An image reading apparatus includes: a light source; a reference sheet that reflects light emitted from the light source; a light-receiving lens that converges the reflected light; a reading sensor that reads the light converged by the light-receiving lens; and a hardware processor that: based on first white data obtained when the reading sensor reads the reference sheet for the first time, determines whether the reference sheet or the reading sensor has dust; in response to determining that the reference sheet or the reading sensor has dust, produces ideal initial white reference data by complementing the first white data with second white data obtained when the reading sensor reads the reference sheet for the second and subsequent times; and with the ideal initial white reference data, complements third white data obtained when the reading sensor reads the reference sheet right before reading an image of a job.

A mat for an image pickup apparatus, where the image pickup apparatus operates to recognize a real object, the mat includes: a play field that defines a bottom region of a space in which the real object is placed; and a calibration chart located in the space and having a plurality of color regions in which respective luminances thereof differ from one another, where: the image pickup apparatus: (i) obtains data of a picked up image of the space in which the real object is located; and (ii) evaluates the picked up image and adjusts at least one of an image pickup condition in which the picked up image of the space is taken, and a processing condition in which the data are analyzed to recognize the real object, and at least one of the image pickup condition and the processing condition are adjusted based on color information in the data of the picked up image resulting from the plurality of color regions of the calibration chart.

An image scanning apparatus determines whether there is an influence of external light from the outside of the image scanning apparatus on scanning; decides a correction value corresponding to each of a plurality of sensors based on received light amounts of at least some of the plurality of sensors; and corrects, using the correction value corresponding to each of the plurality of sensors and decided, data corresponding to a received light amount of each of the plurality of sensors when scanning the original, wherein if it is determined that there is the influence of the external light, the image scanning apparatus decides the correction value corresponding to a first sensor and the correction value corresponding to a second sensor arranged at a position that is readily influenced by the external light based on the received light amount of the first sensor.

The inventive plastic card permits a scuba diver to photograph underwater such as at 100 feet, without using external lighting, and to achieve quality photographic images as if external lighting actually had been used during the underwater photography.

An image reading apparatus including a controller configured to perform an update processing for updating shading correction data stored in a memory by a generation processing of generating shading correction data based on an image signal of a reference member and perform a size determination processing for determining a size of a document based on an image signal of the document, wherein, when the document on the document platen is read, the controller performs the generation processing before the document is read, and an image processing portion performs the shading correction using the shading correction data generated before the document is read, and wherein, when the size determination processing is performed, the image processing portion performs the shading correction using the shading correction data stored in the memory, and the update processing is not performed.

A photoelectric conversion device includes a photoelectric conversion element to generate an image signal according to an intensity of light being input and circuitry. The circuitry obtains pixel values in dark time, respectively, for at least a first time and a second time. The second time is longer than the first time. The pixel values in dark time represent pixel values obtained when no light is input to the photoelectric conversion element. The circuitry obtains a subtraction between the pixel values for the first time and the pixel values for the second time. The circuitry detects a noise amount based on the subtraction. The circuitry determines at least one pixel having the detected noise amount that is equal to or greater than a predetermined first threshold value, as a defective pixel of the photoelectric conversion element.

A shading correction device includes a reference acquirer that acquires a reference pixel value W in a captured image of a color measurement reference object, a target pixel value acquirer that acquires a pixel value S in a captured image of a measurement target, a bit shift value acquirer that acquires a bit shift value k2 based on the reference pixel value W, a lookup table storing a variable G.sub.2 (=2.sup.k1/W>>k2) corresponding to W>>k2, and a calculator that reads the variable G.sub.2 corresponding to the reference pixel value W and the bit shift value k2 from the lookup table and calculates a shading correction value R.sub.dec of each pixel in the captured image of the measurement target using Expression (5): $\begin{array}{c}{R}_{\mathrm{dec}}=\left(F.Math.G_2\right)\left(k1+k2\right)+B\mathrm{where}F=S.Math.\left(A-B\right)\end{array}$

The present invention provides an image processing device and an image processing method capable of removing haze (reducing the effect of haze) without losing detail of a high-luminance subject. In the aspect of the present invention, the input image I is represented by I=J.Math.t+A.Math.(1t) where an original image is J, an atmospheric light pixel value is A, and a transmittance is t. In this case, a dark channel value D of each pixel of the input image I is calculated, and is associated with the transmittance t having a value monotonically decreasing for each pixel of which D ranges from 0 to 1 and associated with the transmittance t having a value monotonically increasing for each pixel which corresponds to haze and of which D ranges from 1 to Dmax. In such a manner, the original image J is generated as a corrected image.

A correction plate has the same plane size as a small region obtained by equally dividing an image detection region. In addition, the correction plates whose number is equal to the number of small regions are prepared. In a maintenance mode, a plurality of correction plates are laid in the image detection region such that the entire image detection region is covered with the plurality of correction plates. In this state, scanning is performed and a correction image signal obtained by detecting fluorescent light from the correction plate is output. An acquisition unit of a console acquires a correction image signal and a creation unit creates a correction image on the basis of the correction image signal. A correction unit performs shading correction on the basis of the correction image.

An image of a block or the like entering a space above a play mat is picked up by an image pickup apparatus, and an information processing apparatus detects and recognizes the block on the basis of a picture of the block in a picked up image and performs information processing. The play mat includes a play field that defines a detection space for the block, and a calibration chart including at least a plurality of regions of colors of different luminances. The image pickup apparatus adjusts an exposure time period, a gain value for each color component and a correction rule upon gamma correction on the basis of the picture of the calibration chart in the picked up image.