EP0920196A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and imaging apparatus for generating a dynamic range expanded video signal
Assignee: Panasonic Holdings Corp
•
Filing: 1998-11-18
•
Granted: —
•
Expires: 2018-11-18
Abstract
Abstract An imaging circuit generates a first video signal with a first exposure interval and a second video signal with a second exposure interval substantially at the same time, the second exposure interval being shorter than the first exposure interval, the first and second video signals respectively having first and second dynamic ranges which are different but continuos. The first video signal is synchronized with the second video signal. An exposure ratio between the first and second exposure intervals is detected. A gain of the second video signal is adjusted according to the exposure ratio. A combined video signal is generated from the first and second video signals according to a mixing control signal indicative of a mixing ratio between first and second video signals and levels of the first and second video signals to have an expanded dynamic range such that the first dynamic range is connected to the second dynamic range with difference in gains of the first and second video signals adjusted for linearity. An edge enhancement signal may be gain-controlled or coring-controlled according to the mixing control signal or the exposure ratio. The similar apparatus and method for color signals are also disclosed. The output dynamic range for a display is limited by a non-linear process.
Inventors
- 👤 Masayuki Serizawa
- 👤 Kenji Tabei
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 11:02
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/70; H04N23/80; H04N23/84; H04N25/00; H04N25/50; H04N25/57; H04N25/58; H04N25/587; H04N25/589; H04N2209/00; H04N2209/04; H04N2209/041; H04N2209/048; H04N2209/049
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
257 words
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 interval ratio detection means responsive
to said driving means for detecting an exposure ratio
between said first and second exposure intervals; gain adjusting means responsive to said first and
second video signals from said synchronizing means for
adjusting a difference between gains of said first and
second 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 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 from said gain
adjusting means; and combining means for generating and outputting a
combined video signal from said first and second video
signals from said gain adjusting means 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.
Claim 2
Independent Claim
207 words
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.
Claim 3
Dependent Claim
245 words
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.
Claim 4
Independent Claim
216 words
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.
Claim 5
Dependent Claim
47 words
The imaging apparatus as claimed in claim 3, further
comprising: generation means for generating a coring amount control
signal in accordance with said mixing control signal; and coring means for effecting a coring operation to the
edge enhancement signal in accordance with said coring
amount control signal.
Claim 6
Dependent Claim
43 words
The method as claimed in claim 4, further comprising
the steps of: generating a coring amount control signal in
accordance with said mixing control signal; and effecting a coring operation to said edge
enhancement signal in accordance with said coring amount
control signal.
Claim 7
Dependent Claim
269 words
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.
Claim 8
Independent Claim
251 words
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.
Claim 9
Dependent Claim
63 words
The imaging apparatus as claimed in claim 7, further
comprising: coring amount control signal generation means for
generating a coring amount control signal in accordance
with said mixing control signal and said exposure ratio;
and coring means for effecting a coring operation to the
edge enhanced signal in accordance with said coring amount
control signal from said coring amount control signal
generation means.
Claim 10
Dependent Claim
47 words
The method as claimed in claim 8, further comprising
the steps of: generating a coring amount control signal in
accordance with said mixing control signal and said
exposure ratio; and effecting a coring operation to the edge enhancement
signal in accordance with said coring amount control signal.
Claim 11
Dependent Claim
411 words
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.
Claim 12
Dependent Claim
113 words
The imaging apparatus as claimed in claim 11, further
comprising: maximum detection means for detecting a maximum
level among said combined red, combined green. and combined
blue video signals for one frame period; and non-linear processing means responsive to display
dynamic range data for generating and outputting red, green,
and blue display signals having non-linear characteristics
such that said maximum level is made equal to or less than
said display dynamic range data when the detected maximum
level is larger than said display dynamic range data and
outputting said combined red, green, and blue video signal
as they are when the detected maximum level is not larger
than said display dynamic range data.
Claim 13
Independent Claim
367 words
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.
Claim 14
Dependent Claim
111 words
The method as claimed in claim 13, further comprising
the steps of: detecting a maximum level among said combined red,
third green, and third blue video signals for one frame
period; and generating and outputting red, green, and blue
display signals having non-linear characteristic in
accordance with display dynamic data and said maximum level
such that said maximum level is made equal to or less than
said display dynamic range data when the detected maximum
level is larger than said display dynamic range data and
outputting said combined red, green, and blue video signal
as they are when the detected maximum level is not larger
than said display dynamic range data.
Claim 15
Dependent Claim
417 words
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.
Claim 16
Dependent Claim
112 words
The camera as claimed in claim 15, further comprising: maximum detection means for detecting a maximum
level among said combined red, third green, and third blue
video signals for one frame period; and non-linear processing means responsive to display
dynamic range data for generating and outputting red, green,
and blue display signals having non-linear characteristic
such that said maximum level is made equal to or less than
said display dynamic range data when the detected maximum
level is larger than said display dynamic range data and
outputting said combined red, green, and blue video signal
as they are when the detected maximum level is not larger
than said display dynamic range data.
Claim 17
Dependent Claim
38 words
The imaging apparatus as claimed in claim 1, wherein
said gain adjusting means adjusts said difference between
gains of said first and second video signals from said
synchronizing means to provide a linearity in the expanded
detection range.
Claim 18
Dependent Claim
72 words
The imaging apparatus as claimed in claim 1, further
comprising: 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 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.
Claim 19
Dependent Claim
36 words
The imaging apparatus as claimed in claim 18, wherein
said edge enhancement amount control means controls said
amount of said edge enhancement signal in accordance with
said exposure ratio in addition to said mixing control
signal.
Claim 20
Dependent Claim
101 words
The imaging apparatus as claimed in claim 1, further
comprising: edge enhancement signal generation means for
generating an edge enhancement signal from said combined
video signal; coring amount control signal generation means for
generating a coring amount control signal in accordance
with said mixing control signal; coring means for effecting a coring operation to the
edge enhanced signal in accordance with said coring amount
control signal from said coring amount control signal
generation means; and adding means for adding said edge enhancement signal
from said edge enhancement signal generation means and said
combined video signal and outputting an edge-enhanced video
signal.
Claim 21
Dependent Claim
35 words
The imaging apparatus as claimed in claim 20, wherein
said coring amount control signal generation means
generates said coring amount control signal in accordance
with said exposure ratio in addition to said mixing control
signal.
References Cited (Backward Citations)
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