Abstract: There is provided an image reading apparatus that is capable increasing the detection accuracy for dust, scratches, dirt, and the like. Sixty-four lines of sampling points on a reference standard white plate are read, shading correction and averaging are carried out the read image data to suppress random noise components in the image data, the data is then stored in a sampling memory, and dust detection is carried out on the data stored in the sampling memory. Alternatively, shading correction and dust detection are carried out on image data that has been subjected to linear interpolation. It is thus possible to increase the accuracy of detection of dust, scratches, dirt, and the like while ensuring that shading correction is performed at high speed.

Abstract: A method of compensating a zipper image by a K-value, and a method of calculating the K-value. Whether the nth primitive pixel of the mth line is obtained by primary line scan is determined. If the nth primitive pixel of the mth line is obtained by primary line scan, the nth primitive pixel of the mth line is compensated as the nth primitive pixel of the mth line minus a sum of the (n?1)th primitive pixel of the (m?k)th line and the (n+1 )th primitive pixel of the (m?k)th line multiplied by the K-value. If the nth primitive pixel of the mth line is obtained by secondary line scan, the nth primitive pixel of the mth line is compensated as the nth primitive pixel of the mth line minus a multiplication of the K-value and a sum of the (n?1)th primitive pixel of the (m+k)th line and the (n+1)th primitive pixel of the (m+k)th line.

Abstract: A pseudo-random number generator comprises a controller, a plurality of LFSRs, a FIR filter and a normalizer. The pseudo-random number generator initializes the LFSRs in such a manner that each LFSR has a predetermined phase difference with the other LFSRs, sets the coefficient of the FIR filter in accordance with the desired frequency characteristic of a noise signal, and sets a parameter in the normalizer. The operation of the LFSRs is started, thereby acquiring a noise signal having the desired frequency characteristic.

Abstract: A method and program product for real-time correction of non-functioning pixels in digital radiography, where the method comprises: receiving a list of non-functioning pixels; determining which neighboring functioning pixels are needed to correct the non-functioning pixels; organizing those neighboring functioning pixels and corresponding non-functioning pixels into a plurality of groups by a number of pixels used to perform correction; and performing correction of data from non-functioning pixels within one of the plurality of groups and subsequently performing correction of data from non-functioning pixels within another one of the plurality of groups.

Abstract: In the method, a digital image is received. A granularity model is constructed of each of the toner stations. A noise table is produced. The noise table is based on the granularity models and is adaptive to the content of the digital image. Noise is reduced in the digital image using the noise table. The digital image is divided into a plurality of color records, each corresponding to a respective toner station. The color records of the noise reduced digital image are printed using respective toner stations. Each granularity model defines a toner applied by the respective toner station.

Abstract: A system and method are provided that compensates for noise in a captured image. One embodiment comprises scanning an image a predefined number of times with a plurality of pixels, receiving light information from each of the plurality of pixels each time the image is scanned, converting the received light information into a plurality of data values, each of the data values corresponding uniquely to light information from one of the plurality of pixels, generating a plurality of pre-divided data values by dividing each of the data values by a number corresponding to the number of times that the image is scanned, and adding corresponding ones of the pre-divided data values together such that an average data value is determined uniquely for each of the plurality of pixels so that noise is compensated by the averaging of the data values.

Abstract: A system and method for correcting a defect in an image, such as a ghost defect or a reload defect, by compensating for the defect. A defect model is created with a source target function that represents a source level with respect to a target level. A test output image is created on which the test data is measured. State data representing a state of the imaging device, previously printed images or the current image are inputted to a controller. An image correction factor is outputted from the controller based on the test image measurement data, the state data, the previously printed images, and the current image to the image path actuator. A corrected image is created based on the image correction factor.

