Hitachi Denshi Kabushiki Kaisha

Hitachi-kokusai Electric Inc.

Kazuhiro Tanabe

Yoshizumi Eto

Nobuo Murata

Hiroyuki Nisikawa

Toshimichi Shimizu

Both a high signal-to-noise ratio and wide dynamic range of the output video signal of a one-CCD color television camera are realized. An image signal processing apparatus of an imaging device using a solid-state image sensor in which different color filters are arranged includes an amplifying unit which amplifies color signals from the solid-state image sensor with a predetermined amplification factor, a separating unit which separates the color signals amplified by the amplifying unit into individual color signals, a white balance adjusting unit which subjects the separated color signals to white balance adjustment, a level detecting unit which detects a saturation level from the color signals subjected to the white balance adjustment depending on the amplification factor of the amplifying unit, a correction signal generating unit which generates correction signals from the other color signals than the color signal from which the saturation level is detected by the level detecting unit, and a first adding unit which adds the correction signals to the color signals subjected to the white balance adjustment.

Image processing apparatus and image processing method

An image pickup apparatus is equipped with an image pickup device in which pixels coated with different color filters are arranged. Further, the image pickup apparatus includes a separation unit that separates a video signal outputted from the pixels coated with the different color filters into three color image signals; an adjustment signal generation unit for generating a color balance adjustment signal and a hue adjustment signal from the separated three color image signals; and an adjustment unit for adjusting the video signal outputted from the pixels coated with the different color filters by using the color balance adjustment signal and hue adjustment signal generated by the adjustment signal generation unit.

Image pickup apparatus

When digital signals are to be transmitted between a camera unit and a camera control unit, the distance of their transmission depends on the frequency at which the digital signals are transmitted. The higher the frequency of the digital signals is, the greater the cable attenuation is, inviting deterioration of the signals. Therefore, with a view to matching the quantity of transmitted signals with the length of the transmission path and thereby achieving high quality of signal transmission, a method of signal transmission for a signal transmission apparatus wherein a camera unit and a camera control unit for controlling the camera unit are connected by a transmission path and a video signal, an audio signal and a control signal are digitized, time division multiplexed and transmitted between the camera unit and the camera control unit, has a step of measuring the value of delay of signals transmitted over the transmission path, and each of the camera unit and the camera control unit performs a step of controlling the data quantity of signals to be delivered to the transmission path on the basis of the measured value of delay.

Method of a signal transmission for controlling a quantity of data transmitted and a signal transmission apparatus therefor

A tone correction apparatus corrects the tone of an input color image signal independently of each of a plurality of hue areas divided by a plurality of standard axes passing through a plurality of standard colors set on a hue coordinate system. The tone correction apparatus judges whether the hue of an input color image signal belongs to which one of first and second auxiliary hue areas, the first and second auxiliary hue areas being one of the plurality of hue areas divided by an auxiliary standard axis of an auxiliary standard color, and if the hue of the input color image signal is judged to belong to one of the first and second auxiliary hue areas, independently performs tone correction of the input color image signal with respect to color components along one standard axis of the plurality of standard axes surrounding the one auxiliary hue area to which the hue of the input color image signal belongs and along the auxiliary standard axis.

Tone correction apparatus for digital color image signal

In a video signal transmission method and system wherein a signal containing a video signal is bidirectionally transmitted and received in a substantially real time in video appliances coupled via a transmission path to each other, a digital signal containing a digital video signal is time-compressed, and a transmission operation is controlled in such a manner that a transmission period and a no transmission period are alternately produced in a preselected period. Then, the time-compressed digital signal is transmitted to the transmission path during the transmission period, whereas another digital signal transmitted via the transmission path from the video appliance on the counter side is received during the no transmission period. Then, the received digital signal is time-expanded to reproduce the original signal.

Method for bidirectionally transmitting digital video signal and digital

A fault diagnosis method of a television camera apparatus. A fault diagnosis of a television camera apparatus is divided into a plurality of diagnosing processes, and when the result of the fault diagnosis in each fault diagnosing process is diagnosed as abnormal, the fault diagnosis of the next fault diagnosing process is not executed. A microprocessor is provided in each of a camera head and a camera control unit, and each microprocessor independently executes the fault diagnosis and transmits the result of the fault diagnosis to the other. The camera head and the camera control unit constituting the television camera apparatus are connected with each other by a transmission line, and a test signal for diagnosis generated and transmitted by the camera head is received by the camera control unit so that the test signal for diagnosis so received is compared with an expected value corresponding to this test signal so as to execute the fault diagnosis. In the television camera apparatus having such a construction, a plurality of kinds of test signals for diagnosis are prepared in advance, and when these test signals are transmitted, information associated with each test signal is transmitted in combination. Comparison is then made between each test signal for diagnosis so received and the expected value corresponding to this test signal, and various fault diagnoses of the television camera apparatus are executed.

Fault diagnosis method of television camera apparatus

In an automatic color-balance setup system for a color TV camera, a chart board having a white pattern, a black pattern and a gray pattern is imaged by the color TV camera for the purpose of color balance adjustment. The image signal data appearing at the output of the TV camera are analyzed to compute and determine the white level, the black level and the gray level, and the locations of the image signal data corresponding to the individual levels, measurement regions for the white level, the black level and the gray level are automatically determined color balance automatic setup.

Growing community of inventors

Iruma, Japan

Kazuhiro Tanabe