Abstract: An image processing device and method which is provided with means for converting image data from an image sensor into image data emphasizing a change in brightness in each of plural divisions of a whole luminous area by using a conversion table and which is therefore capable of easily and immediately enhancing the contrast of an image taken by an image sensor possessing a wide dynamic range of its logarithmic output characteristic.

Abstract: A method of determining a gamma curve of a display device includes identifying a region of interest of a display surface of the display device. A centroid of the region of interest is calculated. A plurality of input levels is applied to the display device to generate a corresponding plurality of displayed images on the display surface. At least one image of each of the displayed images is captured with a camera. A gamma curve of the display device is calculated based on the captured images and the centroid.

Abstract: An imaging apparatus can provide final image data with a good quality irrespective of overexposure or underexposure. The imaging apparatus includes an imaging unit capturing a subject image to produce image data, a conversion unit performing a gradation conversion on the image data, a modification unit determining the level of brightness of the image data before the gradation conversion, and modifying input/output characteristics for the gradation conversion on the image data when a brightness level of the image data is lower than a reference level of brightness. The input/output characteristics include a gamma characteristic portion and a knee characteristic portion. The modification unit modifies the input/output characteristics such that output level is increased within a range of part of input level corresponding at least to the gamma characteristic portion, in comparison with the input/output characteristics of the image data with the reference level of brightness.

Abstract: A triggering system and process for a form reader is shown using a histogram of the optical scene. The form reader is open on three sides with a camera facing a platen on to which a form is placed. The camera converts the light rays reflected from the platen into a video stream that is sent to a processor. A change in content of a first light intensity level contrasted to the content of a second light intensity level is used to determine when the form enters the scene. Illustratively, the first light intensity level represents black levels and the second light intensity levels represent white levels. A threshold is pre-determined that isolates the first light intensity content, and when the first light intensity content remains constant (after the presence of a form) the form is deemed to be still wherein the system may then read the information on the form.

Abstract: High frequency components of a video signal are attenuated for avoiding aliasing when the video signal is corrected by a non-linear gamma correction circuit. Such high frequency components arise from the video signal harmonics, and also are generated in image contour processing of the video signal. The high frequency components are band limited, thereby linearizing the gamma correction circuit and preventing aliasing. Up-converting the sampling frequency increases a desired band limitation area and defers the generation of high frequency components that cause aliasing. The non-linear gamma correction function is divided into a plurality of sections which are replaced by respective straight-line segments each represented by a linear expression, and gamma correction is effected with a straight-line segment corresponding to the amplitude of the digital video signal.

Abstract: A gamma correction device performs gamma correction on an input signal from an image capturing element based on at least one correction curve having a predetermined input-output characteristic in an image capturing apparatus. The correction curve is composed of a logarithmic curve whose slope at the origin is 5.0 or less or a composite of a curve segment lying from the origin to a predetermined level of an input signal complying with the ITU-709 standard and a logarithmic curve segment lying above the predetermined level of the input signal, wherein both curve segments are continuously combined and have the same slope at the predetermined level.

Abstract: Techniques are disclosed to improve quality of images that may be blurred or underexposed (e.g., because of camera shake, taken in dim lighting conditions, or taken of high action scenes). The techniques may be implemented in a digital camera, digital video camera, or a digital camera capable of capturing video. In one described implementation, a digital camera includes an image sensor, a storage device, and a processing unit. The image sensor captures two images from a same scene which are stored on the storage device. The processing unit enhances the captured images with luminance correction.

Abstract: The present invention includes a film or video image pickup signal recording/reproduction system having an image pickup apparatus outputting an image pickup signal, a recording apparatus recording the image pickup signal, a reproduction apparatus reproducing the recorded signal, a characteristic conversion apparatus switching the characteristic of the reproduced signal, and a display apparatus displaying the signal output from the characteristic conversion apparatus. The image pickup apparatus has two kinds of gamma curve characteristics. The gamma curve characteristic data is recorded by the recording apparatus and extracted by the reproduction apparatus. The gamma curve characteristic of a reproduction image is switched by the characteristic conversion apparatus depending on the data. The image is output on a display apparatus.

Abstract: A first processing circuit subjects image data output from an A/D converter circuit to a first signal process to produce first image data. A second processing circuit subjects image data to a second signal process, which is independent of the first signal process, to produce second image data. The first and second processing circuits execute the first and second signal processes in a parallel manner to output the first and second image data to a display device and a system microcomputer.

