Imaging apparatus, signal processing method, and program
The present disclosure provides an apparatus and a method for generating a wide dynamic range image by executing a pixel value combination process of a plurality of different exposure time setting pixels. Control of a different exposure time is performed for each of a plurality of pixels of the same colors configuring a pixel block and an addition pixel value obtained by adding outputs of the plurality of pixels of the same colors of the pixel block is generated. The generation of the addition pixel value is executed in an operation unit having an adding unit that that adds the outputs of the plurality of pixels of the same colors of the pixel block. Or, the generation of the addition pixel value is executed by a floating diffusion (FD) set in a pixel block unit and a charge output from each of the plurality of pixels of the same colors configuring the pixel block is accumulated and output in the floating diffusion (FD).
1. An imaging device comprising:
a two-dimensional pixel array including a plurality of pixel blocks each of which includes four pixels of a same color, wherein the four pixels are arranged in a 2×2 matrix and share a floating diffusion, wherein the four pixels comprise first, second, third, and fourth pixels, and wherein the first pixel and the fourth pixel are arranged on a diagonal direction and the second pixel and the third pixel are arranged on an opposed diagonal direction; and
a controller configured to provide control signals for a different exposure time for each of the four pixels of a pixel block, wherein the shared floating diffusion is configured to perform an addition process by adding charge accumulated for the different exposure times within each of the four pixels of the pixel block, and further wherein control signals for a longest exposure time and for a third-longest exposure time from among the different exposure times are provided for two respective pixels of the pixel block on a same side of the 2×2 matrix, and wherein respective lengths of the different exposure times are set from longest to shortest for the first pixel, the fourth pixel, the third pixel, and the second pixel, in order.
2. The imaging device according to claim 1 , further comprising;
an output circuitry configured to output an addition pixel value generated the addition process performed in the shared floating diffusion.
3. The imaging apparatus according to claim 1 , further comprising adding circuitry including a register configured to store values of a plurality of pixels set to a precedent read row of the pixel block and an adding unit that adds read pixel values of a plurality of pixels set to a following read row of the pixel block and the pixel values stored in the register.
4. The imaging device according to claim 1 , wherein the different exposure times overlap.
5. The imaging device according to claim 1 , wherein the different exposure times are synchronized to end at substantially a same time.
6. A signal processing method that is executed in an imaging apparatus including a two-dimensional pixel array including a plurality of pixel blocks, each of which includes four pixels of a same color, wherein the four pixels are arranged in a 2×2 matrix and share a floating diffusion, wherein the four pixels comprise first, second, third, and fourth pixels, and wherein the first pixel and the fourth pixel are arranged on a diagonal direction and the second pixel and the third pixel are arranged on an opposed diagonal direction, the method comprising:
performing control of a different exposure time for each of the four pixels of a pixel block, wherein control signals for a longest exposure time and for a third-longest exposure time from among the different exposure times are provided for two respective pixels of the pixel block on a same side of the 2×2 matrix, and wherein respective lengths of the different exposure times are set from longest to shortest for the first pixel, the fourth pixel, the third pixel, and the second pixel, in order; and
adding charge accumulated for the different exposure times within each of the four pixels in the shared floating diffusion.
7. The signal processing method of claim 6 , further comprising outputting an addition pixel value corresponding to the added charge accumulated in the shared floating diffusion.
8. The signal processing method of claim 6 , further comprising:
storing in a register, values of a plurality of pixels set to a precedent read row of the pixel block; and
adding read pixel values of a plurality of pixels set to a following read row of the pixel block and the pixel values stored in the register.
9. The signal processing method of claim 6 , wherein the different exposure times overlap.
10. The signal processing method of claim 6 , wherein performing control of a different exposure time for each of the four pixels of a pixel block comprises synchronizing the different exposure times to end at substantially a same time.
11. A non-transitory recording medium encoded with a plurality of processor-executable instructions that, when executed by at least one processor, cause a signal process to be executed in an imaging apparatus including a two-dimensional pixel array including a plurality of pixel blocks, each of which includes four pixels of a same color, wherein the four pixels are arranged in a 2×2 matrix and share a floating diffusion, wherein the four pixels comprise first, second, third, and fourth pixels, and wherein the first pixel and the fourth pixel are arranged on a diagonal direction and the second pixel and the third pixel are arranged on an opposed diagonal direction, the signal process comprising:
performing control of a different exposure time for each of the four pixels of a pixel block, wherein control signals for a longest exposure time and for a third-longest exposure time from among the different exposure times are provided for two respective pixels of the pixel block on a same side of the 2×2 matrix, and wherein respective lengths of the different exposure times are set from longest to shortest for the first pixel, the fourth pixel, the third pixel, and the second pixel, in order; and
adding charge accumulated for the different exposure times within each of the four pixels in the shared floating diffusion.