Color signal processing circuit, method of the same and a camera apparatus

A color signal processing circuit comprising:

• an input for supplying a color signal formed of red, green and blue color signals that are color-separated from an image signal produced by a solid-state imaging device;
• an amplifier having respective gains for amplifying said red, green and blue color signals;
• a pull-in determining circuit for determining if the color signal, as projected onto a two-dimensional coordinate system, is positioned within a first pull-in region and within a second pull-in region, said first pull-in region containing said second pull-in region, and both said first and second pull-in regions containing the origin of said two-dimensional coordinate system which represents a white color, said pull-in determining circuit additionally determining the pull-in for said color signal to be white-balanced and processed as a white color;
• and
• a gain adjustment circuit for adjusting the respective gains of said amplifier so as to pull in the projected color signal toward said origin;
• wherein the two-dimensional coordinate system is defined by a (R+B−2G) axis, where R is the red color signal, B is the blue color signal and G is the green color signal, and a (R-B) axis.

A color signal processing method comprising the steps of:

• supplying a color signal formed of red, green and blue color signals that are color-separated from an image signal produced by a solid-state imaging device;
• amplifying said red, green and blue color signals with respective gains;
• determining first if the color signal, as projected onto a two-dimensional coordinate system, is positioned within a first pull-in region and if it is determined that said color signal is positioned within said pull-in region, then second determining if the color signal is positioned within a second pull-in region, said first pull-in region containing said second pull-in region, and both said first and second pull-in regions containing the origin of said two-dimensional coordinate system which represents a white color, and determining the pull-in for said color signal to be white-balanced and processed as a white color;
• and
• adjusting said respective gains so as to pull in the projected color signal toward said origin.

A color signal processing method, comprising the steps of:

• supplying a color signal formed of red, green and blue color signals that are color-separated from an image signal produced by a solid-state imaging device;
• amplifying said red, green and blue color signals with respective gains;
• determining if the color signal, as projected onto a two-dimensional coordinate system, is positioned within a first pull-in region and within a second pull-in region, said first pull-in region containing said second pull-in region, and both said first and second pull-in regions containing the origin of said two-dimensional coordinate system which represents a white color, and determining the pull-in for said color signal to be white-balanced and processed as a white color;
• and
• adjusting said respective gains so as to pull in the projected color signal toward said origin;
• wherein the two-dimensional coordinate system is defined by a (R+B−2G) axis, where R is the red color signal, B is the blue color signal and G is the green color signal, and a (R-B) axis.

Camera apparatus for comprising:

• imaging means including a plurality of solid-state imaging elements for generating an analog image signal of an object;
• an A/D converter for converting the analog image signal to a digital image signal;
• a color separation circuit for separating the digital image signal to a red color signal, a green color signal and a blue color signal;
• an amplifier having respective gains for amplifying said red, green and blue color signals;
• a pull-in determining circuit for first determining if all color signals, as projected onto a two-dimensional coordinate system, is positioned within a first pull-in region and if it is determined that said color signal is positioned within said first pull-in region, then second determining if the color signal is positioned within a second pull-in region, said first pull-in region containing said second pull-in region, and both said first and second pull-in regions containing the origin of said two-dimensional coordinate system which represents a white color, said pull-in determining circuit additionally determining the pull-in for said color signal to be white-balanced and processed as a white color;
• and
• a gain adjustment circuit for adjusting the respective gains of said amplifier so as to pull in the projected color signal toward said origin.

Camera apparatus comprising:

• imaging means including a plurality of solid-state imaging elements for generating an analog image signal of an object;
• an A/D converter for converting the analog image signal to a digital image signal;
• a color separation circuit for separating the digital image signal to a red color signal, a green color signal and a blue color signal;
• an amplifier having respective gains for amplifying said red, green and blue color signals;
• a pull-in determining circuit for determining if the color signal, as projected onto a two-dimensional coordinate system, is positioned within a first pull-in region and within a second pull-in region, said first pull-in region containing said second pull-in region, and both said first and second pull-in regions containing the origin of said two-dimensional coordinate system which represents a white color, said pull-in determining circuit additionally determining the pull-in for said color signal to be white-balanced and processed as a white color;
• and
• a gain adjustment circuit for adjusting the respective gains of said amplifier so as to pull in the projected color signal toward said origin;
• wherein the two-dimensional coordinate system is defined by a (R+B−2G) axis, where R is the red color signal, B is the blue color signal and G is the green color signal, and a (R-B) axis.