Abstract: Sixty-four regions are established on an image sensed picture from a video camera, where evaluating value r.sub.ij, b.sub.ij, and y.sub.ij is obtained by averaging color difference signals R-Y and B-Y and luminance signal Y obtained from an image sensing signal for over 1 field period for each region. When the apparatus determines that the difference in the evaluating values between two adjacent regions does not exceed a predetermined value, that is, when that continuing regions have the same color, the weighing amount of the color evaluating values of a corresponding region is adjusted to limit its effect upon the gain control signals used to adjust the gain of the color signal amplifiers. As a result, the effect of objects of the same color towards white balance adjustment is reduced.

Abstract: Sixty-four regions are established on an image sensed picture from a video camera, where evaluating value r.sub.ij, b.sub.ij, and y.sub.ij is obtained by averaging color difference signals R-Y and B-Y and luminance signal Y obtained from an image sensing signal for over 1 field period for each region. When the apparatus determines that the difference in the evaluating values between two adjacent regions do not exceed a predetermined value, that is, when that continuing regions have the same color, the weighing amount of the color evaluating values of a corresponding region is adjusted to limit its effect upon the gain control signals used to adjust the gain of the color signal amplifiers. As a result, the effect of objects of the same color towards white balance adjustment is reduced.

Abstract: Sixty-Four regions are established on an image sensed picture from a video camera, where evaluating value r.sub.ij, b.sub.ij, and y.sub.ij is obtained by averaging color difference signals R-Y and B-Y and luminance signal Y obtained from an image sensing signal for over 1 field period for each region. When the apparatus determines that the difference in the evaluating values between two adjacent regions do not exceed a predetermined value, that is, when that adjacent regions have the same color, the weighing amount of the color evaluating values of a corresponding region is adjusted to limit its effect upon the gain control signals used to adjust the gain of the color signal amplifiers. As a result, the effect of objects of the same color towards white balance adjustment is reduced.

Abstract: The present invention relates to an automatic focusing apparatus provides an automatic focusing operation free from the effect of light illuminating an object and which operates in a short period of time and with a high reliability. The automatic focusing apparatus includes a focus lens, an image-sensing circuit, a focus motor, a focus evaluating value generating circuit, a focus motor control circuit for intermittently driving focus motor at a timing synchronized with a field cycle, a first subtractor for detecting change in the focus evaluating value during a prescribed time period T1 when focus motor is stopped, and a second subtractor for detecting change in the focus evaluating value during a prescribed time period T2 before and after the movement of focus motor.

Abstract: Auto focus control and/or auto exposure control is carried out by using a luminance signal before gamma correction, before addition of aperture signal but after hand shake correction. Auto white balance control is carried out by using a color signal after hand shake correction. Consequently, precise auto focus control, auto exposure control and/or auto white balance control can be done. The field memory for electronic zooming and/or hand shake correction is also used as a field memory for noise reduction. Consequently, a video signal processing circuit which is inexpensive and simple can be implemented.

Abstract: Auto focus control and/or auto exposure control is carried out by using a luminance signal before gamma correction, before addition of aperture signal but after hand shake correction. Auto white balance control is carried out by using a color signal after hand shake correction. Consequently, precise auto focus control, auto exposure control and/or auto white balance control can be done. The field memory for electronic zooming and/or hand shake correction is also used as a field memory for noise reduction. Consequently, a video signal processing circuit which is inexpensive and simple can be implemented.

Abstract: An automatic focusing apparatus of a video camera automatically matches a focus in response to a video signal obtained from an image sensing circuit. The automatic focusing apparatus detects the level of a high frequency component of the video signal in order to supply a focus evaluating value which takes a maximum value in an in-focus position. A focusing motor controlling circuit performs an automatic focusing operation by a hill-climbing servo system based on the supplied focus evaluating value. A determination is made by employing a fuzzy inference with respect to the initialization of the direction of movement of a lens when the automatic focusing operation starts, the selection of a focusing area from a plurality of areas, and the reactivation of the automatic focusing operation due to a change of an object after once the automatic focusing operation is completed.

Abstract: Sixty-four regions are established on an image sensed picture from a video camera, where each evaluating value r.sub.ij, b.sub.ij, and y.sub.ij is obtained by averaging color difference signals R-Y and B-Y and luminance signal Y obtained from an image sensed signal over 1 field period for each region. When determination is made that luminance evaluating value y.sub.ij out of these evaluating values exceeds a predetermined value, the color evaluating values of the corresponding region are attenuated by a predetermined amount, in response to gain control signals derived from the color difference signals. As a result, the effect of an object of high luminance towards white balance adjustment is reduced.