Abstract: An electronic correction system and method for correcting optical anomalies, namely distortions, color non-convergence (excluding axial chromatic aberration) and luminance (or chrominance) non-uniformity. Each effect is modeled as a transformation in either spatial (positional) space or color space. Representing the effects as transformations of digital pixel data, allows the different anomalies to be resolved within a common framework, namely that of image ‘warping’. The anomaly, having been expressed as a pixel transformation, is then eliminated by electronically applying the inverse transformation. This process is equivalent to digitally manipulating or warping the image in position and/or color space and accordingly this can be achieved using commercially known warping circuits. In addition, the transformation can also contain a component to additionally perform any application specific image warping (e.g. scaling and geometric transformations).

Abstract: A dithering pattern that is generated based on a spatial operation is used for a Bit-Depth Extension (BDE) technique for preventing contouring artifacts in an image displayed by a display having a bit-depth that-is less than the bit-depth of the image. The dithering pattern can be based on achromatic visual model or a spatio-chromatic visual model. The dither pattern is formed by shaping a pseudo-random noise signal by an equivalent noise visual model that is based on an array of pixels. Alternatively, the array of pixels is based on an image, or a determinate array of pixels.

Abstract: There is described a signal processing apparatus, which conducts processing of a signal outputted from an image capturing element that converts an optical image obtained by irradiating light on an object such as document to an electric signal. The apparatus includes: a sample-and-hold section to sample and hold a black signal level and an image signal level, both included in an analogue image signal inputted from an image capturing element; an analogue-to-digital converting section to convert the analogue image signal to digital image data within a predetermined number of conversion steps, which is larger than a number of conversion steps corresponding to a differential value between the black signal level and the image signal level; and a digital subtracting section to subtract black digital-image data representing the black signal level from signal digital-image data representing the image signal level, both being converted by the analogue-to-digital converting section.

Abstract: An image de-ringing filter system and method are provided. The method comprises: accepting image pixels; collecting data from a first group of pixels neighboring a test pixel; in response to the first group data, deciding if the test pixel includes image ringing artifacts; collecting data from a second group of pixels neighboring the test pixel; in response to the second group data, generating a filtered value (FV); and, replacing the test pixel actual value with FV. Typically, collecting data from the first and second group of pixels includes the performance of a mathematical operation. For example, a matrix may be defined for the multiplication of the first group of pixels. Values of pixels on a first side of the coordinate axis may be subtracted from pixels on a second side of the coordinate axis, opposite of the first side. Then, the difference is compared to a threshold.

Abstract: A color conversion definition correction apparatus corrects a color conversion definition defining a relation between first color data representative of a color by coordinates on a first color space and second color data representative of a color by coordinates on a second color space in such a manner that a plurality of first color data has a one-to-one correspondence with a plurality of second color data. A smoothing processing is applied to the second color data. A color difference between the reference color set up and a color represented by the second color data subjected to the smoothing processing is determined. The second color data subjected to the smoothing processing is corrected, when the color difference is larger than the reference color difference, in such a manner that a color difference between a color represented by the second color data and the reference color is small.

Abstract: An image reading apparatus detecting scratch and dirt information of a film document without the need for complex structures and complex control in the image reading apparatus. The apparatus can read a transmissive original document and/or a reflective original document. The apparatus includes a first light source that illuminates the transmissive original document, a second light source that illuminates one of the reflective original document and the transmissive original document, an image sensor that generates electronic image data, a detector unit that detects non-image information from the image data, and a correction unit that corrects the image data, based on the non-image information detected by the detector unit.

Abstract: A technique for the modification of sub-pixels to hide defects for defective sub-pixels.

Abstract: A method for removing streaks from a scanned image includes performing a scanner light source OFF scan to generate a dark image having M rows of pixels and N+W columns of pixels; generating a line noise profile for the N columns of pixels of the dark image; performing a scanner light source ON scan to generate a regular image having M rows of pixels and N+W columns of pixels; processing the W columns of pixels of the regular image to detect a magnitude of the streak in the regular image; use the magnitude of the streak and the line noise profile to predict an amount of dark noise removal for each of the N columns of pixels of the regular image at the location of the streak; and subtracting the predicted amount of dark noise removal for each of the N columns of pixels from the respective N columns of pixels of the regular image.

