| 摘要 |
<p>PURPOSE: To improve coding efficiency by performing a coding by a binary coding method, deciding whether a multivalued signal should be coded by a multivalue based on a prescribed criteria or not, performing a coding by a prescribed multivalued coding method when the coding should be performed by the multivalue and eliminating the multivalued coding when the coding should not be performed by the multivalue. CONSTITUTION: When the intermediate level value of the transmittance of a multivalue signal 1 can be ignored, the multivalue signal 1 is threshold processed because the signal 1 is inputted in a thresholding means 2 and is compared with the threshold of the thresholding means 2 and a binary signal 3 is outputted from the thresholding means 2. When the binary signal 3 is inputted in a binary coding means 4, a binary coding is performed for the signal by an MR coding and a coding signal 5 is outputted from the binary coding means 4. Namely, in the first coding, the codings when transmittance is 100% or the other cases are performed, and, in the second coding, the intermediate level value of transmittance is regarded to be an ignored one when the the value is small and the coding is eliminated.</p> |
