Image processing apparatus

Claim 2

An image processing apparatus characterized by comprising: image-area discriminating means (13) for dis­criminating an attribute of an image on the basis of an image signal and outputting a discrimination result as an image-attribution signal; enlargement/reduction processing means (14) for subjecting said image to enlargement/reduction process­ing with a predetermined enlargement/reduction ratio; and filtering means (12), connected to said image-area discriminating means and said enlargement/reduction processing means, which controls a spatial frequency component of said image signal, in accordance with said image-attribution signal and said enlargement/reduction ratio.

Claim 3

An apparatus according to claim 1, character­ized in that said filtering means includes a first two-­dimensional low-pass filter for performing low-pass filtering on an image signal corresponding to one line and outputting a first filtered image signal, a second low-pass filter for performing low-pass filtering on the first filtered image signal and outputting a second fil­tered image signal, Laplacian operation means (103) for acquiring a high frequency signal component of the image and outputting a Laplacian signal, and high frequency emphasis processing means (105) for processing said high frequency signal component and said image signal in accordance with a discrimination result of said image-area discriminating means and said enlargement/­reduction, to subject said image signal to high-­frequency emphasis processing.

Claim 4

An apparatus according to claim 2, character­ized in that said image-area discriminating means com­prises means (13) for discriminating an attribute of an image by a binary pattern of said high frequency sig­nal component.

Claim 5

An apparatus according to claim 2, character­ized in that said high-frequency emphasis processing means (105) comprises coefficient generating means (125) for generating a coefficient determined by said discr­imination result and said enlargement/reduction ratio, multiplying means (121) for multiplying said high fre­quency signal component by said coefficient and outputt­ing a resultant signal, and adder means (122) for adding said resultant signal of said multiplying means and said image signal.

Claim 6

An apparatus according to claim 4, character­ized in that said coefficient generating means includes means (125), having a table with a plurality of coeffi­cients determined by an attribute of an image and an enlargement/reduction ratio, for selectively outputting said coefficients in accordance with said discrimination signal and said enlargement/reduction ratio.

Claim 7

An apparatus according to claim 1, character­ized in that said enlargement/reduction processing means (14) comprises a line memory (301) for storing an image signal, address controlling means (302) for applying a read address signal to said line memory, enlargement/­reduction operation means (303) for performing enlargement/reduction processing on an image signal read out from said line memory (301), and coefficient gener­ating means (304) for outputting an interpolation coef­ficient according to an enlargement/reduction ratio and an address signal.

Claim 8

An apparatus according to claim 1, character­ized in that said one-dimensional spatial filter (15) for performing one-dimensional filtering on an output signal of said enlargement/reduction processing means (14) in accordance with said discrimination signal is connected to said enlargement/reduction processing means (14).

Claim 9

An apparatus according to claim 7, character­ized in that said spatial filter (15) includes averaging means (309) for obtaining a moving average of said out­put signal of said enlargement/reduction processing means and a γ circuit (312) for controlling a γ charac­teristic of an output signal of said averaging means.

Claim 10

An image processing apparatus characterized by comprising: discriminating means (13) for discriminating an attribute of an image on the basis of an image signal and outputting a discrimination signal; response control means (12) for controlling a response of a spatial frequency at a proximity of 1/2 of a Nyquist frequency of said image signal based on said discrimination signal and outputting a response-­controlled image signal; and means (14) for executing enlargement/reduction on said image signal output from said response control means.

Claim 11

An image processing apparatus characterized by comprising: discriminating means (13) for discriminating an attribute of an image on the basis of an image signal and outputting a discrimination signal; response control means (12) for controlling a response of a spatial frequency at a proximity of 1/2 of a Nyquist frequency of said image signal based on said discrimination signal and outputting a response-­controlled image signal; and means (14) for executing enlargement/reduction on said image signal output from said response control means.

Claim 12

An image processing apparatus for processing an image signal corresponding to a predetermined image for each line, characterized by comprising: two-dimensional spatial filtering means (12) for performing two-dimensional spatial filtering on said image signal; image-area discriminating means (13) for discrimi­nating an attribute of said image and outputting a discrimination signal; enlargement/reduction processing means (14) for executing one-dimensional enlargement/reduction on an image signal processed by said two-dimensional spatial filtering means (13); and one-dimensional spatial filtering means (15) for executing one-dimensional spatial filtering on an image signal processed by said enlargement/reduction process­ing means (14) in accordance with said discrimination signal and controlling a spatial frequency response of said image signal; said two-dimensional spatial filtering means (12) including means (105) for controlling a spatial fre­quency response of said image signal in accordance with said discrimination signal, said image-area discriminating means (13) including means for discriminating said attribute in accordance with a processing result of said two-dimensional spatial filtering means (12).

