Title:
【発明の名称】画素密度変換装置
Document Type and Number:
Japanese Patent JP2714141
Kind Code:
B2
Abstract:
PURPOSE:To suppress an approximate error and to reduce the deterioration of picture quality by limiting the variable power rate of a means by a projection method provided also with a means which multiplies variably the picture element density by a method other than the projection method within a prescribed range. CONSTITUTION:The picture element density of image data is converted by increasing or decreasing the number of picture elements of a binary image by processing the data with a majority processing part 2 and a thinning processing part 3 which perform a processing based on the mean value of the black and white density of the picture element. The picture element density of converted image data is further converted with a projection method processing part 5 via a multiplexer, thereby, the number of picture elements can be increased or decreased, then, an image can be multiplied variably. At such the case, by setting the variable power rates of the processing parts 2 and 3 with a setting part so as to set the variable power rate at >=0.6 by the processing part 5, the increment of the approximate error according to the reduction of the variable power rate by the processing part 5 can be suppressed, which enables the conversion of the picture element density to be performed at high speed without generating the deterioration of the picture quality.
Inventors:
Yasunori Hashimoto
Kato Masami
Kato Masami
Application Number:
JP14547389A
Publication Date:
February 16, 1998
Filing Date:
June 09, 1989
Export Citation:
Assignee:
Canon Inc
International Classes:
G06T3/40; H04N1/387; (IPC1-7): G06T3/40; H04N1/387
Domestic Patent References:
| JP61140270A |
Attorney, Agent or Firm:
Yasunori Otsuka (1 person outside)