Imaging device, image processing method, and program
An imaging device includes an optical system, a plurality of imaging elements, an imaging unit, a comparison unit, and a correction unit. The optical system is configured to disperse light of a subject image. The imaging elements are configured to capture subject images dispersed by the optical system using a rolling shutter method. The imaging unit is configured to shift a slit range, which is between a front curtain and a rear curtain of the rolling shutter method, by at least one line in a sub-scanning direction between the plurality of imaging elements. The comparison unit is configured to calculate a level difference in units of lines between image signals output by the plurality of imaging elements by comparing signal levels of the image signals, and the correction unit configured to correct influence of a flash band on the image signals on the basis of the level difference.
1. An imaging device comprising:
an optical system configured to disperse light of a subject image;
a plurality of imaging elements configured to capture subject images dispersed by the optical system using a rolling shutter method;
an imaging unit configured to shift a slit range, which is between a front curtain and a rear curtain of the rolling shutter method, by at least one line in a sub-scanning direction between the plurality of imaging elements;
a comparison unit configured to calculate a level difference in units of lines between image signals output by the plurality of imaging elements by comparing signal levels of the image signals; and
a correction unit configured to correct influence of a flash band on the image signals on the basis of the level difference.
2. The imaging device of claim 1 , wherein the imaging unit alters exposure start timings of the plurality of imaging elements by a predetermined time.
3. The imaging device of claim 1 , wherein the plurality of imaging elements are disposed such that imaging areas of the plurality of imaging elements are shifted at least one line in the sub-scanning direction on the basis of an image position of each of the dispersed subject images.
4. The imaging device of claim 1 , further comprising a signal delay unit configured to reduce a line shift between images output by the plurality of imaging elements by delaying the image signal of the imaging element of which the slit range passes each of the subject images first, wherein the comparison unit calculates the level difference in each line between the image signals by comparing the plurality of images signals through the signal delay unit.
5. The imaging device of claim 1 , wherein the comparison unit calculates the level difference in units of lines between a signal level (La) of the imaging element (A) of which the slit ranges passes each of the subject images first and a signal level (Lb) of the imaging element (B) of which the slit range passes each of the subject images later, and the correction unit determines that a value obtained by adding the level difference and a correction value (gb) of the imaging element (B) for one line ahead is a correction value (gb) of the imaging element (B), corrects the image signal of the imaging element (B) in units of lines, determines that a correction gain (Gb) for one line ahead is a correction value (ga) of the imaging element (A), and corrects the image signal of the imaging element (A) in units of lines.
6. The imaging device of claim 1 , wherein the plurality of imaging elements are disposed such that phases of pixel arrangements of the plurality of imaging elements are shifted on the basis of an image position of each of the dispersed subject images.
7. The imaging device of claim 1 , wherein the optical system disperses the subject image into a red component, a blue component, and two green components,
the imaging unit shifts the slit range by a predetermined number of lines in the sub-scanning direction between the two imaging elements, which separately receive light of the two green components, and performs scanning,
the comparison unit calculates the level difference in each line between the image signals by comparing signal levels of image signals of the two green components, and
the correction unit corrects the green component of the flash band according to the level difference between the two green components, corrects the red component of the flash band according to a level difference obtained by color-adjusting the level difference with the red component, and corrects the blue component of the flash band according to a level difference obtained by color-adjusting the level difference with the blue component.
8. A method of processing an image signal in an imaging device which includes an optical system configured to disperse light of a subject image, a plurality of imaging elements configured to capture subject images dispersed by the optical system using a rolling shutter method, and an imaging unit configured to shift a slit range, which is between a front curtain and a rear curtain of the rolling shutter method, by at least one line in a sub-scanning direction between the plurality of imaging elements, the method comprising:
a comparison step of calculating a level difference in each line between image signals output by the plurality of imaging elements by comparing signal levels of the image signals; and
a correction step of correcting influence of a flash band on the image signals on the basis of the level difference.