Abstract: An imaging apparatus includes an image pickup unit generating image data, a selecting unit selecting any one of a first photographic mode that does not correct dark area gradation of the image data and a second photographic mode that corrects the dark area gradation of the image data, a gradation conversion processing unit performing a gradation conversion processing according to a first input-output characteristic when the first photographic mode is selected, and performing a gradation conversion processing according to a second input-output characteristic different from the first input-output characteristic when the second photographic mode is selected, and a correcting unit performing a correction of improving lightness of the dark area gradation of the image data when the second photographic mode is selected. Therefore, when correction of the dark area gradation is performed, the lightness of the whole image can be maintained while the contrast of a highlight area is improved.

Abstract: Briefly, a camera according to the present invention includes a first signal processing system having a first gamma conversion processing unit for subjecting an output from an image pick-up device to gamma conversion processing and a luminance signal generating unit for generating a luminance-system signal based on an output from the first gamma conversion processing unit, and a second signal processing system having a color signal generating unit for generating a color-system signal based on an output which is the output from the image pick-up device and which is not subjected to the gamma conversion processing.

Abstract: Methods and apparatuses for performing gamma corrections to maintain a plurality of colors substantially consistent with a color point. In one aspect of the present invention, a method to generate correction functions for performing color correction for a device for signals of different color components in a color space includes: generating a first correction function for a first color component in the color space; and generating second correction functions for second color components in the color space by reducing first color differences between a target White point and white points of a plurality of grays corrected by the first and second correction functions. The second color components are the color components in the color space other than the first color component. The first color differences are minimized relative to a chromaticity diagram.

Abstract: The techniques and mechanisms described herein are directed to a system for stylizing video, such as interactively transforming video to a cartoon-like style. Briefly stated, the techniques include determining a set of volumetric objects within a video, each volumetric object being a segment. Mean shift video segmentation may be used for this step. With that segmentation information, the technique further includes indicating on a limited number of keyframes of the video how segments should be merged into a semantic region. Finally, a contiguous volume is created by interpolating between keyframes by a mean shift constrained interpolation technique to propagate the semantic regions between keyframes.

Abstract: Some embodiments provide an intuitive system for digital image processing. In some embodiments, the system of the present invention allows a user to enhance digital images that appear dark or dull. In some embodiments, the user activates an image enhancement button on a graphical user interface using cursor control device such as a mouse button. In some embodiments, the digital image enhancement system is implemented using a nonlinear brightness level transformation correction and a pseudo gamma correction.

Abstract: The present invention enables processing results which are more accurate and which have higher precision as to events of the real world to be obtained. (An inverse gamma correction unit 5001 applies inverse gamma correction to an input image wherein light signals of the actual world have been projected and a part of the continuity of the light signals of the actual world has been lost, and which has been subjected to gamma correction. A data continuity detecting unit 101 detects, in the input image subjected to inverse gamma correction, data continuity corresponding to the continuity of light signals of the real world. An actual world estimating unit 102 estimates the light signals by estimating the continuity of the light signals of the real world, based on the data continuity. An image generating unit 103 generates an output image from the estimated light signals.

Abstract: A detecting section for detecting a high-luminance object signal is provided. By using resulting detection data, an exposure control is performed so that the white levels of high-luminance objects do not become unduly high. Low-luminance objects are blackened under such imaging conditions. A gamma correction circuit is provided that can make the low-luminance objects appear good by compensating for the blackening. A control of changing the characteristic of the gamma connection circuit in real time in accordance with the object condition is performed, whereby the luminance level is raised in a low-luminance range. As a result, when wide-dynamic-range objects including the high-luminance objects and the low-luminance objects are shot, unduly high white levels of high-luminance objects and blackening of low-luminance objects are prevented and a good image is thereby produced.

Abstract: A cascaded imaging storage system for a pixel is disclosed for improving intrascene dynamic range. Charges accumulated in a first capacitor spill over into a second capacitor when a charge storage capacity of the first capacitor is exceeded. A third capacitor may also be provided such that charges accumulated by said second capacitor spill over into the third capacitor when the charge storage capacity of the second capacitor is exceeded.

