Picture information signal processing apparatus

Claim 2

A picture information signal processing apparatus used in a picture display system including picture information input means (11) for obtaining a picture information signal indicating an input picture by optically scanning the input picture, and picture information output means (16) responsive to the picture information signal to display an output picture corresponding to the input picture, said apparatus for processing the picture information signal so as to pleasantly display the output picture characterized by comprising: picture-type discriminating means (30, 40, 50, 60) for discriminating the type of the input picture on the basis of a distribution, within a pixel array of a specified size, of picture characteristic signals derived from picture information signals each representing one pixel of the input picture; and means (14) responsive to said picture-type discriminating means to select one of the techniques for binary encoding the picture information signals applied to said picture information output means in accordance with the type of input picture.

Claim 3

The picture information signal processing apparatus according to claim 1, characterized in that the picture characteristic signals are each a bi-level signal of a Laplacian signal of the picture information signal indicating one pixel of the input picture.

Claim 4

The picture information signal processing apparatus according to claim 2, characterized in that the Laplacian signal corresponds to the difference between a picture information signal indicating one pixel of the input picture within the pixel array and an averaged signal of the picture information signals corresponding to the pixel array.

Claim 5

The picture information signal processing apparatus according to claim 1, characterized in that the binary encoding techniques include a simple binary encoding technique based on a fixed threshold value and a dithering technique based on variable threshold values.

Claim 6

The picture information signal processing apparatus according to claim 1, characterized in that the picture information signal is a brightness signal.

Claim 7

The picture information signal processing apparatus according to claim 1, characterized in that the input picture includes a first type of character/line picture, a second type of dot picture, and a third type of variable-density picture, and wherein said binary encoding selecting means (14) is responsive to said picture-type discriminating means to select, with respect to the first type of character/line picture, a technique for the simple binary encoding of the picture information signal which is carried out on the basis of a fixed threshold value and, with respect to other types of pictures, a technique of dithering the picture information signal which is carried out on the basis of variable threshold values.

Claim 8

The picture information signal processing apparatus according to claim 6, characterized in that said binary encoding selecting means (14) is arranged to, when the picture information signal has been decided by said picture-type discriminating means to correspond to the first type of picture, receive a picture information signal whose high frequency components are intensified and encode this signal by the simple binary encoding technique, and, when the picture information signal has been decided by said picture-type discriminating means to correspond to the second type of picture, receive an averaged picture information signal and encode this signal by the dithering technique, and, when the picture information signal has been decided by said picture-type discriminating means to corrrespond to the third type of picture, receive a non-processed picture information signal and encode this signal by the dithering technique.

Claim 9

A picture information signal processing apparatus used in a picture display system including a picture information input means (11) for obtaining a picture information signal indicating an input picture by optically scanning the input picture, and picture information output means (16) responsive to the picture information signal to display an output picture corresponding to the input picture, said apparatus for processing the picture information signal so as to pleasantly display the output picture characterized by comprising: Laplacian calculating means (20) connected to receive the picture information signal for calculating a Laplacian thereof for every pixel to produce a Laplacian signal; picture-type discriminating means (30, 40, 50, 60) connected to receive the Laplacian signal from said Laplacian calculating means for comparing a distribution, in a specified pixel array, of two-level signals of Laplacian signals with a previously examined distribution of two-level signals of Laplacian signals for each type of picture, to thereby discriminate the type of input picture; picture information signal compensating means (70) connected to receive the picture information signal for producing a picture information signal whose high frequency components are intensified and a picture information signal averaged with respect to a specified pixel array; picture information signal selecting means (76) responsive to said picture-type discriminating means to select, in accordance with the discriminated picture, one of the picture information signal whose high frequency components are intensified, the averaged picture information signal, and a non-processed picture information signal; and binary encoding selecting means responsive to said picture-type discriminating means (14) for binary encoding the picture information signal applied to said output picture output means on the basis of a fixed threshold value upon receiving the picture information signal whose high frequency components are intensified from said picture information signal selecting means, and dithering the picture information signal applied to said output means upon receiving the averaged picture information signal and the non-processed picture information signal.

Claim 10

A picture information signal processing apparatus used in a picture display system including a picture information input means (11) for obtaining a picture information signal indicating an input picture by optically scanning the input picture, and picture information output means (16) responsive to the picture information signal to display an output picture corresponding to the input picture, said apparatus for processing the picture information signal so as to pleasantly display the output picture characterized by comprising: Laplacian calculating means (20) connected to receive the picture information signal for calculating a Laplacian thereof for every pixel to produce a Laplacian signal; picture-type discriminating means (30, 40, 50, 60) connected to receive the Laplacian signal from said Laplacian calculating means for comparing a distribution, in a specified pixel array, of two-level signals of Laplacian signals with a previously examined distribution of two-level signals of Laplacian signals for each type of picture, to thereby discriminate the type of input picture; picture information signal compensating means (70) connected to receive the picture information signal for producing a picture information signal whose high frequency components are intensified and a picture information signal averaged with respect to a specified pixel array; picture information signal selecting means (76) responsive to said picture-type discriminating means to select, in accordance with the discriminated picture, one of the picture information signal whose high frequency components are intensified, the averaged picture information signal, and a non-processed picture information signal; and binary encoding selecting means responsive to said picture-type discriminating means (14) for binary encoding the picture information signal applied to said output picture output means on the basis of a fixed threshold value upon receiving the picture information signal whose high frequency components are intensified from said picture information signal selecting means, and dithering the picture information signal applied to said output means upon receiving the averaged picture information signal and the non-processed picture information signal.

