Three-dimensional imaging device

1. A 3D image capture device comprising:

a light-transmitting plate with first, second and third transmitting areas that have mutually different transmission wavelength ranges, the first and second transmitting areas being surrounded by the third transmitting area, the first transmitting area being made of a member that transmits a light ray falling within one of the cyan, yellow and magenta wavelength ranges, the second transmitting area being made of a member that transmits a light ray falling within another one of the cyan, yellow and magenta wavelength ranges, the third transmitting area being made of a transparent member or a member that transmits a light ray falling within a red, green or blue wavelength range, the third transmitting area being larger than the first and second transmitting areas;

a solid-state image sensor that includes a photosensitive cell array and that is arranged so as to receive the light that has been transmitted through the light-transmitting plate, the photosensitive cell array being made up of a number of unit blocks, each said unit block including R, G and B sensing cells that respectively output first, second and third photoelectrically converted signals representing the quantities of light falling within red, green and blue wavelength ranges, respectively;

an optical system that produces an image on an imaging area of the solid-state image sensor based on the light that has been transmitted through the light transmitting plate; and

a signal processor that processes the output signal of the solid-state image sensor, wherein the signal processor performs processing, including addition and subtraction, on the first, second and third photoelectrically converted signals, thereby generates cyan, yellow and magenta color image signals with parallax, and estimates the parallax between the cyan, yellow and magenta images,

wherein the first photoelectrically converted signal is identified by Rs, the second photoelectrically converted signal is identified by Gs, and the third photoelectrically converted signal is identified by Bs, the signal processor:

generates the cyan color image signal by performing processing including a calculation of (Gs+Bs−Rs);

generates the Yellow color image signal by performing processing including a calculation of (Rs+Gs−Bs); and

generates the Magenta color image signal by performing processing including a calculation of (Rs+Bs−Gs);

wherein the light-transmitting plate includes a fourth transmitting area surrounded by the third transmitting area, and the fourth transmitting area is made of a member that transmits a light ray falling within the other one of the cyan, yellow and magenta wavelength ranges.

2. The 3D image capture device of claim 1 , wherein the signal processor generates information about a distance to a subject based on the parallax that has been estimated.

3. The 3D image capture device of claim 1 , wherein the signal processor:

selects an estimate of the magnitude of parallax from among multiple candidates with respect to each pixel of the cyan, yellow and magenta color images and that extracts, based on the estimate, three pixel blocks of the same size, of which the on-image positions have shifted from each other, from the cyan, yellow and magenta color images;

determines how much the distribution of a set of points on a three-dimensional color space, which is defined by the sets of pixel values of the three pixel blocks, has shifted from a line; and

defines the estimate, of which the degree of shift from the line that has been determined turns out to be the minimum, to be the magnitude of parallax at each said pixel.

4. A signal processing method for processing the output signal of an image capture device, the device comprising:

a light-transmitting plate with first, second and third transmitting areas that have mutually different transmission wavelength ranges, the first and second transmitting areas being surrounded by the third transmitting area, the first transmitting area being made of a member that transmits a light ray falling within one of the cyan, yellow and magenta wavelength ranges, the second transmitting area being made of a member that transmits a light ray falling within another one of the cyan, yellow and magenta wavelength ranges, the third transmitting area being made of a transparent member or a member that transmits a light ray falling within a red, green or blue wavelength range, the third transmitting area being larger than the first and second transmitting areas;

a solid-state image sensor that includes a photosensitive cell array and that is arranged so as to receive the light that has been transmitted through the light-transmitting plate, the photosensitive cell array being made up of a number of unit blocks, each said unit block including R, G and B sensing cells that respectively output first, second and third photoelectrically converted signals representing the quantities of light falling within red, green and blue wavelength ranges, respectively; and

an optical system that produces an image on an imaging area of the solid-state image sensor based on the light that has been transmitted through the light transmitting plate,

the signal processing method comprising:

performing processing, including addition and subtraction, on the first, second and third photoelectrically converted signals, thereby generating cyan, yellow and magenta color image signals with parallax; and

estimating the parallax between the cyan, yellow and magenta images,

wherein the first photoelectrically converted signal is identified by Rs, the second photoelectrically converted signal is identified by Gs, and the third photoelectrically converted signal is identified by Bs, the generating comprising:

generating the cyan color image signal by performing processing including a calculation of (Gs+Bs−Rs);

generating the Yellow color image signal by performing processing including a calculation of (Rs+Gs−Bs); and

generating the Magenta color image signal by performing processing including a calculation of (Rs+Bs−Gs);

wherein the light-transmitting plate includes a fourth transmitting area surrounded by the third transmitting area, and the fourth transmitting area is made of a member that transmits a light ray falling within the other one of the cyan, yellow and magenta wavelength ranges.

5. The signal processing method of claim 4 , further comprising generating information about a distance to a subject based on the parallax that has been estimated.

6. The signal processing method of claim 4 , wherein the estimating includes:

selecting an estimate of the magnitude of parallax from among multiple candidates with respect to each pixel of the cyan, yellow and magenta color images and extracting, based on the estimate, three pixel blocks of the same size, of which the on-image positions have shifted from each other, from the cyan, yellow and magenta color images;

determining how much the distribution of a set of points on a three-dimensional color space, which is defined by the sets of pixel values of the three pixel blocks, has shifted from a line; and

defining the estimate, of which the degree of shift from the line that has been determined turns out to be the minimum, to be the magnitude of parallax at each said pixel.