Abstract: A gamma correction method and system, which performs a gamma correction on an n-bit video signal to thus generate a gamma correction value. At first, a first primary index and a first sub-index are obtained by performing an index mapping on a value of the video signal. Next, a first gamma value is obtained by performing a table lookup on the first primary index and the first sub-index. Next, a second primary index and a second sub-index are obtained by performing the index mapping on the first gamma value. Next, multiple thresholds are obtained by performing the table lookup on the second primary index and the second sub-index. Finally, the value of the video signal and the multiple thresholds are compared to accordingly correct the first gamma value and generate the gamma correction value.

Abstract: Provided are a method and apparatus for generating a wide color gamut signal in an image capturing device, which can simplify a calculation process and minimize color distortion therein. The apparatus includes a gamma-correction unit gamma-correcting a picked-up image signal by using gamma curve information predetermined according to an output format; an interpolation unit interpolating the gamma-corrected image signal as a linear image signal which is to be expressed on a display; a color gamut conversion unit converting the interpolated image signal into a standard RGB signal by using a color conversion matrix; a color expansion unit expanding the standard RGB signal to a wide color gamut signal by using a gamut conversion matrix; and a signal correction unit correcting the wide color gamut signal by a predetermined correction gain value.

Abstract: The electronic camera has an imaging device that images a subject with subject reflectance R (%) with a dynamic range wider than that at displaying or printing to acquire image data and a recording device that converts the image data acquired by the imaging device with a predetermined function and records the converted image data and the information on the function as digital values (digit). Therefore, a printed image with an automatically or manually corrected density can be obtained at the displaying or the printing.

Abstract: A new image enhancement process based on an integrated neighborhood dependent nonlinear approach for color images captured in various environments such extremely low lighting, fog or underwater. The new process is a combination of two independent processes: luminance enhancement and contrast enhancement. The luminance enhancement, also regarded as a process of dynamic range compression, is essentially an intensity transformation based on a specifically designed nonlinear transfer function, which can largely increase the luminance for dark regions of the image but only slightly change the luminance for the bright regions of the image. The contrast enhancement transforms each pixel's intensity based on the relationship between the pixel and its surrounding pixels. The output of the contrast enhancement is a power function of the luminance of the input image.

Abstract: A grayscale image with corrected contours, which is suitably applicable to the art of recognition of objects, is obtained using a grayscale image and a distance image of a subject. The contour of the grayscale image where a grayscale contour image extracted from the grayscale image and a distance contour image extracted from the distance image agree with each other in contour, is corrected to generate the grayscale image with corrected contours. It is possible to highlight or emphasize the boundary of the subject, and a contour correcting process, which is different from the ordinary contour correcting process, can be carried out on a boundary of the subject.

Abstract: Provided is an image capturing apparatus capable of outputting an image in a form displayable by a display apparatus, while making use of a space resolution and a temporal resolution of a captured image. A monitoring system includes an image capturing section that captures an image; an output image generating section that generates an output image from the image captured by the image capturing section; a matching determining section that determines whether an object that matches a predetermined condition exists in the image captured by the image capturing section; and an output section that outputs, by embedding in the output image, an image of a subject indicated by the object having a data amount larger than a data amount of an image of the object in the output image.

Abstract: The anti-blooming structure of an image sensor is supplied with varying voltages during different integration periods such that charges generated in response to low level light are fully captured, whereas charges generated in response to a bright light spill over in a controlled manner. Accordingly, sensor's response may be generated to result in higher gains at low light levels and progressively lower gains at the higher light levels.

Abstract: An apparatus and method for handling special windows in a display comprises a window manager in an operating system that is called by application programs to create special windows. The window manager embeds static key signals including encoded special window information, such as the coordinates of a window area to be specially processed, into a video RAM. An existing video interface scans the video RAM and transmits display information, including the key signals, to the display. The present invention further comprises a window decoder in the display, that detects the key signals, extracts the encoded special window information, and controls display circuitry performing the desired special processing. The key signal encoding scheme does not create visually discernible display aberrations that could distract the user or interfere with normal window management.

Abstract: It is an object of this invention to reduce image sensing errors due to wrong white balance control using wrong color temperature information in an image sensing device capable of performing white balance control using a color image signal from an image sensing device. In order to attain the above object, when the color in the vicinity of the locus of a blackbody cannot be extracted in detection of a color temperature in a color image signal, color temperature information is corrected on the basis of a piece of color temperature information output from a calorimetric sensor, thereby controlling the white balance of a color image signal output from an image sensing element. The number of achromatic data extracted from the color image signal is counted. The color temperature is calculated by weighting a color temperature obtained from the color image signal and that obtained from the colorimetric sensor in accordance with the count, thereby performing white balance control.