Abstract: Sixty four regions are established on an image-sensed picture from a video camera, wherein evaluating values r.sub.ij, b.sub.ij and y.sub.ij are obtained by averaging color difference signals R-Y, B-Y and a luminance signal Y obtained from a video signal, respectively, over one field period for each region. When producing a gain control signal for each color difference signal, fuzzy inference is made on the basis of these evaluating values and a weighting amount for each color evaluating value for each region is determined. As a result of the weighting, the contribution degree of each color difference signal in a region, not including a light source color temperature axis on a color plane, is reduced to achieve good white balance adjustment.

Abstract: An automatic exposure adjusting apparatus for use in a video camera automatically adjusts exposure based on a video signal obtained from an image sensing circuit. The automatic exposure adjusting apparatus detects a luminance signal level of the video signal and detects a first mean value which is a simple mean value per unit area of an image sensed picture. The automatic exposure adjusting apparatus also outputs a second mean value weighted every area in accordance with a luminance distribution in the image sensed picture. The automatic exposure adjusting apparatus controls the adjustment of exposure based on the first and second mean values. Such weighting of the luminance level in accordance with the luminance distribution is carried out based on the fuzzy inference.

Abstract: In an image sensing apparatus such as a video camera, an evaluating value for exposure control and determination of a gamma correction value is computed in response to a video signal obtained by an image sensing device for each of a plurality of sampling areas in a sensed image. When an evaluating value which exceeds an allowable range with respect to a predetermined reference value is included in the evaluating values, it is determined that an abnormal luminance portion exists in the corresponding sampling area, so that weighting of the evaluating value is decreased, whereby the effect of such an area on exposure adjustment is restrained. In addition, the picture contrast is computed from the ratio of the maximum value to the minimum value of the evaluating values, whereby the most suitable gamma correction value is determined based on this picture contrast.

Abstract: In an image sensing apparatus such as a video camera, an evaluating value for exposure control and determination of a gamma correction value is computed in response to a video signal obtained by an image sensing device for each of a plurality of sampling areas in a sensed image. When an evaluating value which exceeds an allowable range with respect to a predetermined reference value is included in the evaluating values, it is determined that an abnormal luminance portion exists in the corresponding sampling area, so that weighting of the evaluating value is decreased, whereby the effect of such an area on exposure adjustment is restrained. In addition, the picture contrast is computed from the ratio of the maximum value to the minimum value of the evaluating values, whereby the most suitable gamma correction value is determined based on this picture contrast.

Abstract: In a video camera having an automatic focusing function, a first sampling area in the center of an image sensed picture and a second sampling area around the first sampling area are set. Considering a case in which an auto-focus operation is carried out selecting the first sampling area as a focusing area, when the difference between the newest focus evaluating value and the maximum focus evaluating value becomes one-eighth or more of the maximum focus evaluating value, the second sampling area is selected as the focusing area, to carry out an auto-focus operation. Consequently, an auto-focus operation conforming to the state of an object is carried out. In addition, a priority area for exposure control is selected following selection of the focusing area. Thus, exposure relative to a main object is always maintained most suitably.

Abstract: In a video camera having an automatic iris function and a gamma correcting function, an object evaluating value is calculated based on an exposure evaluating value in a sampling area designated as a priority area, a target luminance level for exposure control is changed according to the relation between this object evaluating value and exposure evaluating values in sampling areas other than the sampling area selected as the priority area, a ratio with which the priority area is weighted in calculating the object evaluating value is changed, and a correction value for gamma correction is further changed. As a result, overexposure and underexposure in a picture are decreased. Furthermore, if an extremely small value is included in exposure evaluating values in sampling areas, the value is previously replaced with a predetermined fixed value, so that the effect of noises or the like on exposure adjustment is decreased.

Abstract: In a video camera having an automatic focusing function, a focus evaluating value is calculated as the sum of first and second focus evaluating values extracted using output of two filters having different cut-off frequencies, and a relative ratio of the first and second focus evaluating value is also calculated. This relative ratio is compared with a predetermined reference value. Considering a case in which the focus evaluating value is below this reference value after an object is brought into focus, even if the focus evaluating value does not change, an auto-focus operation is resumed. On the other hand, considering a case in which the relative ratio is above the reference value, even if the focus evaluating value changes, the auto-focus operation is not resumed. In addition, even if the focus evaluating value reaches a maximum in the auto-focus operation, the auto-focus operation is not terminated if the relative ratio does not reach a predetermined reference value.

Abstract: In an automatic focusing apparatus of a video camera, a first focus evaluating value which steeply changes and a second focus evaluating value which gently changes relative to the position of a lens, are detected in response to a video signal obtained in an image sensing circuit (4). A switching circuit (19) alternately selects the first and second focus evaluating values every one field to apply the same to in-focus state detecting circuits (20, 21), respectively. The in-focus state detecting circuits (20, 21), together with a focusing motor control circuit (10), perform an automatic focusing operation by hill-climbing control. In addition, a calculating circuit (22) calculates the relative ratio of the first focus evaluating value to the second focus evaluating value.