Abstract An image processor performs emphasis processings suitable for materials to be copied to produce clear copy outputs. The image processor has a digitizing circuit which outputs a digital signal produced by digitizing an image. The processor further has a first detecting circuit which detects an area of the digital signal including a periodic component, a second detecting circuit which detects a character area of the digital signal, and a smoothing circuit which smoothes the digital signal to output a smoothed signal. Either the digital signal or the smoothed signal is selected and outputted by a changeover circuit according to an output of the first detecting circuit. The output of the changeover circuit is differentiated into a plurality of differentiated signals by a differentiating circuit by use of a plurality of different coefficients. One of the differentiated signals is selected and outputted according to the outputs of the first and second detecting circuits.
An image processor comprising: digitizing means for outputting a digital signal produced by digitizing an image; first detecting means for detecting an area of the digital signal including a periodic component; second detecting means for detecting a character area of the digital signal; smoothing means for smoothing the digital signal to output a smoothed signal; changeover means for outputting either the digital signal or the smoothed signal according to an output of the first detecting means; differentiating means for substantially differentiating an output of the changeover means by use of a plurality of different coefficients to obtain a plurality of differentiated signals; and selecting means for selecting one of the plurality of differentiated signals according to outputs of the first and second detecting means.
Claim 2
Dependent Claim
124 words
An image processor comprising: digitizing means for outputting a digital signal produced by digitizing an image; first detecting means for detecting an area of the digital signal including a periodic component; second detecting means for detecting a character area of the digital signal; smoothing means for smoothing the digital signal to output a smoothed signal; changeover means for outputting either the digital signal or the smoothed signal according to an output of the first detecting means; differentiating means for substantially differentiating an output of the changeover means by use of a plurality of different coefficients to obtain a plurality of differentiated signals; and selecting means for selecting one of the plurality of differentiated signals according to outputs of the first and second detecting means.
Claim 3
Dependent Claim
48 words
An image processor according to claim 1, wherein said first detecting means comprises: differentiating means for differentiating the digital signal; counting means for counting a period of an output of the differentiating means; and determining means for determining that an output of the counting means is substantially constant.
Claim 4
Dependent Claim
86 words
An image processor according to claim 1, wherein said second detecting means comprises: density detecting means for detecting that a density of the digital signal is greater than a predetermined density; color detecting means for detecting that the digital signal has been colored; pattern detecting means for detecting that the digital signal matches a predetermined pattern; and means for outputting a signal representative of a character area when the digital signal is achromatic, is of higher density than the predetermined density and matches the predetermined pattern.
Claim 5
Dependent Claim
44 words
An image processor according to claim 1, wherein said differentiating means comprises: means for emphasizing only the character area; means for emphasizing only the area including the periodic component; and means for emphasizing an area including both the character area and the periodic component.