Abstract: Providing a signal processing method for image synthesis with reduced computation load, a signal processor circuit for image synthesis with reduced computation load which allows manufacturing at a low production cost, and imaging apparatus which uses the signal processing method and the signal processor circuit. The signal processor circuit includes: a table storage area for storing an LUT; a table overwriting section for overwriting an LUT written into the table storage area with another LUT; and an arithmetic operation section for performing arithmetic operation on a first digital signal or a second digital signal based on the LUT written into the table storage area each time an LUT is written into the table storage area and synthesizing the first digital signal and the second digital signal.

Abstract: The present invention relates to an image processing device enabling detection of a mixture ratio indicating the state of mixture between multiple objects. A contour region information generating unit 421 and a normal equation generating unit 422 extracts contour region pixel data within a frame of interest positioned at a contour region with approximately a same mixture ratio, extracts corresponding pixel data from a frame different to the frame of interest, extracting background pixel data corresponding to the contour region pixel data or the corresponding pixel data, and generating an equation wherein the mixture ratio is an unknown number, based on region specifying information specifying a non-mixed region made up of a foreground region and background region and a mixed region. A least square approximation unit 423 detects the mixture ratio by solving the equation. The present invention can be applied to signals processing devices for processing image signals.

Abstract: A received light quantity detection device where high-sensitivity pixels and low-sensitivity pixels are formed is used for photometry. It is possible to perform measurement over the low range (for example, 0[EV] through 8[EV]with a single occasion of photometry. In the case that both the high-sensitivity pixels and the low-sensitivity pixels are saturated, it is possible to perform further measurement over the high range (for example, 8[EV] through 16[EV]) by narrowing the aperture or increasing the electronic shutter speed for retried photometry with a retried photometry. This reduces the time required to calculate a correct exposure value on image pickup apparatus such as a camera.

Abstract: An apparatus processes a video image. The apparatus includes an imaging device, a frame grabber device, and a host computer. The imaging device (20) produces a gray level image representing the video image. The frame grabber device conducts preprocessing functions on the gray level image and produces a plurality of image types from the gray level image. The host computer has a memory for storing the plurality of image types. The plurality of image types are transferred directly from the frame grabber device to the memory of the host computer.

Abstract: The present invention relates to an image processing apparatus, which calculates the histogram of an image on the basis of moving image information that is input in real time, and corrects and outputs the brightness of the image using the histogram in real time. The apparatus for controlling the brightness of moving image signals according to the present invention includes a cumulative difference function detection means, an image storage means and a brightness adjustment means. The cumulative difference function detection means calculates a cumulative difference function using upper n bits of each input image. The image storage means stores therein the input image. The brightness adjustment means adjusts the brightness of the image in real time using the cumulative difference function calculated by the cumulative difference function detection means when the input image stored in the image storage means is displayed.

Abstract: An image processing apparatus is disclosed which carries out correction processing of an image signal made up of a plurality of bits. The apparatus includes: a correction processing unit configured to perform gamma correction of an input image signal; and a fine control processing unit configured to establish as desired a plurality of types of correction data in accordance with a plurality of fixed gray-scale levels of the input signal in order to fine-control a transmittance characteristic, known as a V-T curve, regarding an applied voltage by performing computations on the input image signal gamma-corrected by the correction processing unit using the established correction data.

Abstract: The present invention relates to a method for determining the reference image of an image sensor comprising a matrix of detector pixels. The method comprises the acquisition of a black image IN and two images I1 and I2 acquired in linear detection zones of the sensor. The reference image is written: IR1=(Rm* I1?I2)/(Rm?1) with I R ? ? 1 = ( R m × I 1 - I 2 ) / ( R m - 1 ) ? with ? ? Rm = 1 N ? ? i , j ? I 2 ? ( i , j ) - I N ? ( i , j ) I 1 ? ( i , j ) - I N ? ( i , j ) , wherein IK (i,j) represents the value of the pixel of the image IK detected by the pixel detector situated at the intersection of the row i and the column j of the detector pixel matrix, and N represents the total number of pixels in the matrix.

