Ikegami Tsushinki Co., Ltd.

Naoki Kashimura

Jun Hattori

Eiji Nakamura

Kazuhiro Ban

Yoshiro Aoyagi

Kazuhiro Kawamura

Takamitsu Sakai

A two-dimensional contour enhancement is performed along a plurality of lines on a two-dimensional frequency characteristic chart, the line intersecting with each other at middle points between successive color cross generating regions and not passing through an origin. Then, the contour enhancement can be carried out in a frequency region of 3-4 MHz in which a visual effect of contour enhancement appears most effective, while the enhancement in the cross color generating regions can be suppressed.

Method and apparatus for correcting contour of color image signal

Solid state image pickup apparatus having test signal generator

An outline compensation circuit comprising: a first coefficient multiplier for reducing a level of an image signal by one half and reversing the polarity thereof; a first delay circuit for delaying by 2.tau. the signal from the first coefficient multiplier; a first adder for adding the signal from the first delay circuit to the image signal; a second delay circuit for delaying the signal from the first adder by 2.tau.; a second adder for adding the signal delayed by the second delay circuit to the signal from the first coefficient multiplier to output a second-order differential signal of the image signal; a first non-linear converter for calculating the square root of the second-order differential signal from the second adder; a subtractor for subtracting the signal from the first delay circuit from the signal from the first coefficient multiplier to output a first-order differential signal of the image signal; an absolute value calculating circuit for calculating the absolute value of the first-order differential signal from the subtractor; a third delay circuit for delaying the signal from the absolute value calculating circuit by .tau.; a second non-linear converter for calculating the square root of the signal from the third delay circuit; and a multiplier for multiplying the signal from the second non-linear converter with the signal from the non-linear converter to output an outline compensation signal, whereby outline compensation can be carried out naturally.

Outline compensation circuit

A registration correction circuit for a solid-state camera having a plurality of solid-state image pickup elements. One of the color video signals produced from the image pickup elements is selected as a reference signal, and pixel data of the color video signals other than the reference signal are electronically moved so that the pixel data of all the color video signals will agree in their positions. Movement of pixels is carried out by using coordinate transformation and interpolation technique: the coordinate transformation is used to shift the pixels by a multiple of 1-pixel pitch; and the interpolation is used to shift the pixels by less than 1-pixel pitch. The spatial frequency components reduced by the interpolation calculations are adaptively enhanced for each pixel in real time.

Registration and contour correction circuit and method for solid-state

An error correction method and circuit for a nonlinear quantization circuit comparing a test signal which is produced from an error correction table by applying an analog reference signal into a nonlinear circuit with reference data that is defined as an output of the error correction table when the nonlinear circuit has no error, and updating the error correction table by the test signal and the reference data when they disagree. The output of the nonlinear circuit is corrected by using the error correction table. The technique is particularly suitable for nonlinear conversion performed by a gamma correction circuit of a color television camera.

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Tokyo, Japan

Naoki Kashimura