A method for color correction in a camera system having a camera, a light source and a controller, the method comprising: setting a first light source drive current level; performing a first white balance operation and obtaining at least one of red gain, blue gain and green gain values corresponding to the first light source drive current level; setting a second light source drive current level different than the first light source drive current level; performing a second white balance operation and obtaining at least one of red gain, blue gain and green gain values corresponding to the second light source drive current level; and determining a relationship between light source current levels and at least one of red gain, blue gain and green gain values using the obtained at least one of red gain, blue gain and green gain values corresponding to the first and second light source drive current levels.

An image pickup apparatus is capable of executing automatic focus detection of an imaging optical system, and includes a first acquisition unit configured to acquire aberration information of the imaging optical system, a second acquisition unit configured to acquire object information of an object in a focus detecting area, a calculation unit configured to calculate, based on the aberration information of the imaging optical system and the object information, a correction value used to correct a difference between a focus state of a captured image and a result of the automatic focus detection, caused by the aberration of the imaging optical system, and a correction unit configured to correct the result of the automatic focus detection using the correction value.

An image pickup apparatus is capable of executing automatic focus detection of an imaging optical system, and includes a first acquisition unit configured to acquire aberration information of the imaging optical system, a second acquisition unit configured to acquire object information of an object in a focus detecting area, a calculation unit configured to calculate, based on the aberration information of the imaging optical system and the object information, a correction value used to correct a difference between a focus state of a captured image and a result of the automatic focus detection, caused by the aberration of the imaging optical system, and a correction unit configured to correct the result of the automatic focus detection using the correction value.

An image sensor may have an array of image sensor pixels arranged in color filter unit cells each having one red image pixel that generates red image signals, one blue image pixel that generate blue image signals, and two clear image sensor pixels that generate white image signals. The image sensor may be coupled to processing circuitry that performs filtering operations on the red, blue, and white image signals to increase noise correlations in the image signals that reduce noise amplification when applying a color correction matrix to the image signals. The processing circuitry may extract a green image signal from the white image signal. The processing circuitry may compute a scaling value that includes a linear combination of the red, blue, white and green image signals. The scaling value may be applied to the red, blue, and green image signals to produce corrected image signals having improved image quality.

An image sensor may have an array of image sensor pixels arranged in color filter unit cells each having one red image pixel that generates red image signals, one blue image pixel that generate blue image signals, and two clear image sensor pixels that generate white image signals. The image sensor may be coupled to processing circuitry that performs filtering operations on the red, blue, and white image signals to increase noise correlations in the image signals that reduce noise amplification when applying a color correction matrix to the image signals. The processing circuitry may extract a green image signal from the white image signal. The processing circuitry may compute a scaling value that includes a linear combination of the red, blue, white and green image signals. The scaling value may be applied to the red, blue, and green image signals to produce corrected image signals having improved image quality.

An image sensor may have an array of image sensor pixels arranged in color filter unit cells each having one red image pixel that generates red image signals, one blue image pixel that generate blue image signals, and two clear image sensor pixels that generate white image signals. The image sensor may be coupled to processing circuitry that performs filtering operations on the red, blue, and white image signals to increase noise correlations in the image signals that reduce noise amplification when applying a color correction matrix to the image signals. The processing circuitry may extract a green image signal from the white image signal. The processing circuitry may compute a scaling value that includes a linear combination of the red, blue, white and green image signals. The scaling value may be applied to the red, blue, and green image signals to produce corrected image signals having improved image quality.

Disclosed is an image quality improving apparatus, a digital photography apparatus having same, and a method for improving image quality, the image quality improving apparatus comprising: a zone-collected reduction filter (ZRF) which is disposed between a lens unit and an image sensor to let light which has penetrated the lens unit to penetrate and be irradiated on the image sensor, and by means of which the light penetration rate for every multiply partitioned area is controlled; an image processing unit for processing an image acquired by the image sensor into data; and a ZRT control unit for calculating the brightness of plurality of areas, into which the image has been partitioned, by means of the data processed by the image processing unit, and controlling the light penetration rate in the ZRF areas so as to reduce the brightness differential between the areas in the image.

An image sensor may have an array of image sensor pixels arranged in color filter unit cells each having one red image pixel that generates red image signals, one blue image pixel that generate blue image signals, and two clear image sensor pixels that generate white image signals. The image sensor may be coupled to processing circuitry that performs filtering operations on the red, blue, and white image signals to increase noise correlations in the image signals that reduce noise amplification when applying a color correction matrix to the image signals. The processing circuitry may extract a green image signal from the white image signal. The processing circuitry may compute a scaling value that includes a linear combination of the red, blue, white and green image signals. The scaling value may be applied to the red, blue, and green image signals to produce corrected image signals having improved image quality.