Imaging apparatus, image processing method, and program

1. An imaging apparatus comprising:

an imaging device; and

a signal processing unit for analyzing an output signal from the imaging device and detecting a defective pixel included in the imaging device, wherein

the imaging device inputs the same subject light on a local area basis including a plurality of pixels of the imaging device, acquires an image signal lower than a pixel resolving power corresponding to the pixel density of the imaging device, and outputs the image signal to the signal processing unit, and

the signal processing unit compares pixel values of the same color pixels included in the local area on a local area basis including a cluster of the plurality of pixels of the imaging device, and detects a defective pixel based on the comparison result;

wherein the signal processing unit executes a process of determining a pixel of interest to be a defective pixel

when a standard deviation of pixel values of the same color pixels included in the local area is larger than a preset threshold value (TH1), and

when a difference absolute value between an average of intermediate pixel values except maximum and minimum pixel values of the same color pixels included in the local area, and a pixel value of the pixel of interest is larger than a preset threshold value (TH2).

2. The imaging apparatus according to claim 1 , wherein the signal processing unit executes a process of determining a pixel of interest to be a defective pixel

when variations in pixel values of the same color pixels included in the local area is large, and

when a difference between an average of intermediate pixel values except maximum and minimum pixel values of the same color pixels included in the local area, and a pixel value of the pixel of interest is large.

3. The imaging apparatus according to claim 1 , wherein the imaging device

includes a photoelectric conversion unit having pixels arranged in a two-dimensional array form, and a microlens placed on an imaging lens side being on a front side of the photoelectric conversion unit, and

has a configuration where incident light via an imaging lens is diffused via the microlens, and the same subject light is received on the local area basis including the plurality of pixels of the imaging device.

4. The imaging apparatus according to claim 3 , wherein the signal processing unit has a configuration where an image on a specific pixel area basis is reconstructed from an image acquired by the imaging device including the microlens and accordingly a specific point-of-view image is generated.

5. The imaging apparatus according to claim 1 , wherein the imaging device has a pixel arrangement where each pixel of a Bayer arrangement including RGB pixels or an arrangement including RGBW pixels is split into four, 2×2 pixels, of the same color.

6. The imaging apparatus according to claim 5 , wherein the imaging device inputs the same subject light on a local area basis including 2×2 same color pixels of the imaging device, acquires an image signal lower than a pixel resolving power corresponding to the pixel density of the imaging device, and outputs the image signal to the signal processing unit.

7. The imaging apparatus according to claim 5 , wherein the imaging device inputs the same subject light on a local area basis including 4×4 or 8×8 pixels of the imaging device, acquires an image signal lower than a pixel resolving power corresponding to the pixel density of the imaging device, and outputs the image signal to the signal processing unit.

8. The imaging apparatus according to claim 1 , wherein the imaging device lets in subject light via a low-resolution imaging lens with a low optical resolving power for forming an optical image with a resolving power lower than a pixel resolving power corresponding to the pixel density of the imaging device and accordingly acquires an image signal lower than the pixel resolving power corresponding to the pixel density of the imaging device, and outputs the image signal to the signal processing unit.

9. An imaging apparatus comprising:

an imaging device; and

a signal processing unit for analyzing an output signal from the imaging device and detecting a defective pixel included in the imaging device, wherein

the imaging device inputs the same subject light on a local area basis including a plurality of pixels of the imaging device, acquires an image signal lower than a pixel resolving power corresponding to the pixel density of the imaging device, and outputs the image signal to the signal processing unit, and

the signal processing unit compares pixel values of the same color pixels included in the local area on a local area basis including a cluster of the plurality of pixels of the imaging device, and detects a defective pixel based on the comparison result, wherein the imaging device

includes a photoelectric conversion unit having pixels arranged in a two-dimensional array form, and an optical low-pass filter placed on an imaging lens side being on a front side of the photoelectric conversion unit, and

has a configuration where incident light via an imaging lens is diffused via the optical low-pass filter, and the same subject light is received on the local area basis including the plurality of pixels of the imaging device.

10. The imaging apparatus according to claim 1 , wherein

the signal processing unit includes a defective pixel correction unit for executing a pixel value correction on a defective pixel, and

the defective pixel correction unit calculates a corrected pixel value of the defective pixel taking, as reference pixels, intermediate pixel values except maximum and minimum pixel values of the pixels of the same color as the defective pixel included in the same local area as the defective pixel.

11. The imaging apparatus according to claim 10 , wherein the defective pixel correction unit

sets a maximum pixel value of the intermediate pixel values as the corrected pixel value of the defective pixel when the defective pixel has the maximum pixel value among the same color pixels in the local area including the defective pixel, and

sets a minimum pixel value of the intermediate pixel values as the corrected pixel value of the defective pixel when the defective pixel has the minimum pixel value among the same color pixels in the local area including the defective pixel.