CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is based on PCT filing PCT/JP2019/036082, filed Sep. 13, 2019, which claims priority to JP 2018-189010, filed Oct. 4, 2018, the entire contents of each are incorporated herein by reference.

TECHNICAL FIELD

This technology relates to an image processing device, an image processing method, and a program, and enables detection of a fading state of a color filter with precision.

BACKGROUND ART

For a color filter mounted on the front surface of an image capturing element, it is known that fading is accelerated by long-time exposure and the performance deteriorates. Therefore, in Patent Document 1, when cumulative exposure time, which is the sum of time when a shutter is open, exceeds limit exposure time of the image capturing element, notification about this fact is made.

CITATION LIST

Patent Document

Patent Document 1: Japanese Patent Application Laid-Open No. 2011-103513

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In that connection, when capturing a moving image, for example, in a case where a dark scene is captured and in a case where a bright scene is captured, an amount of incident light of the image capturing element is different between the two cases even if image capturing time is the same. Therefore, as shown in Patent Document 1, the fading state cannot be determined with precision by using cumulative exposure time, which is the sum of time when the shutter is open.

Therefore, an object of this technology is to provide an image processing device, an image processing method, and a program that can detect the fading state of a color filter with precision.

Solutions to Problems

A first aspect of this technology is

an image processing device including

a fading information generation unit configured to generate fading information indicating fading of a color filter on the basis of comparison target information based on an image signal generated by an image capturing unit using the color filter and fading determination reference information.

In this technology, color information generated from the image signal generated by the image capturing unit using the color filter is used as the comparison target information. Furthermore, color information in a case where there is no fading of the color filter is used as the fading determination reference information. This comparison target information is compared with the fading determination reference information, and the fading information is generated on the basis of a comparison result. In the Image processing device, for example, an image area of a fading determination object is detected as a comparison area on the basis of the image signal generated by the image capturing unit, and the color information generated from the image signal of the comparison area is used as the comparison target information. Furthermore, detection of the comparison area may be performed according to a fading level estimated on the basis of the comparison result, and detection of the comparison area may be performed within an image area set in advance.

Furthermore, the image capturing unit may be provided with a color component pixel provided with a color filter and a reference pixel in which fading does not occur. The color information generated from the image signal generated in the color component pixel may be used as the comparison target information, and the color information generated on the basis of a signal of the reference pixel may be used as the fading determination reference information. The reference pixel is, for example, a pixel provided with no color filter, or a pixel provided with a spectral filter instead of the color filter.

Comparison information indicating the comparison result of the comparison target information and the fading determination reference information is accumulated, and on the basis of the accumulated comparison information, the fading information indicating that the fading level of the color filter exceeds a predetermined level or the fading level of the color filter is generated.

Furthermore, illuminance information generated on the basis of the image signal, or the illuminance information and environmental information when the image signal is generated are accumulated. The accumulated illuminance information or illuminance information and environmental information are used as the comparison target information. Information indicating the relationship between the fading level of the color filter and an accumulation result of the illuminance information or environmental information is used as the fading determination reference information. On the basis of the comparison target information and the fading determination reference information, the fading information indicating that the fading level of the color filter exceeds a predetermined level or the fading level of the color filter is generated.

A second aspect of this technology is

an image processing method including

generating, by a fading information generation unit, fading information indicating fading of a color filter on the basis of comparison target information based on an image signal generated by an image capturing unit using the color filter and fading determination reference information.

A third aspect of this technology is a program for causing a computer to execute generation of information regarding a color filter used in an image capturing unit, the program configured to cause the computer to perform:

generating comparison target information on the basis of an image signal generated by the image capturing unit using the color filter; and

generating fading information indicating fading of the color filter on the basis of the comparison target information and fading determination reference information.

Note that the program of the present technology is, for example, a program that can be provided by a storage medium provided in a computer-readable format, communication medium, for example, a storage medium such as an optical disk, a magnetic disk, and a semiconductor memory, or a communication medium such as a network to a general-purpose computer that can execute various program codes. By providing such a program in a computer-readable format, processing according to the program can be implemented on the computer.

