Imaging apparatus with dynamic range expanded, a video camera including the same, and a method of generating a dynamic range expanded video signal

A method of generating a combined video signal from an optical image comprising the steps of:

• receiving said optical image and generating a first video signal with a first exposure interval and a second video signal with a second exposure interval substantially at the same time, said second exposure interval being shorter than said first exposure interval, said first and second video signals respectively having first and second effective detection ranges which are different but continuous;
• synchronizing said first video signal with said second video signal every corresponding frames of said first and second video signals;
• detecting an exposure ratio between said first and second exposure intervals;
• adjusting a difference of gains of the synchronized first and second video signals in accordance with said exposure ratio;
• generating a mixing control signal indicative of a mixing ratio of said first and second video signals in accordance with said gain-adjusted first and second video signals;
• and
• generating and outputting said combined video signal from the gain-adjusted first and second video signals in accordance with said mixing control signal and levels of the gain-adjusted first and second video signals to have an expanded dynamic range such that said first effective detection range is connected to said second effective detection range.

An imaging apparatus comprising:

• imaging means including driving means for receiving an optical image and generating a first video signal with a first exposure interval and a second video signal with a second exposure interval substantially at the same time, said second exposure interval being shorter than said first exposure interval, said first and second video signals respectively having first and second effective detection ranges which are different but continuous;
• synchronizing means for synchronizing said first video signal with said second video signal every corresponding frames of said first and second video signals;
• mixing control signal generation means for generating a mixing control signal indicative of a mixing ratio of said first and second video signals in accordance with said first and second video signals;
• video signal generation means for generating a combined video signal from said first and second video signals from said synchronizing means in accordance with said mixing control signal and levels of said first and second video signals to have an expanded dynamic range such that said first effective detection range is connected to said second effective detection range;
• edge enhancement signal generation means for generating an edge enhancement signal from said combined video signal;
• edge enhancement amount control means for controlling an mount of said edge enhancement signal in accordance with said mixing control signal;
• and
• adding means for adding said edge enhancement signal from said gain adjusting means and said combined video signal and outputting an edge-enhanced video signal.

A method of generating a combined video signal from an optical image comprising the steps of:

• receiving said optical image and generating a first video signal with a first exposure interval and a second video signal with a second exposure interval substantially at the same time, said second exposure interval being shorter than said first exposure interval, said first and second video signals respectively having first and second effective detection ranges which are different but continuous;
• synchronizing said first video signal with said second video signal every corresponding frames of said first and second video signals;
• generating a mixing control signal indicative of a mixing ratio of said first and second video signals in accordance with the synchronized first and second video signals;
• generating said combined video signal from the synchronized first and second video signal in accordance with said mixing control signal and levels of said first and second video signals to have an expanded detection range such that said first effective detection range is connected to said second effective detection range;
• generating an edge enhancement signal from said combined video signal;
• controlling an amount of said edge enhancement signal in accordance with said mixing control signal;
• and
• adding the amount-controlled edge enhancement signal and said combined video signal and outputting an edge-enhanced video signal.

An imaging apparatus comprising:

• imaging means including driving means for receiving an optical image and generating a first video signal with a first exposure interval and a second video signal with a second exposure interval substantially at the same time, said second exposure interval being shorter than said first exposure interval, said first and second video signals respectively having first and second effective detection ranges which are different but continuous;
• synchronizing means for synchronizing said first video signal with said second video signal every corresponding frames of said first and second video signals;
• exposure ratio detection means responsive to said imaging means for detecting an exposure ratio between said first and second exposure intervals;
• mixing control signal generation means for generating a mixing control signal indicative of a mixing ratio of said first and second video signals in accordance with said first and second video signals;
• combining means for generating a combined video signal from said first and second video signals from said synchronizing means in accordance with said mixing control signal and levels of said first and second video signals to have an expanded dynamic range such that said first effective detection range is connected to said second effective detection range;
• edge enhancement signal generation means for generating an edge enhancement signal from said combined video signal;
• edge enhancement amount control means for controlling an amount of said edge enhancement signal in accordance with said mixing control signal and said exposure interval ratio;
• and
• adding means for adding said edge enhancement signal from said gain adjusting means and said combined video signal and outputting an edge-enhanced video signal.

A method of generating a combined video signal from an optical image comprising the steps of:

• receiving said optical image and generating a first video signal with a first exposure interval and a second video signal with a second exposure interval substantially at the same time, said second exposure interval being shorter than said first exposure interval, said first and second video signals respectively having first and second effective detection ranges which are different but continuous;
• synchronizing said first video signal with said second video signal;
• detecting an exposure ratio between said first and second exposure intervals;
• adjusting a gain of said second video signal synchronized in accordance with said exposure ratio every corresponding frames of said first and second video signals;
• generating a mixing control signal indicative of a mixing ratio of the synchronized first and second video signals in accordance with the gain-adjusted first and second video signals;
• generating said combined video signal from the synchronized first and second video signals in accordance with said mixing control signal and levels of said first and second video signals to have an expanded detection range such that said first effective detection range is connected to said second effective detection range;
• generating an edge enhancement signal from said combined video signal;
• controlling an amount of said edge enhancement signal in accordance with said mixing control signal and said exposure ratio;
• and
• adding the gain-adjusted enhancement signal from said gain adjusting means and said combined video signal and outputting an edge-enhanced video signal.

