Image processing apparatus and method, and video camera

A still-video camera comprising:

• image pick-up means, which includes a solid-state electronic image sensing device, for outputting a video signal, which represents an image obtained by imaging a subject, from said solid-state electronic image sensing device;
• first amplifier means for amplifying the video signal, which is outputted by said image pick-up means, at a first amplification factor suited to a comparatively bright area of the image, and outputting a first video signal obtained by said first amplification factor;
• second amplifier means for amplifying the video signal, which is outputted by said image pick-up means, at a second amplification factor greater than the first amplification factor and suited to a comparatively dark area of the image, and outputting a second video signal obtained by said second amplification factor;
• first A/D converting means for converting the first video signal into first digital image data corresponding to said first video signal;
• second A/D converting means for converting the second video signal into second digital image data corresponding to said second video signal;
• discriminating means for discriminating a boundary between the comparatively bright area and the comparatively dark area of the image based upon the first digital image data or the second digital image data;
• and
• synthesizing means for producing composite image data using the first digital image data obtained from said first A/D converting means with regard to the comparatively bright area and the second digital image data obtained from said second A/D converting means with regard to the comparatively dark area, said comparatively bright and dark areas being demarcated by the boundary discriminated by said discriminating means.

A still video camera comprising:

• image pick-up means, which includes a solid-state electronic image sensing device, for outputting a video signal, which represents an image obtained by imaging a subject, from said solid-state electronic image sensing device;
• first amplifier means for amplifying the video signal, which is outputted by said image pick-up means, at a first amplification factor suited to a comparatively bright area of the image, and outputting a first video signal obtained by said first amplification factor;
• second amplifier means for amplifying the video signal, which is outputted by said image pick-up means, at a second amplification factor greater than the first amplification factor and suited to a comparatively dark area of the image, and outputting a second video signal obtained by said second amplification factor;
• comparison means for comparing the first video signal with a prescribed threshold level and generating an output when the level of the first video signal exceeds said prescribed threshold level;
• and
• a multiplexer, to which the first and second video signals are entered, for normally selecting and outputting the second video signal and selecting and outputting the first video signal when an output of said comparator is applied thereto.

A digital still video camera comprising:

• image pick-up means, which includes a solid-state electronic image sensing device, for outputting a video signal, which represents an image obtained by imaging a subject, from said solid-state electronic image sensing device;
• first amplifier means for amplifying the video signal, which is outputted by said image pick-up means, at a first amplification factor suited to a comparatively bright area of the image, and outputting a first video signal obtained by said first amplification factor;
• second amplifier means for amplifying the video signal, which is outputted by said image pick-up means, at a second amplification factor greater than the first amplification factor and suited to a comparatively dark area of the image, and outputting a second video signal obtained by said second amplification factor;
• first A/D converting means for converting the first video signal into first digital image data corresponding to said first video signal;
• second A/D converting means for converting the second video signal into second digital image data corresponding to said second video signal;
• and
• synthesizing means for combining the first digital image data and the second digital image data by adding the first and second digital image data at a prescribed ratio.

An image processing method comprising the steps of:

• producing identical first and second image signals from one input image signal;
• amplifying at least one of the first and second image signals in conformity with a difference in brightness between a relatively bright area and a relatively dark area of an image represented by the one input image signal;
• finding a boundary between the relatively bright area and the relatively dark area of the image;
• and
• producing a composite image signal using the first image signal with regard to the relatively bright area and the second image signal with regard to the relatively dark area, said relatively bright and dark areas being demarcated by the boundary found.

An image processing method for a still-video camera comprising the steps of:

• producing identical first and second image signals from one input image signal;
• amplifying at least one of the first and second image signals in conformity with a difference in brightness between a relatively bright area and a relatively dark area of an image represented by the one input image signal;
• and
• combining the first image signal and the second image signal at a prescribed ratio.