Patent ID: 9648198
Date: 2017-05-09
CPC Classifications: H04N

Claim:
1. An image processing apparatus for embedding additional information in an image having a plurality of pixels and image information, the apparatus comprising: a generating unit that generates (a) the additional information to be embedded and (b) a bookbinding type of a medium containing the image, the bookbinding type relating to a binding of the medium; a holding unit that holds a plurality of quantization conditions for embedding the additional information, the plurality of quantization conditions including a quantization threshold; a selection unit that segments the image into a plurality of embedding regions, and selects a condition to use in quantization from the plurality of quantization conditions based on the image information, wherein the image information corresponds to (a) an embedding region to be processed and (b) a position of the embedding region to be processed; a quantization condition control unit that controls at least one of the plurality of quantization conditions for a predetermined region of the image based on the bookbinding type generated by the generating unit; an error diffusion processing unit that (a) adds, to a target pixel value, a first quantization error value, (b) compares the quantization threshold and the first quantization error value, (c) produces a second quantization result value, (d) calculates an error between the quantization error value and the second quantization result value, and (e) distributes the error to peripheral pixels of the target pixel; and a separating unit that separates the embedded additional information from the image.