Abstract: An image processing apparatus for automatically improving the contrast of an input image that is obtained from a digital camera or the like, and obtaining a sharper and clearing image. A contrast improvement unit (11) performs a contrast improvement process on the input image by comparing an object pixel in the input image with pixels in the surrounding area. An image combination unit (12) combines the enhanced image obtained by the contrast improvement process with the input image. The combined image is then output to a desired device such as a printer by an image output unit (13).

Abstract: A circuit, method and computer program product wherein a nonlinear signal outputted from a nonlinear circuit is nonlinearly processed in two steps using a main circuit and an assistant circuit. The main circuit performs a first relatively rough nonlinear process (main correction), and the assistant circuit performs fine a second adjustment (sub-correction) process on the nonlinearly-processed signal resulting from the first process.

Abstract: The liquid crystal display device inputs a signal, corrected by a correction circuit provided with a sigmoid inverse function generator, to a source driver. A sigmoid function which is an S-shaped function is used to approximate an input/output characteristic (applied voltage-transmittance curve) of a liquid crystal panel. The sigmoid inverse function generator converts an input signal by using an inverse function of the sigmoid function obtained by performing the approximation. A ? conversion circuit provided on the correction circuit and the sigmoid inverse function generator realize the desired ? characteristic regardless of a characteristic of the liquid crystal panel.

Abstract: An electronic camera includes an image-capturing element that captures a subject image and outputs image-capturing signals each corresponding to a pixel; and a control device that executes gradation correction on the image-capturing signals output by the image-capturing element.

Abstract: An image pick-up device for producing a synthesized image signal having a wide dynamic range by partially exchanging a plurality of image signals from a solid state image sensing element in an image synthesizing unit (41), said image signals being obtained by picking-up a subject moving on a bright background with different exposure amounts, including a synthetic unsuitable portion detecting unit (42, 44) for detecting a synthetic unsuitable portion by comparing said plurality of image signals picked-up with different exposure amounts, a synthetic unsuitable portion correcting unit (46, 48) for correcting a pixel signal of said synthesizing unsuitable portion to derived a corrected synthesized image signal, and a low pass filter (47) for combining said corrected synthesized image signal from said synthetic unsuitable portion correcting unit with said synthesized image signal from said image synthesizing unit to derive a corrected synthesized image signal.

Abstract: In image processing apparatus and method for displaying and printing a person image photographed by a digital camera, it is possible to automatically correct image data and output the person image of an optimum characteristic. In this apparatus, an image obtaining processor obtains the image data from a recording medium, a face region extraction processor extracts a face region of a person from the obtained image data, an image feature amount calculator calculates an image feature amount of the extracted face region, a correction effect inference processor infers whether or not a correction effect can be obtained by correcting a characteristic of the image data, based on the calculated image feature amount, and an image correction processor corrects the characteristic of the image data based on the image feature amount and thus outputs post-correction image data when it is inferred that the correction effect can be obtained.

Abstract: The present invention is directed to a digital still camera (1) using CCD (Charge Coupled Device) image sensor as image pick-up device. This camera (1) comprises an image memory (18) in which plural images obtained by picking up images of the same object by different exposure values are stored, an image data adding circuit (17) for synthesizing the plural images stored in the image memory (18) to generate synthetic image in which dynamic range is broad, a Y gradation correction circuit (24) and a multiplier circuit (26) for compressing gradation of the synthetic image generated by the image data adding circuit (17), and a controller (29) for generating gradation conversion table for carrying out gradation compression.

Abstract: A CPU of a color printer performs gamma correction and a matrix operation M on an RGB color space image data derived by a matrix operation S. Using gamma correction value settings, the CPU performs gamma conversion of image data. Matrix operation M converts the RGB color space to an XYZ color space. When performing matrix operation M, the CPU refers to a PrintMatching tag and performs the matrix operation using a matrix (M) that corresponds to the indicated color space, in order to reflect the color space used for generation of image data.

Abstract: A luminance intensity of pixels of an input digital image is corrected for generating a corrected digital image. A luminance of each pixel is calculated as a function of the luminance of a corresponding pixel in an original image according to a parametric function. A mask of the input digital image to be corrected is generated according to a bilateral filtering technique. For each pixel of the input digital image, a respective value of at least one parameter of the parametric function is established based upon the luminance of a corresponding pixel of the mask.