Claim 13

An image processing apparatus for processing an image signal corresponding to a predetermined image for each line, characterized by comprising: two-dimensional spatial filtering means (12) for performing two-dimensional spatial filtering on said image signal; image-area discriminating means (13) for discrimi­nating an attribute of said image and outputting a discrimination signal; enlargement/reduction processing means (14) for executing one-dimensional enlargement/reduction on an image signal processed by said two-dimensional spatial filtering means (13); and one-dimensional spatial filtering means (15) for executing one-dimensional spatial filtering on an image signal processed by said enlargement/reduction process­ing means (14) in accordance with said discrimination signal and controlling a spatial frequency response of said image signal; said two-dimensional spatial filtering means (12) including means (105) for controlling a spatial fre­quency response of said image signal in accordance with said discrimination signal, said image-area discriminating means (13) including means for discriminating said attribute in accordance with a processing result of said two-dimensional spatial filtering means (12).

Claim 14

An enlargement/reduction processing apparatus for a digital image signal, characterized by comprising: accumulating means (600) for accumulating a con­stant determined by a predetermined initial value and a specified enlargement/reduction ratio and outputting a pixel position signal with a precision of a first bit length; means (601) for rounding up a pixel position signal from said accumulating means to a precision of a second bit length smaller than said first bit length to provide a first coarse pixel position signal; means (602) for producing a second coarse pixel position signal from said first coarse pixel position signal and one of a coarse enlargement/reduction ratio obtained by rounding up said specified enlargement/­reduction ratio and a coarse enlargement/reduction ratio obtained by rounding up a reciprocal of said specified enlargement/reduction ratio; first multiplying means (512 to 514) for multiply­ing an original digital image signal by an interpolation coefficient determined by said first and second coarse pixel position signals to provide a plurality of multi­plication results; adder means (515) for adding said plurality of mul­tiplication results; and second multiplying means (516) multiplying an add­ing result from said adder means (515) by a normalizing coefficient determined by said coarse enlargement/­reduction ratio and outputting a digital image signal undergone enlargement/reduction processing.

Claim 15

An enlargement/reduction processing apparatus for a digital image signal, characterized by comprising: accumulating means (600) for accumulating a con­stant determined by a predetermined initial value and a specified enlargement/reduction ratio and outputting a pixel position signal with a precision of a first bit length; means (601) for rounding up a pixel position signal from said accumulating means to a precision of a second bit length smaller than said first bit length to provide a first coarse pixel position signal; means (602) for producing a second coarse pixel position signal from said first coarse pixel position signal and one of a coarse enlargement/reduction ratio obtained by rounding up said specified enlargement/­reduction ratio and a coarse enlargement/reduction ratio obtained by rounding up a reciprocal of said specified enlargement/reduction ratio; first multiplying means (512 to 514) for multiply­ing an original digital image signal by an interpolation coefficient determined by said first and second coarse pixel position signals to provide a plurality of multi­plication results; adder means (515) for adding said plurality of mul­tiplication results; and second multiplying means (516) multiplying an add­ing result from said adder means (515) by a normalizing coefficient determined by said coarse enlargement/­reduction ratio and outputting a digital image signal undergone enlargement/reduction processing.

Claim 16

An enlargement/reduction processing apparatus for a digital image signal, characterized by comprising: accumulating means (600) for accumulating a con­stant determined by a predetermined initial value and a specified enlargement/reduction ratio and outputting a pixel position signal with a precision of a first bit length; means (601) for rounding up a pixel position signal from said accumulating means (600) at a precision of a second bit length smaller than said first bit length to provide a first coarse pixel position signal; means (602) for producing a second coarse pixel position signal from said first coarse pixel position signal and a coarse enlargement/reduction ratio obtained by rounding up said specified enlargement/reduction ratio; multiplying means (512 to 517) for multiplying an original digital image signal by an interpolation coef­ficient determined by said first and second coarse pixel position signals and said coarse enlargement/reduction ratio to provide a plurality of multiplication results; and adder means (515) for adding said plurality of multiplication results and outputting a digital image signal undergone coefficient processing.

Claim 17

An enlargement/reduction processing apparatus for a digital image signal, characterized by comprising: accumulating means (600) for accumulating a con­stant determined by a predetermined initial value and a specified enlargement/reduction ratio and outputting a pixel position signal with a precision of a first bit length; means (601) for rounding up a pixel position signal from said accumulating means (600) at a precision of a second bit length smaller than said first bit length to provide a first coarse pixel position signal; means (602) for producing a second coarse pixel position signal from said first coarse pixel position signal and a coarse enlargement/reduction ratio obtained by rounding up said specified enlargement/reduction ratio; multiplying means (512 to 517) for multiplying an original digital image signal by an interpolation coef­ficient determined by said first and second coarse pixel position signals and said coarse enlargement/reduction ratio to provide a plurality of multiplication results; and adder means (515) for adding said plurality of multiplication results and outputting a digital image signal undergone coefficient processing.