Abstract: An image processing apparatus generates, from original image data, low- and high-frequency components of the original image data. By smoothing at least some of the high-frequency components, the second high-frequency component is generated. Image data is generated on the basis of the generated second high-frequency component.

Abstract: A method performed by a processing system is provided. The method comprises performing a first set of correlations between a first plurality of pixel values in a first frame and a target pixel value in a target frame of a digital video across all of a plurality of color channels of the target pixel value, performing a second set of correlations between the first plurality of pixel values in the first frame and the target pixel value in the target frame across less than all of the plurality of color channels of the target pixel value, and determining whether the target pixel value is an artifact using the first set of correlations and the second set of correlations.

Abstract: A method for interpolating a pixel within an image is provided. The image has a plurality of pixels arranged in a matrix format. The method includes: detecting if there is an edge in a block of the image according to frequency information of the block associated with the pixel; determining an interpolation direction for the pixel according to the detection result and the frequency information; and interpolating the pixel according to the determined interpolation direction. Additionally, a device for implementing the method is also provided.

Abstract: An image reading device includes: a solid-state image sensor for converting image information into an electric signal; an analog processing section for generating an analog processing signal by sampling and amplifying the electric signal at a sampling position; an A/D converting section for converting the analog processing signal into a digital signal; a pulse generating section for generating a control pulse to the solid-state image sensor, the analog processing section and the A/D converting section; and a control section for controlling a pulse generating timing of the pulse generating section, wherein the analog processing section comprises an amplification processing section for amplifying the electric signal so as to set an output voltage to a set voltage, the pulse generating section includes a varying section for varying the sampling position, and the control section includes an optimizing section for optimizing the sampling position based on variance of amplification gain values.

Abstract: A method of reducing spatial noise in an image. Low-pass (smoothing) filters are calculated simultaneously from three successive image rows. Three blocks (m1, m2, m3) are associated with the three successive image rows, and the blocks are processed in row-major order. This implementation is applicable to both luminance and chrominance. The number of smoothing parameters is reduced to one. The technique is applicable to both luminance and chrominance. Directional mapping is used. Extension of the technique to spatial filtering using a 5×5 neighborhood (using five successive image rows) is described. Embodiments of the method using the MMX instruction set are described.

Abstract: This invention provides an image processing apparatus which can effectively remove conspicuous noise contained in image data, while suppressing deterioration of image information. Image data containing noise is input from an input terminal (100). Based on the output condition upon outputting image data after noise is removed, a parameter determination module (103) determines predetermined parameters used in a noise removal process. An example of the output condition is information associated with a resolution upon outputting image data. An individual noise removal module (104) removes noise contained in the image data using the parameters, and image data after the noise has been removed is output from an output terminal (105).

Abstract: A method for increasing signal to noise ratio is disclosed. The method can automatically detect saturation output voltage of the photosensors via adjusting exposure time or illumination intensity so as to obtain optimum output voltage of the photosensors as well as high signal to noise ratio that can generate high quality images.

Abstract: A black level correcting device includes: an A/D converting section converting a result of subtracting a feedback signal from an input pixel signal into a pixel value to be output; and a feedback controlling section generating the feedback signal and having a holding section, a feedback gain adjusting section, etc. The holding section clamps a maintaining level to the level of the feedback signal while pixel signals of OB pixels are output, and maintains and outputs the maintaining level while pixel signals of valid pixels are output. The feedback gain adjusting section multiplies the feedback signal by clamp accelerating gain in synchronization with starting readout of the pixel signals from the OB pixels. Accordingly, clamp time of the holding section is shortened, enabling stabilization of the maintaining level at a convergence level before starting readout of the pixel signals from the valid pixels. Consequently, a sag can be reduced.

