Imaging processing device and imaging processing method

An imaging processing method for use in operating an imaging processing device, the imaging processing device comprising:

• an imaging sensor in which a plurality light-receiving elements are arranged;
• a filter for transmitting at least a part of a visible light and at least a part of an infrared light, in which:
• i) a plurality of kinds of filter regions are arranged in a predetermined array corresponding to an arrangement of the plurality of light receiving elements of the imaging sensor;
• ii) respective kinds of filter regions have different transmission characteristics in response to wavelengths in a visible-light band;
• and iii) each kind of filter regions have an infrared-light transmission wavelength band for light transmitting on a longer wavelength side than the visible-light band, and a light-blocking wavelength band for light blocking between the visible-light band and the infrared-light transmission wavelength band;
• the method comprising:
• an imaging step in which a light signal inputted through the filter is converted into a sensor signal in the imaging sensor;
• and
• a signal processing step in which an infrared light component is removed from the sensor signal outputted in the imaging step, and a visible image output signal is outputted, wherein
• in the signal processing step, when the sensor signal reaches a pixel saturation level of the imaging sensor, a value of the visible image output signal corresponding to the sensor signal is reduced to a constant value lower than the pixel saturation level.

An imaging processing device comprising:

• an imaging sensor in which a plurality light-receiving elements are arranged;
• a color filter in which a plurality of kinds of filter regions having different spectral transmission characteristics in response to wavelengths in a visible light band are arranged in a predetermined array corresponding to an arrangement of light receiving elements in an imaging sensor main body;
• an optical filter that has a transmission characteristic in the visible-light band, and a blocking wavelength band for light blocking in a first wavelength band adjacent to the long wavelength side of the visible-light band, and a second wavelength band for light transmission in a part of the first wavelength region;
• and
• a signal processing device which removes an infrared light component from a sensor signal outputted from the imaging sensor and containing a visible light component and an infrared light component to output at least a visible image output signal,
• wherein
• the color filter has a third wavelength band in which transmittances of the filter regions of respective colors are approximate to one another on a longer wavelength side than the visible light band,
• a spectral transmission characteristic of the optical filter and a spectral transmission characteristic of each filter region of the color filter are set in a manner such that the second wavelength band is included in the third wavelength band, and
• the signal processing device is configured such that when the sensor signal reaches a pixel saturation level, the signal processing device operates to reduce the value of the visible image output signal corresponding to the sensor signal to a constant value lower than the pixel saturation level.