the edges and the frequency distrubution obtained from part data. SOLUTION: The number of the edges e of a part terminal which should exist is calculated in reference to the data of the part before image pickup. Next to this, the part is photographed for image pickup and quantized at every pixel, and the image pickup data is expressed in density values from e.g. 0 to 255. A different filter processing expressed in f(n+1)-f(n-1) is performed on the obtained density map, and on the basis of its result a frequency distribution is generated. The maximum value of the result of a different filter in the frequency distribution and the sum of the frequency of values succeeding this are sequentially obtained, the value in the vicinity of the data value of the frequency at the time when the sum becomes equal to the edge number e is set to a threshold value. By this method, it is possible to set a threshold value suitable for detecting the location of the edges of part terminals. |
