Imaging device

1. An imaging device comprising: an imaging signal generation unit configured to capture images and generate an imaging signal indicating a pixel value for each pixel in a plurality of pixels constituting a sequence of temporally consecutive frames; an intra-plane pixel summation processor that: receives the imaging signal generated by the imaging signal generation unit, sequentially specifies the pixels in each of the consecutive frames, selects, for each specified pixel, an area consisting of pixels with high mutual correlation, from among a plurality of areas having predetermined relative positions or orientations with respect to the specified pixel, sums the pixel values of the pixels in the selected area, outputs a resulting sum as an intra-plane sensitized signal of the specified pixel, and outputs a pixel summing pattern code indicating the relative position or orientation of the selected area; and an inter-plane pixel summation processor that: sequentially specifies the consecutive frames as a frame of interest, sequentially specifies the pixels in the frame of interest as a pixel of interest, selects, for each pixel of interest, a pixel from each of one or more frames neighboring the frame of interest, on a basis of correlations of the intra-plane sensitized signal of the pixel of interest with the intra-plane sensitized signals of a pixel positioned identically to the pixel of interest and pixels in a neighborhood of the identically positioned pixel, results of comparisons of the correlations with a correlation decision threshold value, and the relative position or orientation of each of the selected areas with respect to the specified pixel, adds the intra-plane sensitized signals of the selected pixels in the one or more frames neighboring the frame of interest to the intra-plane sensitized signal of the pixel of interest, and outputs a resulting sum as a three-dimensionally sensitized signal.

2. The imaging device of claim 1 , wherein each of the plurality of areas has one of a set of predetermined shapes; the inter-plane pixel summation processer selects pixels not only on a basis of the relative position or orientation of the selected area with respect to the specified pixel but also on a basis of the shape of the selected area.

3. The imaging device of claim 1 , wherein the neighboring frames include at least one of a frame one frame period ahead of the frame of interest and a frame one frame period behind the frame of interest.

4. The imaging device of claim 1 , wherein the neighboring frames include: a frame one frame period ahead of the frame of interest; a frame two frame periods ahead of the frame of interest; a frame one frame period behind the frame of interest; and a frame two frame periods behind the frame of interest.

5. The imaging device of claim 1 , wherein at least one of the summing of the pixel values by the intra-plane pixel summation processor and the summing of the intra-plane sensitized signals by the inter-plane pixel summation processor is performed by weighted summation, using weighting coefficients determined on a basis of a sensitivity multiplier, the imaging device further comprising: an illuminance information generator that generates illuminance information indicating subject illuminance; and a controller that determines the sensitivity multiplier on a basis of the illuminance information.

6. The imaging device of claim 1 , wherein, if, among the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame, there is a pixel determined to be correlated with the pixel of interest from the results of the comparisons with the correlation decision threshold value and there is a pixel having the same pixel summing pattern code as the pixel of interest, then from among the pixels having the same pixel summing pattern code, the inter-plane pixel summation processor selects a pixel having the highest correlation with the intra-plane sensitized signal of the pixel of interest; and if, among the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame, no pixel is determined to be correlated with the pixel of interest from the results of the comparisons with the correlation decision threshold value or no pixel has the same pixel summing pattern code as the pixel of interest, then from among the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel, the inter-plane pixel summation processor selects a pixel having the highest correlation with the intra-plane sensitized signal of the pixel of interest.

7. The imaging device of claim 6 , wherein the intra-plane pixel summation processor further comprises a pixel extractor that delays the imaging signal generated by the imaging signal generation unit by different times to simultaneously extract signals indicating the pixel values of the specified pixel and the pixels in the neighborhood of the specified pixel, and the area selector combines, with respect to the specified pixel, pixels positioned in each of the plurality of areas among the pixels having the pixel values represented by the signals extracted by the pixel extractor, thereby forming pixel combinations constituting the respective areas, and from among the plurality of areas, selects an area with a minimum difference between minimum and maximum pixel values as the area consisting of pixels with high mutual correlation.

8. The imaging device of claim 6 , wherein the inter-plane pixel summation processor further comprises: a pattern code extractor that delays the pixel summing pattern code output from the intra-plane pixel summation processor by mutually different times to simultaneously extract the pixel summing pattern code of the pixel of interest and the pixel summing pattern codes of the pixels positioned identically to the pixel of interest and pixels in the neighborhoods of the identically positioned pixels in the neighboring frames, and a pattern discriminator that determines whether or not the pixel summing pattern code of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame are identical to the pixel summing pattern code of the pixel of interest.

