Abstract: A system and method for detecting human skin tone in one or more images. The system includes an image processing module configured to receive an image and provide contrast enhancement of the image so as to compensate for background illumination in the image. The image processing module is further configured to detect and identify regions of the contrast-enhanced image containing human skin tone based, at least in part, on the utilization of multiple color spaces and adaptively generated thresholds for each color space. A system and method consistent with the present disclosure is configure to provide accurate detection of human skin tone while accounting for variations in skin appearance due to a variety of factors, including background illumination and objects.

Abstract: System and methods for gamut bounded saturation adaptive color enhancement are provided. Color enhancement incorporating gamut bounded saturation enhances colors of an pixel from a source color gamut such that the resulting color is within a target color gamut. This resulting color may, for example, take advantage of an expanded target color gamut of a display. Gamut bounded saturation may be implemented independently or in combination with RGB bounded saturation.

Abstract: A method for enhancing a radiographic image. The method includes obtaining image data for the radiographic image, generating conditioned image data by increasing differences between neighboring portions of at least a relatively uniform area of the radiographic image, generating an enhanced image by applying contrast limited adaptive histogram equalization to the conditioned image data, applying interpolation to the enhanced image, and displaying, storing, or transmitting the enhanced image.

Abstract: An example method includes interpreting compressed source data to produce a set of representative colors and modulation data. Portions of the modulation data are interpreted as a plurality of vectors. Each vector pertains to a respective region of the image, which has multiple portions, each with elements. Modulation data is interpreted to include vector modifier data. A respective color for each element within a first portion of the region is determined from the set of representative colors, which are combined according to a selected vector (can be a selection made from a subset of the plurality). Colors for elements in other portions of the region are determined by selecting a vector, modifying the vector according to vector modifier data, and applying the modified vector with the set of representative colors to produce colors for elements in the region. Aspects include systems and methods for source data compression and image reconstruction.

Abstract: An object area detection means detects an object area which is an area to be subjected to image processing from an input image. A reflection component reconstruction means calculates color information of the object area and a perfect diffusion component, which is a low-frequency component of the object area, and reconstructs a surface reflection component based on the color information and the low-frequency component. A surface reflection component correction means corrects the reconstructed surface reflection component according to a reference surface reflection component that is the surface reflection component set in advance according to the object area. A reproduced color calculation means calculates a reproduced color that is a color obtained by correcting each pixel included in the input image by using the perfect diffusion component and the corrected surface reflection component and generates an output image based on the reproduced color.

Abstract: An image reading apparatus includes a light source device, a reader, a plurality of strip-shaped density reference members, and a shading corrector. The plurality of strip-shaped density reference members that extend along main scanning direction. The plurality of strip-shaped density reference members are separately disposed in at least three positions including an upstream end portion, a center portion, and a downstream end portion in the moving direction of the sub scanning direction within a readable area of the reader. The shading corrector is configured to calculate shading correction data using density distribution data obtained by reading the plurality of strip-shaped density reference members with the reader and correct image data of the printed document on a pixel to pixel basis, based on the shading correction data.

Abstract: A system and method identify and display random noise in three dimensional (3-D) seismic data utilizing a 3-D operator to reduce the effects of seismic structure on noise identification. The 3-D operator is derived using statements of required performance in 3-D. The 3-D operator is applied on a pixel-by-pixel basis to each of the pixels in the 3-D post-stacked data to display images in a 3-D display or to output an estimate of noise that is substantially independent of the image structure. The resulting display is generated in colors to indicate noise amplitude to facilitate location of noisy regions in the original display.

Abstract: A method of providing range measurements for use with a vehicle, the method comprising the steps of: a) visually sensing (2) the area adjacent the vehicle to produce visual sense data (22); b) range sensing (26) objects around the vehicle to produce range sense data; c) combining the visual sense data and the range sense data to produce, with respect to the vehicle, an estimate of ranges to the objects around the vehicle (28). The estimate of ranges to the objects around the vehicle may be displayed (29) to a driver.

Abstract: The invention relates to a method for generating images having a reduced error rate, high resolution and improved contrast from image sequences containing images having lower resolutions, which can be obtained from an image sensor having adjustable recording parameters. According to the invention, the image sequences of the images (K, R) having low resolutions are subjected to a combination of super-resolution processing (SR) and high dynamic range reconstruction processing (HDR) in order to obtain images having a reduced error rate, high resolution and improved contrast on the basis of redundant and complementary image information contained in the images having low resolution.

Abstract: A plurality of images are used as input images. On the basis of a degree of similarity to an input image group and an evaluation of the quantity of edges of an overall image, a new image is generated. An image processing method may comprise calculating a specified color characteristic degree indicating a degree of similarity between a pixel color of a generated image predicted from the input image group and a specified color that has been specified beforehand, and for, on the basis of the specified color characteristic degree, modifying a weight corresponding to the edge quantity of each pixel within the generated image, and generating an image wherein the manner of reproduction of edges of areas of the specified color differs from other regions.

Abstract: Systems and methods are described for determining manipulation history among a plurality of images. The described techniques include selecting a pair of images from the plurality of images, detecting one or more manipulations operable to transform one of the images to the other, and based on the manipulations detected, determining a parent-child relationship between the pair or pairs of images. The described techniques can further include repeating the selecting two images, detecting manipulations, and determining the parent-child relationship for each pairs of images in the plurality of images, constructing a visual migration map for the images, and presenting the visual migration map in a user readable format.

