ApplicationNo. 515075 filed on 10/15/1974
US Classes:382/275, Artifact removal or suppression (e.g., distortion correction)382/271Based on the results of a count
ExaminersPrimary: Boudreau, Leo H.
Attorney, Agent or Firm
International ClassG06K 9/38 (20060101)
Foreign Application Priority Data1973-10-17 JA
AbstractA pattern preliminary processing system wherein high and low frequency noise other than the pattern signal from a pick-up tube are eliminated by a filtering circuit thereby to "relieve" the pattern against the background and the thus obtained pattern signal is tri-valued into signals of high, medium and low levels by means of a processing circuit having two different threshold values, and then the signal of the medium level is converted into a signal of high or low level with reference to peripheral information thereby to finally bi-value the pattern signal.