Digital camera, image pickup method, and image format conversion method

A digital camera wherein the interval between charge discharging pulses applied to an image pickup device and charge read-out pulses are varied to control the charge accumulation amount of the image pickup device, the digital camera comprising:

• a luminance calculating unit for obtaining subject luminance from imaging signals of the image pickup device;
• and
• a charge accumulation time control unit for forbidding charge discharge of the image pickup device by the charge discharging pulses in the event that the obtained subject luminance is lower than a predetermined value, so as to control the charge accumulation time of the image pickup device in time intervals which are integral multiples of the vertical transfer period.

An image-pickup method with a digital camera wherein the interval between charge discharging pulses applied to an image pickup device and charge read-out pulses are varied to control the charge accumulation amount of the image pickup device, the method comprising:

• obtaining subject luminance from imaging signals of the image pickup device;
• and
• forbidding charge discharge of the image pickup device by the charge discharging pulses in the event that the obtained subject luminance is lower than a predetermined value, so as to control the charge accumulation time of the image pickup device in time intervals which are integral multiples of the vertical transfer period.

An image format conversion method for a digital camera which sequentially performs storing of image signals sequentially image-picked-up and updating of the storage, and performs image format conversion of the stored image signals to generate through-image display image data or recording image data;

• wherein image format conversion is performed such that the number of images of the recording image data generated per unit time is greater than the number of images of through-image display image data generated per unit time.

An image format conversion method for a digital camera which sequentially performs storing of image signals sequentially image-picked-up and updating of the storage, and performs image format conversion of the stored image signals to generate through-image display image data or recording image data;

• wherein image format conversion is performed such that the number of images of the recording image data generated per unit time at the image format converting unit is increased, by reducing the number of images of through-image display image data generated per unit time at the image format converting unit.

An image format conversion method for a digital camera which sequentially performs storing of image signals sequentially image-picked-up and updating of the storage, and performs image format conversion of the stored image signals to generate through-image display image data or recording image data;

• wherein image format conversion is performed such that the number of images of the recording image data generated per unit time in the image format converting unit and the number of images of through-image display image data generated per unit time in the image format converting unit are relatively changed.

An image format conversion method for a digital camera which sequentially performs storing of image signals sequentially image-picked-up and updating of the storage, and performs image format conversion of the stored image signals to generate through-image display image data or recording image data;

• wherein image format conversion is performed such that, at the time of sequentially performing image format conversion of the stored image signals, a first image format conversion for performing sequential image format conversion into both the through-image display image data and the recording image data, and a second image format conversion for performing image format conversion of the stored image signals into only the recording image data, are performed in time-sequence.