Claim 11

The picture information signal processing apparatus according to claim 8, characterized in that the Laplacian signal corresponds to the difference between the picture information signal corresponding to one pixel within the pixel array and the averaged signal with respect to the pixel array.

Claim 12

The picture information signal processing apparatus according to claim 8, characterized in that the picture information signal is a brightness signal.

Claim 13

The picture information signal processing apparatus according to claim 8, characterized in that the input picture includes a first type of character/line picture, a second type of dot picture, and a third type of variable-density picture; and wherein said binary encoding selecting means is responsive to said picture-type discriminating means (14) to select, with respect to the first type of character/line picture, a simple binary encoding technique to binary encode the picture information signal on the basis of a fixed threshold value and, with respect to other types of pictures, a dithering technique to binary encode the picture information signal on the basis of variable threshold values.

Claim 14

The picture information signal processing apparatus according to claim 8, characterized in that said picture-type discriminating means includes first circuit means (30) for comparing a distribution, in the specified pixel array, of two-level signals of the Laplacian signals with a previously examined distribution of two-level signals of Laplacian signals for every type of picture; second circuit means (40) connected to receive the Laplacian signals to examine the magnitude of the Laplacian signals; feedback circuit means (60) for storing results of previous decisions made by said picture-type discriminating means; and decision circuit means (50) for totally discriminating the type of input picture in response to said first and second circuit means and said feedback circuit means.

Claim 15

A picture information signal processing apparatus, used in a picture display system including picture information input means for obtaining a picture information signal indicating an input picture by optically scanning the input picture; and picture information output means responsive to the picture information signal to display an output picture corresponding to the input picture, said apparatus for processing the picture information signal so as to pleasantly display the output picture characterized by comprising: circuit means (8) for providing a brightness information signal and first and second color difference signals which corresond to an input picture; Laplacian calculating means (20) connected to receive the brightness information signal for calculating a Laplacian thereof for each pixel to produce a Laplacian signal; picture-type discriminating means (30, 40, 50, 60) connected to receive the Laplacian signal from said Laplacian calculating means for comparing a distribution, in a specified pixel array, of two-level signals of Laplacian signals with a previously examined distribution of two-level signals of Laplacian signals corresponding to each type of picture, to thereby discriminate the type of input picture; brightness information signal compensating means (23, 73, 75) connected to receive the brightness information signal for producing a brightness information signal whose high frequency components are intensified and a brightness information signal averaged with respect to pixels in the specified pixel array; brightness information signal selecting means (76) responsive to said picture-type discriminating means to select, in accordance with the discriminated picture type, one of the brightness information signal whose high frequency components are intensified, the averaged brightness information signal, and a non-compensated brightness information signal; color difference signal compensating means (120a, 120b) connected to receive the first and second color difference signals to average each of them with respect to the pixels in the specified pixel array; color conversion means (12) connected to receive the brightness information signal from said brightness information signal selecting means and the first and second color difference signals from said color difference signal compensating means for converting these signals into first to third color information signals suitable for the display of the output picture; and binary encoding selecting means (14) connected between said color conversion means and said output means and responsive to said picture-type discriminating means for binary encoding the color information signals applied to said output means on the basis of a fixed threshold value when the brightness information signal whose high frequency components are intensifed is selected by said brightness information signal selecting means, and to dither the color information signals applied to said output means when the averaged brightness information signal or the non-compensated brightness information signal is selected.

Claim 16

A picture information signal processing apparatus, used in a picture display system including picture information input means for obtaining a picture information signal indicating an input picture by optically scanning the input picture; and picture information output means responsive to the picture information signal to display an output picture corresponding to the input picture, said apparatus for processing the picture information signal so as to pleasantly display the output picture characterized by comprising: circuit means (8) for providing a brightness information signal and first and second color difference signals which corresond to an input picture; Laplacian calculating means (20) connected to receive the brightness information signal for calculating a Laplacian thereof for each pixel to produce a Laplacian signal; picture-type discriminating means (30, 40, 50, 60) connected to receive the Laplacian signal from said Laplacian calculating means for comparing a distribution, in a specified pixel array, of two-level signals of Laplacian signals with a previously examined distribution of two-level signals of Laplacian signals corresponding to each type of picture, to thereby discriminate the type of input picture; brightness information signal compensating means (23, 73, 75) connected to receive the brightness information signal for producing a brightness information signal whose high frequency components are intensified and a brightness information signal averaged with respect to pixels in the specified pixel array; brightness information signal selecting means (76) responsive to said picture-type discriminating means to select, in accordance with the discriminated picture type, one of the brightness information signal whose high frequency components are intensified, the averaged brightness information signal, and a non-compensated brightness information signal; color difference signal compensating means (120a, 120b) connected to receive the first and second color difference signals to average each of them with respect to the pixels in the specified pixel array; color conversion means (12) connected to receive the brightness information signal from said brightness information signal selecting means and the first and second color difference signals from said color difference signal compensating means for converting these signals into first to third color information signals suitable for the display of the output picture; and binary encoding selecting means (14) connected between said color conversion means and said output means and responsive to said picture-type discriminating means for binary encoding the color information signals applied to said output means on the basis of a fixed threshold value when the brightness information signal whose high frequency components are intensifed is selected by said brightness information signal selecting means, and to dither the color information signals applied to said output means when the averaged brightness information signal or the non-compensated brightness information signal is selected.