9. The imaging device of claim 6 , wherein the intra-plane pixel summation processor comprises a signal combiner that combines the intra-plane sensitized signal of the specified pixel and the pixel summing pattern code of the specified pixel, thereby generating a composite signal of the specified pixel, and output the generated composite signal; and the inter-plane pixel summation processor comprises: a pixel extractor that delays the composite signal output from the signal combiner of the intra-plane pixel summation processor by different times to simultaneously extract the composite signal of the pixel of interest and the composite signals of the pixels positioned identically to the pixel of interest and the pixels in the neighborhoods of the identically positioned pixels in the neighboring frames, a pattern discriminator that determines whether or not the pixel summing pattern codes included in the composite signals of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame are identical to the pixel summing pattern code included in the composite signal of the pixel of interest, and a correlation discriminator that selects one of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame, on a basis of results of comparisons of differences between the intra-plane sensitized signals included in the composite signal of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame and the intra-plane sensitized signal included in the composite signal of the pixel of interest with the correlation decision threshold value and results of determinations made by the pattern discriminator.

10. The imaging device of claim 1 , wherein the intra-plane pixel summation processor comprises: an area selector that selects, for each specified pixel, the area consisting of pixels with high mutual correlation and output the pixel summing pattern code indicating the relative position or orientation of the selected area; and a selective summation processor that outputs the resulting sum obtained by summing the pixel values of the pixels included in the area selected by the area selector as the intra-plane sensitized signal of the specified pixel; and wherein the inter-plane pixel summation processor selects one pixel in an adjacent frame adjacent to the frame of interest, among the frames neighboring the frame of interest, on a basis of results of comparisons of differences between the intra-plane sensitized signal of the pixel positioned identically to the pixel of interest and pixels in the neighborhood of the identically positioned pixel in the adjacent frame with the correlation decision threshold value, and results of comparisons of the pixel summing pattern code of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame with the pixel summing pattern code of the pixel of interest.

11. The imaging device of claim 10 , wherein the intra-plane pixel summation processor further comprises a signal combiner configured to combine the intra-plane sensitized signal of the specified pixel and the pixel summing pattern code of the specified pixel, thereby generating a composite signal of the specified pixel, and output the generated composite signal; and the inter-plane pixel summation processor comprises: a pixel extractor that delays the composite signal output from the signal combiner of the intra-plane pixel summation processor by different times to simultaneously extract the composite signal of the pixel of interest and the composite signals of the pixels positioned identically to the pixel of interest and the pixels in the neighborhoods of the identically positioned pixels in the neighboring frames, a pattern discriminator that determines whether or not the pixel summing pattern codes included in the composite signals of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame are identical to the pixel summing pattern code included in the composite signal of the pixel of interest, and a correlation discriminator that selects one of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame, on a basis of results of comparisons of differences between the intra-plane sensitized signals included in the composite signal of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame and the intra-plane sensitized signal included in the composite signal of the pixel of interest with the correlation decision threshold value and results of determinations made by the pattern discriminator.

12. The imaging device of claim 10 , wherein, if, among the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame, there is a pixel determined to be correlated with the pixel of interest from the results of the comparisons with the correlation decision threshold value and there is a pixel having the same pixel summing pattern code as the pixel of interest, then from among the pixels having the same pixel summing pattern code, the inter-plane pixel summation processor selects a pixel having the highest correlation with the intra-plane sensitized signal of the pixel of interest; and if, among the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame, no pixel is determined to be correlated with the pixel of interest from the results of the comparisons with the correlation decision threshold value or no pixel has the same pixel summing pattern code as the pixel of interest, then from among the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel, the inter-plane pixel summation processor selects a pixel having the highest correlation with the intra-plane sensitized signal of the pixel of interest.

13. The imaging device of claim 12 , wherein the intra-plane pixel summation processor further comprises a pixel extractor that delays the imaging signal generated by the imaging signal generation unit by different times to simultaneously extract signals indicating the pixel values of the specified pixel and the pixels in the neighborhood of the specified pixel, and the area selector combines, with respect to the specified pixel, pixels positioned in each of the plurality of areas among the pixels having the pixel values represented by the signals extracted by the pixel extractor, thereby forming pixel combinations constituting the respective areas, and from among the plurality of areas, selects an area with a minimum difference between minimum and maximum pixel values as the area consisting of pixels with high mutual correlation.

14. The imaging device of claim 10 , wherein the inter-plane pixel summation processor further comprises: a pattern code extractor that delays the pixel summing pattern code output from the intra-plane pixel summation processor by mutually different times to simultaneously extract the pixel summing pattern code of the pixel of interest and the pixel summing pattern codes of the pixels positioned identically to the pixel of interest and pixels in the neighborhoods of the identically positioned pixels in the neighboring frames, and a pattern discriminator that determines whether or not the pixel summing pattern code of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame are identical to the pixel summing pattern code of the pixel of interest.

