A video camera is operated to obtain a very rapid change in magnification. A target degree of magnification is achieved by rapid change in an electronic zoom factor provided by an image signal processing circuit. Either before or after the change in electronic zoom factor, simultaneous off-setting changes are carried out in the electronic zoom factor and in a mechanical zoom factor provided by the camera's optical system. The simultaneous off-setting changes in the two zoom factors occur at a rate consistent with practical operation of the mechanical drive components for the camera's optical system.

An image processing apparatus that eliminates a complicated operation when a document image is input. The apparatus has an image input device for inputting a document image. A detection device detects displacement of the document image input by the input device. A determination device determines the input conditions of the image input device when the displacement detected by the detection device is not greater than a predetermined value. A control device controls the input device based on the input conditions determined by the determination device so as to cause the input device to input the document image.

An image processing apparatus for maintaining image size in the course of zooming comprises an input part for inputting an image signal and focusing the image in an image plane, a detection part for setting a detection area and detecting a motion vector of the image in the detection region in said image plane, and a changing part for changing an angle of view of the image according to an output of the detection part. The changing part includes a zoom motor for changing the position of a zoom lens.

An image pick-up apparatus having an optical zoom mechanism and an electronic zoom mechanism, wherein the optical zoom mechanism and the electronic zoom mechanism are adjusted in accordance with information on a position and size of an area recognized as an object (a human face). An image pick-up apparatus in which the control gain for restoring the rotating lens barrel to a reference position is increased by static detection of a housing, thereby attaining a compatibility between a high vibration-proofing performance and a high-accuracy origin restoration. A motion vector detection apparatus, in which by making the motion vector detection area movable, a motion vector is detected without any feeling of disorder regardless of the image pattern. An image swing correction apparatus is also disclosed in which the phase of a read clock of a video memory is adjusted in accordance with the result of detection of a time-base error of the video signal, and read out by a clock of regular intervals. The time base of the video signal is thus corrected while at the same time moving the read position of the video memory in accordance with the result of detection of the swing amount of the whole image, thereby correcting the swing of the whole image.

A method for controlling a camera using an image compression algorithm. A motion region and a motionless region are determined with respect to an input image based on a motion vector of a macro block which is for the generation of compressed data from the input image. A center value and a size of a moving object is estimated from the motion region. According to the center value and the size of the moving object, the camera is controlled to track and photograph the moving object. Accordingly, a central processing unit of the moving object tracking system is relieved of substantial processing load, and the processing speed of the system is improved.