Image pickup device and signal processing method
The present invention provides an image pickup device and a signal processing method which can reduce false colors and improve a sense of resolution. After a signal processing section carries out pixel mixing, the signal processing section carries out LPF processing on G pixels so as to correspond to an interval and a phase-of R pixels or B pixels, and determines correlation values of the G pixels, which have been subjected to the LPF processing, and the R pixels and the B pixels. After interpolation processing of the G pixels is carried out, the R pixels and the B pixels are interpolated on the basis of the G pixels and the correlation values.
1 . An image pickup device comprising:
a solid state image pickup element in which pixels of red color and blue color are disposed alternately in even-numbered rows and only pixels of green color are disposed in odd-numbered rows, or in which pixels of red color and blue color are disposed alternately in odd-numbered rows and only pixels of green color are disposed in even-numbered rows, the plurality of pixels being disposed in a state in which a square grid is rotated by substantially 45°;
a pixel mixing component mixing together each predetermined number of signals of same-colored pixels read-out from the solid state image pickup element, and generating a pixel signal for each of red color, green color and blue color;
a filter carrying out filter processing on the pixel signal of green color generated by the pixel mixing component, so as to correspond to a mixing interval of the pixel signal of red color or blue color generated by the pixel mixing component;
a correlation value computing component computing a correlation value of the pixel signal of red color or blue color generated by the pixel mixing component, and the pixel signal of green color which has been subjected to the filter processing; and
an interpolating component generating interpolation signals of red color or blue color, on the basis of the pixel signal of green color generated by the pixel mixing component, and the correlation value computed by the correlation value computing component.
2 . The image pickup device of claim 1 , wherein the interpolating component
generates interpolation signals of green color on the basis of the pixel signal of green color generated by the pixel mixing component, and
on the basis of the interpolation signals of green color and the correlation value, generates interpolation signals of red color or blue color of a same spatial frequency as a spatial frequency of the interpolations signal of green color.
3 . The image pickup device of claim 1 , wherein the filter carries out the filter processing on the pixel signal of green color, so as to correspond to a phase of the pixel signal of red color or blue color.
4 . The image pickup device of claim 1 , wherein the filter is a low-pass filter.
5 . The image pickup device of claim 1 , wherein the correlation value is a difference between the pixel signal of red color or blue color generated by the pixel mixing component, and the pixel signal of green color which has been subjected to the filter processing.
6 . A signal processing method comprising:
mixing together each predetermined number of signals of same-colored pixels from a solid state image pickup element in which pixels of red color and blue color are disposed alternately in even-numbered rows and only pixels of green color are disposed in odd-numbered rows, or in which pixels of red color and blue color are disposed alternately in odd-numbered rows and only pixels of green color are disposed in even-numbered rows, and in which the plurality of pixels are disposed in a state in which a square grid is rotated by substantially 45°, and generating a pixel signal for each of red color, green color and blue color;
carrying out filter processing on the pixel signal of green color, so as to correspond to a mixing interval of the generated pixel signal of red color or blue color;
computing a correlation value of the generated pixel signal of red color or blue color, and the pixel signal of green color which has been subjected to the filter processing; and
generating interpolation signals of red color or blue color, on the basis of the generated pixel signal of green color and the computed correlation value.
7 . The signal processing method of claim 6 , wherein
interpolation signals of green color are generated on the basis of the generated pixel signal of green color, and
interpolation signals of red color or blue color of a same spatial frequency as a spatial frequency of the interpolation signals of green color are generated on the basis of the interpolation signals of green color and the correlation value.
8 . The signal processing method of claim 6 , wherein the filter processing is carried out on the pixel signal of green color, so as to correspond to a phase of the pixel signal of red color or blue color.
9 . The signal processing method of claim 6 , wherein the filter processing allows the pixel signal to pass through a low frequency.
10 . The signal processing method of claim 6 , wherein the correlation value is a difference between the generated pixel signal of red color or blue color, and the pixel signal of green color which has been subjected to the filter processing.