15. The imaging device of claim 14 , wherein the inter-plane pixel summation processor comprises: an intra-plane sensitized signal extractor that delays the intra-plane sensitized signal output from the intra-plane pixel summation unit by different times to simultaneously extract the intra-plane sensitized signal of the pixel of interest and the intra-plane sensitized signals of the pixels positioned identically to the pixel of interest and pixels in the neighborhood of the identically positioned pixel in the neighboring frames, and a correlation discriminator that selects one of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame, on a basis of results of comparisons of differences between the intra-plane sensitized signal of the pixel positioned identically to the pixel of interest and pixels in the neighborhood of the identically positioned pixel in the adjacent frame and the intra-plane sensitized signal of the pixel of interest with the correlation decision threshold value.

16. The imaging device of claim 15 , wherein the neighboring frames include not only the adjacent frame adjacent to the frame of interest but also a distant frame two or more frames distant from the frame of interest; and the pattern discriminator determines whether or not the pixel summing pattern code of a pixel in the distant frame matches the pixel summing pattern code of the pixel selected in a frame adjacent to the distant frame and located between the distant frame and the frame of interest, and the correction discriminator selects one of the pixel positioned identically to the pixel of interest and pixels in the neighborhood of the identically positioned pixel in the distant frame, on a basis of a result of comparisons of differences between the intra-plane sensitized signal of the pixels in the distant frame and the intra-plane sensitized signal of the pixel selected in the frame adjacent to the distant frame and located between the distant frame and the frame of interest with the correlation decision threshold value and a result of the determination as to whether or not the pixel summing pattern codes of the pixels in the distant frame match the pixel summing pattern code of the pixel selected in the frame adjacent to the distant frame and located between the distant frame and the frame of interest.

17. The imaging device of claim 10 , wherein the intra-plane pixel summation processor further comprises: a pixel extractor that delays the imaging signal generated by the imaging signal generation unit by different times to simultaneously extract signals indicating the pixel values of the specified pixel and the pixels in the neighborhood of the specified pixel, and the area selector combines, with respect to the specified pixel, pixels positioned in each of the plurality of areas among the pixels having the pixel values represented by the signals extracted by the pixel extractor, thereby forming pixel combinations constituting the respective areas, and from among the plurality of areas, selects an area with a minimum difference between minimum and maximum pixel values as the area consisting of pixels with high mutual correlation.

18. The imaging device of claim 17 , wherein the intra-plane pixel summation processor further comprises a signal combiner that combines the intra-plane sensitized signal of the specified pixel and the pixel summing pattern code of the specified pixel, thereby generating a composite signal of the specified pixel, and output the generated composite signal; and the inter-plane pixel summation processor comprises: a pixel extractor that delays the composite signal output from the signal combiner of the intra-plane pixel summation processor by different times to simultaneously extract the composite signal of the pixel of interest and the composite signals of the pixels positioned identically to the pixel of interest and the pixels in the neighborhoods of the identically positioned pixels in the neighboring frames, a pattern discriminator that determines whether or not the pixel summing pattern codes included in the composite signals of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame are identical to the pixel summing pattern code included in the composite signal of the pixel of interest, and a correlation discriminator that selects one of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame, on a basis of results of comparisons of differences between the intra-plane sensitized signals included in the composite signal of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame and the intra-plane sensitized signal included in the composite signal of the pixel of interest with the correlation decision threshold value and results of determinations made by the pattern discriminator.

19. The imaging device of claim 17 , wherein the inter-plane pixel summation processor further comprises: a pattern code extractor that delays the pixel summing pattern code output from the intra-plane pixel summation processor by mutually different times to simultaneously extract the pixel summing pattern code of the pixel of interest and the pixel summing pattern codes of the pixels positioned identically to the pixel of interest and pixels in the neighborhoods of the identically positioned pixels in the neighboring frames, and a pattern discriminator that determines whether or not the pixel summing pattern code of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the neighboring frames, and a pattern discriminator that determines whether or not the pixel summing pattern code of the pixel positioned identically to the pixel of interest and the pixels in the neighborhood of the identically positioned pixel in the adjacent frame are identical to the pixel summing pattern code of the pixel of interest.

20. The imaging device of claim 19 , wherein the neighboring frames include not only the adjacent frame adjacent to the frame of interest but also a distant frame two or more frames distant from the frame of interest; and the pattern discriminator determines whether or not the pixel summing pattern code of a pixel in the distant frame matches the pixel summing pattern code of the pixel selected in a frame adjacent to the distant frame and located between the distant frame and the frame of interest, and the correction discriminator selects one of the pixel positioned identically to the pixel of interest and pixels in the neighborhood of the identically positioned pixel in the distant frame, on a basis of a result of comparisons of differences between the intra-plane sensitized signal of the pixels in the distant frame and the intra-plane sensitized signal of the pixel selected in the frame adjacent to the distant frame and located between the distant frame and the frame of interest with the correlation decision threshold value and a result of the determination as to whether or not the pixel summing pattern codes of the pixels in the distant frame match the pixel summing pattern code of the pixel selected in the frame adjacent to the distant frame and located between the distant frame and the frame of interest.