IMAGING APPARATUS, IMAGING PROCESSING METHOD, AND IMAGING CONTROL PROGRAM

• US 20090153699A1
• Filed: 11/17/2008
• Published: 06/18/2009
• Est. Priority Date: 12/18/2007
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: SATOH, Yutaka, Asoma, Akira
• Granted Patent: US 8,154,619 B2
• Time in Patent Office: Days
• US Class Current: 348/229.100
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/58 involving two or more exposures
• CPC Class Codes: H04N 25/589 with different integration times, e.g. short and long exposures
• CPC Class Codes: H04N 25/715 using frame interline transfer [FIT]

Abstract

An imaging apparatus includes: an imaging device outputting, during a unit period of time, a long-exposure-time image signal having a relatively long exposure time and a short-exposure-time image signal having a relatively short exposure time; a first clipping processing mechanism clipping a part not lower than a first signal level of a luminance signal obtained from the long-exposure-time image signal; a second clipping processing mechanism clipping a part not higher than a second signal level of a luminance signal obtained from the short-exposure-time image signal; and a signal processing mechanism generating a synthesized image signal having a dynamic range wider than dynamic ranges of both of the image signals by synthesizing the clipped image signals, wherein the second signal level is not lower than a signal level obtained by dividing the first signal level by a ratio in time of the long exposure time to the short exposure time.

Claims

1. An imaging apparatus comprising:

an imaging device outputting, during a unit period of time, a long-exposure-time image signal having a long-exposure-time period being a relatively long exposure time and a short-exposure-time image signal having a short-exposure-time period being a relatively short exposure time;

first clipping processing means for clipping a part not lower than a first signal level of a luminance signal obtained from the long-exposure-time image signal;

second clipping processing means for clipping a part not higher than a second signal level of a luminance signal obtained from the short-exposure-time image signal; and

signal processing means for generating a synthesized image signal having a dynamic range wider than both of dynamic ranges of the long-exposure-time image signal and the short-exposure-time image signal by synthesizing the long-exposure-time image signal having been subjected to the clipping processing by the first clipping processing means and the short-exposure-time image signal having been subjected to the clipping processing by the second clipping processing means,

wherein the second signal level is not lower than a signal level obtained by dividing the first signal level by a ratio in time of the long exposure time to the short exposure time.

2. The imaging apparatus according to claim 1, further comprising:

color-signal processing means for obtaining a synthesized color signal by synthesizing a color signal obtained from the long-exposure-time image signal and a color signal obtained from the short-exposure-time image signal,

wherein the color-signal processing means does not use the short-exposure-time image signal having a signal level not higher than a clipping level of a short-exposure-time luminance signal by the second clipping processing means.

3. A method of controlling imaging, comprising the steps of:

controlling an imaging device so that the imaging device outputs, during a unit period of time, a long-exposure-time image signal having a long-exposure-time period being a relatively long exposure time and a short-exposure-time image signal having a short-exposure-time period being a relatively short exposure time;

clipping a part not lower than a first signal level of a luminance signal obtained from the long-exposure-time image signal;

clipping a part not higher than a second signal level of a luminance signal obtained from the short-exposure-time image signal; and

synthesizing the clipped long-exposure-time image signal and the clipped short-exposure-time image signal so that a synthesized image signal having a dynamic range wider than both of dynamic ranges of the long-exposure-time image signal and the short-exposure-time image signal is generated,

wherein the second signal level is not lower than a signal level obtained by dividing the first signal level by a ratio in time of the long exposure time to the short exposure time.

4. An imaging control program for causing a computer to perform a method of controlling imaging, the imaging control program comprising the steps of:

controlling an imaging device so that the imaging device outputs, during a unit period of time, a long-exposure-time image signal having a long-exposure-time period being a relatively long exposure time and a short-exposure-time image signal having a short-exposure-time period being a relatively short exposure time;

clipping a part not lower than a first signal level of a luminance signal obtained from the long-exposure-time image signal;

clipping a part not higher than a second signal level of a luminance signal obtained from the short-exposure-time image signal; and

synthesizing the clipped long-exposure-time image signal and the clipped short-exposure-time image signal so that a synthesized image signal having a dynamic range wider than both of dynamic ranges of the long-exposure-time image signal and the short-exposure-time image signal is generated,

wherein the second signal level is not lower than a signal level obtained by dividing the first signal level by a ratio in time of the long exposure time to the short exposure time.

5. An imaging apparatus comprising:

an imaging device outputting, during a unit period of time, a long-exposure-time image signal having a long-exposure-time period being a relatively long exposure time and a short-exposure-time image signal having a short-exposure-time period being a relatively short exposure time;

a first clipping processing mechanism clipping a part not lower than a first signal level of a luminance signal obtained from the long-exposure-time image signal;

a second clipping processing mechanism clipping a part not higher than a second signal level of a luminance signal obtained from the short-exposure-time image signal; and

a signal processing mechanism generating a synthesized image signal having a dynamic range wider than both of dynamic ranges of the long-exposure-time image signal and the short-exposure-time image signal by synthesizing the long-exposure-time image signal having been subjected to clipping processing by the first clipping processing mechanism and the short-exposure-time image signal having been subjected to clipping processing by the second clipping processing mechanism,

wherein the second signal level is not lower than a signal level obtained by dividing the first signal level by a ratio in time of the long exposure time to the short exposure time.