Abstract: A method for removing blocking artifacts from moving and still pictures, comprising classifying horizontal and vertical boundaries in each picture as blocky or non-blocky; for each blocky boundary, defining an adaptive, picture content-dependent, one-dimensional filtered pixels region of interest (ROI) that crosses the boundary and is bound at each of its ends by a bounding pixel; defining a finite filter having a length correlated with the length of the ROI; defining a filtering pixels expansion that uniquely determines the padding values of the finite length filtered pixels ROI for the finite length filtering; and filtering the ROI pixels using the finite filter and the filtering expansion.

Abstract: A method of automatically correcting dust artifact within images acquired by a system including a digital camera includes determining probabilities of dust artifact regions corresponding to pixels within a digitally-acquired image based at least in part on a pixel analysis of the region in view of predetermined characteristics indicative of the presence of a dust artifact region. The dust artifact regions are associated with one or more extracted parameters relating to the optical system when the image was acquired. A statistical dust map is formed including mapped dust regions based on the dust artifact determining and associating operations. Digital data is corrected corresponding to correlated dust artifact regions within the acquired image based on the associated statistical dust map.

Abstract: An image correction method able to avoid error image. According to opposite properties of black and white, only the last few bits of the scanned digital signal are extracted for black correction, while only the first few bits of the scanned digital signal are extracted for white correction. Further, the most significant bit of the digital signal is 1 for white correction. Therefore, the unwanted LBB effect on the scanned image caused by dust or spot on the correction document is avoided. In addition, as only a few bits of the scanned digital signal are extracted, the requirement in memory capacity is reduced.

Abstract: An image reading apparatus is provided which allows a reading device fixed at a reading position to read images from a document while transporting the document. The apparatus includes a correcting unit adapted to perform correction processing associated with image reading performed by the reading device; a calculating unit adapted to calculate a time interval from one document to the next document that are being transported; a scheduling unit adapted to divide the correction processing into a plurality of steps and schedule the execution of the steps on the basis of the calculated time interval; and an executing unit adapted to sequentially execute the steps scheduled by the scheduling unit every time a document passes through the reading position.

Abstract: An apparatus and method of processing shoot artifacts of an image signal includes a maximum gradient value calculation part to set a window of a predetermined size based on a current pixel of an input image signal and to calculate a maximum gradient value based on values of pixels in the window, a limit value calculation part to calculate a limit value corresponding to the maximum gradient value, a dilation amount calculation part to calculate a dilation amount corresponding to the current pixel based on the calculated limit value and a pixel difference between the current pixel neighboring pixels of the current pixel, and a pixel value conversion part to add a current pixel value to a value obtained by multiplying the calculated dilation amount by a predetermined gain value.

Abstract: In an image reading apparatus according to the invention, the switching frequency of a switching power supply is set to a value equal to integral multiples of a reading frequency corresponding to each line, thereby correcting, for example, uneven image density due to ripples in a power supply voltage. Further, the switching of the switching power supply is synchronized with a horizontal synchronizing signal output from a scanner, thereby causing the positions of the ripples to correspond between lines for correcting, for example, uneven image density.

Abstract: Pre-processing techniques for processing an image to improve the distinctiveness of an information pattern captured in the image before the information pattern is analyzed in a decoding process. The brightness of an image first is normalized by dividing the image into blocks of areas, such as pixels. A brightness distribution value then is determined for each area of the image by fitting the brightness of its surrounding blocks using bilinear interpolation and extrapolation, and a normalized brightness value for each area can then be obtained by dividing the original brightness value by the brightness distribution value. Next, masks are created to distinguish the information pattern from content captured in the image. The masks may be generated based upon contrast differences between the brightness of pixels representing the information pattern, the brightness of pixels representing content, and the brightness of pixels representing the background of the writing medium.

