METHOD AND CIRCUIT ARRANGEMENT FOR CHECKING OBJECTS FOR ERRORS USING BINKER-CODED DATA OF AN IMAGE SIGNAL OBTAINED BY RASTER SENSING.

摘要

PURPOSE:To detect a defect which is a part of contour as well in the state of detecting the defect from a video signal, by deciding a defect when the 1st and 2nd level differ and when the 2nd and 3rd levels differ with respect to the binary encoded data of continuous three scanning periods. CONSTITUTION:The video signal 9 from a television camera is binary encoded in a binary encoding circuit 10, and is applied to a shift register 11 having a data shift capacity for one horizontal scanning period. The output is inputted to a shift register 12 having the same shift capacity. Data are fetched from the corresponding shift positions of the registers 11, 12 and are inputted to a comparator 13 by which the data are compared. The circuit 13 compares the data A0-C0 and A1-C1 for 3 picture elements, and when the levels thereof differ, the comparator produces an effective output, thereby starting a comparator 14. The comparator 14 makes comparison after lapse of the period for one horizontal scanning from the point of the time of the comparing operation in the circit 13 and when the level differs, said comparator emits an output signal 16 indicating the presence of a defect. Thus the defects which are a part of contours are detected as well.