An image processing device performing color balancing of a first image and at least a second image is provided. The image processing device comprises a color balancing determination unit and a color balancing calculation unit. The color balancing determination unit determines a global gain vector (t) comprising at least two gain factors (.sup.n, .sup.n+1) of the first and second images by minimizing a cost function based upon reference pixel values of the first and second images. The first and second image reference pixels depict a shared color scene of the two images. The color balancing calculation unit performs color balancing of the first image based upon the gain factor (.sup.n) of the first image and to perform a color balancing of the second image based upon the gain factor (.sup.n+1) of the second image.

Provided are an image composition apparatus for composing color images with black-and-white images including infrared components, and an image composition method thereof. The image composition method includes generating a first image signal with color information and a second image signal including infrared components without color information, dividing the first image signal into a brightness signal and a color signal, composing the brightness signal of the first image signal with a brightness signal of the second image signal to generate a composed brightness signal, and composing the composed brightness signal with the color signal of the first image signal to generate a color image.

An image reading apparatus comprises a light source for repeatedly emitting first light having a first color, second light having a second color and third light having a third color toward a read target while moving the light source in a sub-scanning direction, first, second, and third sensors, each configured to sense a strength of first, second, and third reflected light, respectively, in a light reflected from the read target, and to output first, second, and third signal waveforms corresponding to the strength of the first, second, and third reflected light, respectively, and a controller. The controller is configured to execute a line-to-line correction for correcting a phase shift between the first, second, and third signal waveforms, and to correct a shift in a signal level caused by the line-to-line correction.

A combined imaging and spectral measurement line-scan imaging sensor includes a plurality of pixel lines. Each pixel line includes a plurality of pixels. At least one of the pixel lines is an imaging line designated for acquiring at least one image of an object and other of the pixel lines are spectral measurement lines designated for acquiring a spectral measurement of light received from the object. Each imaging line is associated with a single respective spectral response within a spectral range. Each pixel in each spectral measurement line is associated with a respective spectral band. Each of at least three pixels in each of the spectral measurement lines is respectively associated with different respective pixel spectral bands. The different respective pixel spectral bands are non-identical to any one of the single spectral responses associated with each of the imaging spectral lines.

An image reading device includes a light applying unit that applies light from a light source to a recording medium, a detecting unit that detects the light reflected by the recording medium, a holding member that is movable in a first scanning direction of the light applying unit and holds a calibration member to which the light from the light applying unit is applied, a shaft member that extends in the first scanning direction through the holding member and guides the movement of the holding member in the first scanning direction, and a restricting member that extends in the first scanning direction and restricts rotation of the holding member about the shaft member.

A document reading unit includes an R light source, a G light source, a B light source, a UV light source, a lighting control unit, a first photoelectric conversion element, a second photoelectric conversion element, a lens, and an output unit. The first photoelectric conversion element includes an M filter. The second photoelectric conversion element includes a G filter. The output unit outputs outputs of the first photoelectric conversion element and the second photoelectric conversion element at the time of simultaneous lighting of the R and G light sources and an output of the first photoelectric conversion element at the time of simultaneous lighting of the B and UV light sources as the image data, and outputs an output of the second photoelectric conversion element at the time of simultaneous lighting of the B and UV light source as fluorescent color data indicating a fluorescent color region.

A solid-state image sensor includes a first color filter and a second color filter having different thicknesses and configured to transmit light in predetermined wavelength regions, light-receiving devices configured to receive the light in the predetermined wavelength regions passing through the first color filter and the second color filter, and a light amount compensator configured to compensate for an amount of the light passing through the first color filter or the second color filter.

A method of balancing responses of a plurality of sensor chips arranged generally in a linear array comprising: exposing the plurality of sensor chips to an absence of illumination; measuring a dark response of each photosensor of a plurality of photosensors; positioning a calibration piece within a field of view of the plurality of sensor chips other than a calibration sensor chip; illuminating a calibration standard and the calibration piece with a light source; measuring a light response of each photosensor of the plurality of photosensors; applying an offset to the light response of each photosensor of the plurality of photosensors by subtracting the dark response of each photosensor of the plurality of photosensors to obtain an offset light response for each photosensor of the plurality of photosensors; calculating a mean offset light response for each sensor chip of the plurality of sensor chips by averaging the offset light response for each photosensor of the plurality of photosensors in each sensor chip of the plurality of sensor chips; calculating a modified light response for each photosensor of the plurality of photosensors by modifying the offset light response for each photosensor of the plurality of photosensors based on the mean offset light response of the sensor chip comprising the respective photosensor, the mean offset light response of the calibration sensor chip, an initial mean offset light response of the sensor chip comprising the respective photosensor, and an initial mean offset light response of the calibration sensor chip; and, applying a first gain to the offset light response of each photosensor of the plurality of photosensors based on the modified light response of each respective photosensor to obtain a corrected light response of each photosensor of the plurality of photosensors.

An image processing apparatus specifies, from among target pixels in a target image, first pixels related to a first color, and determines whether a specific condition is met for each peripheral pixel of the target pixel. The specific condition includes a condition that each peripheral pixel is a candidate for a pixel representing one of colors different from the first color. The apparatus specifies, as a second pixel related to a second color, each peripheral pixel meeting the specific condition. The apparatus performs an image process on target image data by using specified first and second pixels to generate processed image data. In a processed image, first processed pixels correspond to the specified first pixels and have the first color, and second processed pixels correspond to the specified second pixels and have the second color.

Provided are an image composition apparatus for composing color images with black-and-white images including infrared components, and an image composition method thereof. The image composition method includes generating a first image signal with color information and a second image signal including infrared components without color information, dividing the first image signal into a brightness signal and a color signal, composing the brightness signal of the first image signal with a brightness signal of the second image signal to generate a composed brightness signal, and composing the composed brightness signal with the color signal of the first image signal to generate a color image.