Abstract: A computer-based technique for detecting edges in gray level digital images employs fuzzy reasoning to analyze whether each pixel in an image is likely on an edge. The image is analyzed on a pixel-by-pixel basis by analyzing gradient levels of pixels in a square window surrounding the pixel being analyzed. An edge path passing through the pixel having the greatest intensity gradient is used as input to a fuzzy membership function, which employs fuzzy singletons and inference rules to assigns a new gray level value to the pixel that is related to the pixel's edginess degree.

Abstract: An image reading apparatus having a visible light source for emitting visible light, an invisible light source for emitting invisible light, an imaging optical system for irradiating a document by these light sources to form optical images of the document, and a CCD for photoelectrically converting the optical images of the document turns on the visible light source to acquire a visible light image signal by the CCD. Then, the apparatus turns on the invisible light source to acquire an invisible light image signal by the CCD. After the invisible light image signal is acquired, the apparatus turns off the invisible light source, and turns on the visible light source regardless of whether to read the document.

Abstract: An electronic camera of the present invention includes an image pickup device, a positional data generating section, a memory, and an image processing section. The image pickup device includes a light-receiving plane photoelectrically converting a subject image. On the image pickup device any given partial image area is readable from a maximal image area. The positional data generating section generates positional data on the partial image area to the maximal image area. The memory holds a first edge enhancing filter used for data on the entire image and a second edge enhancing filter whose filter size is set smaller than that of the first edge enhancing filter. The image processing section performs, using the second edge enhancing filter, edge enhancement processing on data on a partial image extracted from the partial image area based on the positional data.

Abstract: An image reading apparatus that reads out an original document image synchronously with a frequency dispersion clock gained by modulating the frequency of a reference clock so as to be changed cyclically at a predetermined modulation period, comprising: a first signal generating section that generates a first signal which turns into assert state at a predetermined period; a second signal generating section that generates a second signal which turns into assert state at a period synchronous with the modulation period of the frequency dispersion clock; and a line scanning section that moves a scanning position on the original document image in an auxiliary scanning direction and scans the original document image in a main scanning direction perpendicular to the auxiliary scanning direction each time when both the first signal and the second signal turn to assert state and thereby reads the original document image and outputs an analog image signal.

Abstract: A noise reduction system comprises an inputting unit inputting image data, and a noise reduction unit performing a process for removing noise of the image data input by the inputting unit. The noise reduction unit includes a representative value calculating unit calculating a representative value from the level values of a plurality of pixels in a predetermined direction, which include an observed pixel of the input image data, a representative value selecting unit selecting one representative value according to a predetermined condition from among a plurality of representative values which are calculated by the representative value calculating unit and correspond to a plurality of directions, and a replacing unit replacing the level value of the observed pixel with the representative value selected by the representative value selecting unit.

Abstract: An efficient method and system for eliminating halftone screens from scanned documents while preserving the quality and sharpness of text and line-art is disclosed. The method and system utilizes one or more independent channels with different sensitivities (e.g., Max, High, and Low) to provide high quality frequency and magnitude estimation. The most sensitive channel (Max) derives the frequency estimate, and the remaining channels (e.g., High and Low) are combined to create the screen magnitude. The Max channel is the most sensitive and will usually report the existence of frequencies even when the screen is very weak. Therefore, the screen frequency must be additionally qualified by the screen magnitude. The screen magnitude can be interpreted as the level of confidence that the local neighborhood represents half-toned data.

Abstract: Disclosed is an adaptive channel estimator for improving a performance of a general channel estimator in a mobile communication system, and a method for controlling the same. The adaptive channel estimator further detects a noise level of a channel and a channel speed, and implements an optimum noise elimination filter on the basis of the detected noise level and channel speed. A comparison between mapping degrees predetermined by the detected noise level and channel speed allows an optimum noise elimination filter to be implemented, If such a channel estimator is implemented, then optimum packet data transmission is available for not only a low-speed channel but also a high-speed channel. A channel compensation caused by a difference between a spreading factor (SF) of a pilot channel and a spreading factor (SF) of a data channel can be compensated on the condition that a slope compensator executed by a SF ratio is controlled by a filter coefficient controller.