An imaging apparatus comprising:

• imaging means including driving means for receiving separated red, green, and blue optical images and generating first red, first green, and first blue video signals with a first exposure interval and second red, second green, and second blue video signals with a second exposure interval substantially at the same time, said second exposure interval being shorter than said first exposure interval, said first red, green, and blue video signals respectively having first red, first green, and first blue effective detection ranges and said second red, green, and blue video signals respectively having second red, second green, and second blue effective detection ranges which are different from said first red, first green, and first blue effective detection ranges respectively but continuous;
• synchronizing means for synchronizing said first red, first green, and first blue video signals with second red, second green, and second blue video signals every corresponding frames of said first red, first green, and first blue video signals and said second red, second green, and second blue video signals;
• exposure interval ratio detection means responsive to said driving means for detecting an exposure ratio between said first and second exposure intervals;
• gain adjusting means for respectively adjusting difference between gains of said first red, first green, and first blue video signals and second red, first, and video signals from said synchronizing means in accordance with said exposure ratio from said exposure interval ratio detection means;
• mixing control signal generation means for generating red, green, and blue mixing control signals respectively indicating mixing ratios between said first red, first green, and first blue video signals and second red, second green, and second blue video signals in accordance with said first red, first green, and first blue video signals and second red, second green, and second blue video signals;
• and
• combining means for generating and outputting combined red, green, and blue video signals from said first red, first green, and first blue video signals and second red, second green, and second blue video signals from said gain adjusting means in accordance with said red, green, and blue mixing control signals and levels of said first red, first green, and first blue video signals and second red, second green, and second blue video signals to have expanded red, green, and blue detection ranges such that said first red, first green, and first blue effective detection ranges are connected to said second red, second green, and second blue video signals, respectively.

A method of generating a combined video signal from an optical image comprising the steps of:

• receiving separated red, green, and blue optical images;
• generating first red, first green, and first blue video signals with a first exposure interval and second red, second green, and second blue video signals with a second exposure interval substantially at the same time, said second exposure interval being shorter than said first exposure interval, said first video signals respectively having first red, first green, and first blue effective detection ranges, said second video signals respectively having second red, second green, and second blue effective detection ranges which are respectively different from first red, first green, and first blue effective detection ranges but continuous;
• synchronizing said first red, first green, and first blue video signals with second red, second green, and second blue video signals every corresponding frames of said first red, first green, and first blue video signals and said second red, second green, and second blue video signals;
• detecting an exposure ratio between said first and second exposure intervals;
• adjusting difference between gains of said first red, first green, and first blue video signals and second red, first, and video signals from said synchronizing means in accordance with said exposure ratio;
• generating red, green, and blue mixing control signals respectively indicating mixing ratios between said first red, first green, and first blue video signals and second red, second green, and second blue video signals in accordance with said first red, first green, and first blue video signals and second red, second green, and second blue video signals;
• and
• generating and outputting combined red, green, and blue video signals from said first red, first green, and first blue video signals and second red, second green, and second blue video signals from said gain adjusting means in accordance with said mixing control signals and levels of said first red, first green, and first blue video signals and second red, second green, and second blue video signals to have expanded red, green, and blue detection ranges such that said first red, first green, and first blue effective detection ranges are connected to said second red, second green, and second blue video signals, respectively.

A video camera comprising:

• a lens unit;
• separation means for separating an optical image beam into separated red, green, and blue optical images;
• imaging means including driving means for receiving separated red, green, and blue optical images and generating first red, first green, and first blue video signals with a first exposure interval and second red, second green, and second blue video signals with a second exposure interval substantially at the same time, said second exposure interval being shorter than said first exposure interval, said first video signals respectively having first red, first green, and first blue effective detection ranges, said first and second video signals respectively having second red, second green, and second blue effective detection ranges which are different from said first red, first green, and first blue effective detection ranges but continuous;
• synchronizing means for synchronizing said first red, first green, and first blue video signals with second red, second green, and second blue video signals every corresponding frames of said first red, first green, and first blue video signals and said second red, second green, and second blue video signals;
• exposure interval ratio detection means responsive to said driving means for detecting an exposure ratio between said first and second exposure intervals;
• gain adjusting means for adjusting difference between gains of said first red, first green, and first blue video signals and second red, first, and video signals from said synchronizing means in accordance with said exposure ratio from said exposure interval ratio detection means;
• mixing control signal generation means for generating red, green, and blue mixing control signals respectively indicating mixing ratios between said first red, first green, and first blue video signals and second red, second green, and second blue video signals in accordance with said first red, first green, and first blue video signals and second red, second green, and second blue video signals;
• and
• combining means for generating and outputting combined red, green, and blue video signals from said first red, first green, and first blue video signals and second red, second green, and second blue video signals from said gain adjusting means in accordance with said mixing control signals and levels of said first red, first green, and first blue video signals and second red, second green, and second blue video signals to have expanded red, green, and blue detection ranges such that said first red, first green, and first blue effective detection ranges are connected to said second red, second green, and second blue video signals, respectively.