| 摘要 |
PURPOSE:To enable execution of accurate evaluation even when a measuring magnification is lowered, by generating an address in a prescribed sphere of a sample converted into video signals and by comparing the lightness of a pixel corresponding thereto with a predetermined threshold. CONSTITUTION:The density of each pixel of a sample image constituting video signals for one screen is converted into digital density information by an A/D converter 322 and it is taken in by a frame memory 323. An address memory 324 stores addresses provided at prescribed intervals longitudinally and laterally in a prescribed sphere of a sample, and control CPU 321 reads out an address value corresponding to a cleared address counter from this memory 324 and reads out density information corresponding thereto from the memory 323. When this density information is found to be lower than a predetermined threshold by comparison, it is judged that there is a nonmetallic inclusion on the sample corresponding to the pixel, and when it is higher, it is judged that there is a metal material thereon. This is counted by a counter 325 and outputted as an evaluation value. Accordingly, a grid line is dispensed with and execution of accurate evaluation is enabled even when a measuring magnification is lowered to about 200 magnifications. |