Abstract: A method for a multi-function scanner for scanning a document with a laser/anti-counterfeit mark includes the steps of: pre-scanning the document to obtain a preview image; recording a zone of the laser/anti-counterfeit mark selected by a user on the preview image as a marked zone; using a visible light source to scan the document so as to obtain a first image corresponding to the document excluding the marked zone; using an infrared right source to scan the document so as to obtain a second image corresponding to the marked zone; and combining the first image with the second image.

Abstract: A solid-state imaging apparatus includes: a pixel section where a plurality of pixels for effecting photoelectric conversion are two-dimensionally arranged, having an effective pixel section consisting of pixels for receiving object light and a reference pixel section consisting of pixels shielded from light; a first scanning circuit for sequentially setting to the pixel section the pixels to be read out a signal; a noise suppressing circuit for suppressing noise components of signals from the pixels based on a first control signal associated with sampling and holding of signals from the pixels and a second control signal associated with setting of clamping potential that are applied at respective predetermined timings; a second scanning circuit for sequentially reading signals of each pixel suppressed of the noise components; and a reference signal control section for applying the first and second control signals to the noise suppressing circuit so that it is brought into one or the other of a first conditio

Abstract: Spatial noise is reduced in an image having a plurality of pixels by detecting object boundaries and unstructured areas in the image and applying 3-tap high pass filters to each pixel in the image in at least four, but less than eight directions to determine the best direction for local low pass filtering. Low pass filtering is applied only along object boundaries and unstructured areas within the image so as to minimize the tendency to blur image edges. Using only four high pass filters to locate horizontal, vertical and diagonal image edges passing through the center of a 3×3 pixel array provides good results.

Abstract: In an image processing method for reducing an input image while preventing moire without deterioration of image quality, presence/absence of periodicity is detected for each pixel on the input image, and if there is periodicity, an image period is detected (S4). Sample points are sequentially extracted from the input image at prescribed sampling intervals (S5). A value is obtained by multiplying the image period by n (n is a natural number) that exceeds the sampling interval, to set a smoothing area. Pixels around a sample point is smoothed in the set smoothing area. The pixel value for a reduced image is obtained (S6). If there is an unprocessed sample point (NO at S8), the step goes back to S6, and the next sample point is subjected to a similar process. If the process is terminated for all the sample points (YES at S8), the reduced image is output.

Abstract: A method automatically corrects dust artifact within images acquired by a system including a digital acquisition device including a lens assembly. Multiple original digital images are acquired with the digital acquisition device. Probabilities that certain pixels correspond to dust artifact regions within the images are determined based at least in part on a comparison of suspected dust artifact regions within two or more of the images. Probable dust artifact regions are associated with extracted parameter values relating to the lens assembly when the images were acquired. A statistical dust map is formed including mapped dust regions based on the determining and associating. Pixels corresponding to correlated dust artifact regions are corrected within further digitally-acquired images based on the associated statistical dust map.

Abstract: A document reading device includes a document transport and, for reading a document image, an optical reader having a movable exposure which stops at a predetermined reading position and emits light onto the document. A guide member guides the document to the reading position to form a predetermined inclination angle with respect to a flat-plate face of a support, which supports the document being transported when it passes over the reading position. A transport path is formed with the support so that the document passing over the reading position is transported along the flat-plate face. A detection member detects a leading end position of the guide member, the predetermined reading position being set to within a predetermined distance in a transport direction from the leading end of the guide member, which is known beforehand to be stain-free.