Abstract: Provided are an apparatus and method of gamma correction, and more particularly, an apparatus and method for varying a gamma curve according to a brightness level of a detected image signal to adaptively perform gamma correction, in a digital image processor. The gamma correction apparatus in the digital image processor includes a brightness level detector detecting a brightness level from an image signal generated by capturing an image, a gamma curve calculator moving a start point and/or an end point of an existing gamma curve for correcting an input brightness level to a predetermined output brightness level, according to the detected brightness level, and calculating a new gamma curve, and a gamma corrector correcting an input brightness level of the image signal using the new gamma curve, and outputting the corrected brightness level.

Abstract: A method for producing an extended color gamut luminance-chrominance digital image from a captured digital image includes determining an estimate of the colors of the captured digital image of an original scene and further processing to produce an extended range output RGB image value including values outside the range that can be displayed on the output image display device, and producing an extended color gamut luminance-chrominance digital image by transforming the extended range output RGB image values to a luminance-chrominance representation.

Abstract: A digital imaging system includes an image sensor, a frame buffer and a tone correction circuit. The tone correction circuit computes tone corrected pixel data using one or more tone correction curves. In operation, tone corrected pixel data for a first pixel is computed by generating a pixel mask for an m×n neighborhood of pixels surrounding the first pixel, applying a blending mask of weight factors to the pixel mask and computing a selector value based on the pixel mask and weight factors associated with the blending mask. The selector value is used to derive a first tone correction curve for use to compute the tone corrected pixel data for the first pixel. The first tone correction curve can be selected from the multiple tone correction curves based on the selector value or it can be derived by blending multiple tone correction curves based on the selector value.

Abstract: For each paper type, a plurality of two-dimensional excitation characteristics tables Ti are provided in one to one correspondence with a plurality of colors i. The excitation characteristics table Ti for each color i contains a plurality of sets of excitation-reflectance data Bi (?0, ?) in a two-dimensional matrix form, for a plurality of combinations of incident light wavelengths ? and reflected light wavelengths ?0. The excitation-reflectance data Bi (?0, ?) indicates the ratio of the amount of the reflected light wavelength ?0 generated in response to incidence of the incident light wavelength ?, with respect to the amount of the incident light wavelength ?. Using the two-dimensional excitation characteristics table Ti corresponding to the user's selected paper type and using the spectral radiation characteristics S(?) of the user's selected light source type, Equations (9)-(11) are calculated to create an output profile, and color conversion is performed by using the output profile.

Abstract: Each gamma characteristic adjusting unit in a gamma correcting circuit selects a reference voltage from basic voltages generated by a basic voltage generating circuit based on correction adjustment data and selects a reference-voltage output terminal from reference-voltage output terminal candidates of a gamma correction resistor circuit as a target from which the reference voltage is to be output. As double adjustments based on such two-stage selection are possible, the adjustment range for the gamma characteristic can be made wider.

Abstract: An image-sensing apparatus has an area sensor 1 that outputs image data by logarithmically converting the brightness of light incident thereon, a black-level detector 2 for detecting the black level BL of the image data at which the image data has the lowest signal level, a white-level detector 3 for detecting the white level WL of the image data at which the image data has the highest signal level, a calculation formula determiner 4 for determining, in accordance with the detected black and white levels BL and WL, the formula to be used to convert the signal level of the image data, and a dynamic range converter 5 for converting the signal level of the image data using the calculation formula determined by the calculation formula determiner 4.

Abstract: In image input devices such as digital still cameras, processing is speeded up and power consumption is reduced by arranging in a RPU (23) performing real time processing of a pixel data from a CCD (21), such that only special exceptional image processing not being prepared previously is subjected to a software program processing in a CPU (24) and, in post processing in which a general image processing is carried out, a pixel data temporarily stored in a main memory (29) is inputted again to the RPU (23) and then processed. This enables to sharply speed up processing, and minimize a prolonged processing in the CPU (24) to reduce power consumption, when compared to the case of executing by software problem processing.

Abstract: Images having been subjected to image processing optimal for each user or each output device are obtained. Correction function calculation means calculates correction functions for correcting image data sets for each user ID or for each device ID, and correction function storing means stores the calculated correction functions. When the image processing is carried out on the image data sets, the correction functions corresponding to the user ID or the device ID added to the image data sets are searched for and correction parameter calculation means calculates correction parameters based on the correction functions. The image processing is then carried out on the image data sets according to the correction parameters to generate corrected image data sets.