Abstract: A device for obtaining graphical information from a single- or multi-page document printed on a hard media where reading out of the position of the document elements is performed by using a method of volumetric scanning of a document (even closed) is described. Processing of scanning results, comprises joining up the separate scanning layers scanning results, removing noise, correction of document image orientation, dividing information into portions relating to separate pages, is performed after reading the information. Then text information recognition contained in the graphical file is performed. Information may be read out by using methods of magnetic resonance scanning, supersonic scanning, X-ray scanning etc. The results of scanning in electronic form may be stored for further transmission thereof on a medium or via communication channels to a distant location for recognition.

Abstract: A streak detection method and system in a fixed imaging array digital scanning system obtains image data from each of the plurality of rows in the at least one full color spectrum channel set of rows of positionally discrete sensors and integrates this data to produce an estimate of image data recorded by at least one clear channel row of positionally discrete sensors. A clear channel error signal is generated by the comparison to alert the operator to the presence of non-image data. The clear channel error signal may be refined to through a low pass column filtering process in order to filter out potentially erroneous clear channel error resulting from thermal, mechanical or other noise sources unrelated to image scanning. Stationary obstructions in the field of view of the imaging array, or defects in one or more sensors in the imaging array, are detected through this comparison which would otherwise appear repeatedly reproduced as streaks or lines in the reproduced output image.

Abstract: A blurred image generating section generates a plurality of blurred images Sm (where m=1 to n and n?2) different in frequency response characteristic from one another, based on an original image S0. A band-limited image generating section generates a plurality of band-limited images Tm by performing a subtraction between images of adjacent frequency bands, employing the original image S0 and each of the blurred images Sm. A wrinkle component extraction section extracts converted images, obtained by performing nonlinear conversion on each of the band-limited images Tm, as wrinkle components Qm contained in the different frequency bands. A wrinkle-component elimination section eliminates wrinkle components of the original image S0 by subtracting from the original image S0 a value obtained by multiplying a subtraction coefficient ? (which is determined according to the pixel value Y0 of the original image S0) and the sum of the wrinkle components Qm together.

Abstract: When an optical image obtained by an optical scanning unit of optically scanning an original sheet automatically fed by an original sheet feeder is read, it is discriminated in units of pixel whether or not dirt or scratch attached to a running reading glass plate is present. Moreover, the number of the dirt and the width of the dirt are detected, and an image reading position which does not come under the influence of the dirt as much as possible is set based on the detected number of the dirt and the detected width of the dirt even when the dirt is detected at all the reading positions.

Abstract: A method to reduce coding artifacts within a discrete decoded picture includes a spatial and/or temporal filtering with respective filter characteristics dependent on an image quality value (Q). Preferably, the spatial filtering includes a deblocking filtering, wherein the deblocking filter operation decreases with an increasing image quality value (Q) and/or the deblocking filtering chooses an image quality value (Q) dependent weighting function for a pixel to be filtered according to an activity of both blocks to which common border said pixel belongs.

Abstract: A de-noising algorithm that obtains an estimate of a noise-free portion of a noise-containing digital signal by applying a set of M linear transforms to the noise-containing digital signal, determining M initial de-noised estimates of each digital element of the digital signal, deriving a combination of weight factors for the M initial de-noised estimates of each digital element by formulating the combination as a linear estimation problem and solving it for the individual weight factors, and formulating a final de-noised estimate of each digital element based on the corresponding M initial de-noised estimates and the combination of weight factors. The combination of weight factors is an optimal combination that is derived such that a conditional mean squared error with respect to the initial de-noised estimates is minimized. The optimal determination is further determined based on a scaling factor that removes explicit dependence to noise variance and on one of several matrices.

Abstract: An apparatus has an image sensing device, and a signal processing device for performing a first image sensing operation for making the image sensing device perform an image sensing operation in an exposure state to obtain a sensed image signal, and a second image sensing operation for making the image sensing device perform an image sensing operation in a non-exposure state to obtain a sensed image signal, and processing the sensed image signal obtained by the first image sensing operation by the sensed image signal obtained by the second image sensing operation. The signal processing device determines in accordance with the image sensing time of the first image sensing operation whether or not the second image sensing operation is performed.