Abstract: A noise reduction section includes: a correlation detector configured to detect correlations between corresponding pixels between first and second image signals which are obtained from an identical image, and output degrees of correlation based on the detected correlations; an addition ratio determining section configured to determine addition ratios of the corresponding pixels between the first and second image signals based on the degrees of correlation, where the addition ratios are used in weighted addition averaging processes; and a weighted addition averaging section configured to perform, based on the addition ratios, the weighted addition averaging processes on the corresponding pixels to generate an output image signal, wherein when each of the degrees of correlation is relatively high, the addition ratio determining section provides a relatively high proportion of the pixel of the second image signal in the addition ratio.

Abstract: A method and system operative to process color image data are disclosed. In one embodiment, the method can comprise the steps of receiving color image data, determining the color ranges to be applied to the color image data, assigning each of the pixel positions in the image data a color range, assigning a different spatial binary pattern to each color range, and assigning each of the pixel positions a binary output pixel value that corresponds to the spatial binary pattern assigned to the color range assigned to that pixel position. The resulting binary image data can be written to a file for subsequent storage, transmission, processing, or retrieval and rendering. In other embodiments, a system can be made operative to accomplish the same.

Abstract: An image processing device can explicitly distinguish cells to be observed from cells other than those to be observed with a simple configuration. To this end, the image processing device includes a color information obtaining part obtaining at least hue from color information of each pixel of a color image, a detecting part detecting a mode value of the hue on a color space, a range setting part setting a predetermined range on the color space including the mode value of the hue detected by the detecting part as a target range, a changing part changing hue of a pixel included in the target range by virtually performing extension on the target range, and an information converting part converting color information of a pixel having hue not included in the target range into color information indicative of an achromatic color.

Abstract: A method of calculating a correction value used when signal value correction is performed with respect to an image signal supplied to a display panel includes setting a target luminance value, which is not uniform in an overall surface of the display panel, as a target luminance value of one image signal value such that at least a portion of a distribution of target luminance values at each plane position of the display panel becomes a curved distribution, and calculating a correction value at each plane position of the display panel using luminance observed at each plane position of the display panel when one image signal value is given to the overall surface of the display panel and the target luminance value at each plane position of the display panel.

Abstract: An image processing method is provided, which includes a step of separating an object image into an object region and a background region, a step of calculating a gray scale value of an average color of the object region, a step of calculating a gray scale value of an inversion color of the object region by using the gray scale value of the average color, and a step of calculating a gray scale value of a background region of a processed image by using the gray scale value of the inversion color and a gray scale value of the background region of the object image.

Abstract: A region growing algorithm for controlling leakage is presented including a processor configured to select a starting point for segmentation of data, initiate a propagation process by designating adjacent voxels around the starting point, determine whether any new voxels are segmented, count and analyze the segmented new voxels to determine leakage levels, and identify and record segmented new voxels from a previous iteration when the leakage levels exceed a predetermined threshold. The processor is further configured to perform labeling of the segmented new voxels of the previous iteration, select the segmented new voxels from the previous iteration when the leakage levels fall below the predetermined threshold, and create a voxel list based on acceptable segmented voxels found in the previous iteration.

Abstract: An image processing device includes: a first band limiting unit that reduces noise included in an input image; and a restoring unit, wherein the restoring unit has a difference calculating unit that calculates a difference between the input image and a noise-reduced image, a predicted noise obtaining unit that obtains a predicted noise amount to be included in the input image, a correction signal generating unit that generates a correction signal for correcting the noise-reduced image and controlling an absolute value of the difference between the input image and the noise-reduced image within a range of the predicted noise amount, and an image synthesizing unit that corrects the noise-reduced image based on the correction signal.

Abstract: A method of testing analog and digital paths of a pixel in a row of an imager, includes the following steps: (a) injecting first and second charges into the analog path of the pixel, wherein the first charge is in response to a light exposure, and the second charge is in response to a built-in test; (b) sampling the first and second charges to form an image signal level and a test signal level, respectively; and (c) converting, by an analog-to-digital converter (ADC), the image signal level and the test signal level to form image data and test data, respectively. The method then validates the image data based on the test data.

Abstract: An image processing apparatus includes an obtainment section to obtain a face image; an area specifying section to specify a set of a plurality of corresponding areas in the face image obtained by the obtainment section; and a correction section to generate a face image in which one area of the plurality of corresponding areas of the face image is used as a reference to correct another area.

Abstract: A first color component of a pixel or scene entity is modified using a color correction curve defined at least partly by a second color component of this pixel or entity. Each pixel or entity has its own separate color correction curve, independent of the color correction curves of other pixels or entities. The saturation value of a pixel or scene entity may be modified based on its luminance value. The luminance value determines a saturation gamma function curve, mapping the original saturation value of a pixel or entity to a new saturation value. The unilluminated color of a pixel or of an illuminated entity in a scene being rendered may also be taken into account. This output color may be stored in the appropriate pixel of an image or combined with colors from other portions of the scene being rendered.

Abstract: Automatic generation of a mosaic comprising a plurality of geospatial images. An embodiment of the automatic mosaic generation may include automated source image selection that includes comparison of source images to base layer image to determine radiometric similar source images. Additionally, an embodiment of an automatic cutline generator may be provided to automatically determine a cutline when merging two images such that radiometric differences between the images along the cutline are reduced. In this regard, less perceivable outlines may be provided. Further still, an embodiment of a radiometric normalization module may be provided that may determine radiometric adjustments to source images to match certain properties of the base layer image. In some embodiments, when processing source images, the source images may be downsampled during a portion of the processing to reduce computational overhead. Additionally, some highly parallel computations may be performed by a GPU to further enhance performance.

Abstract: An indentation hardness test system is provided that includes: a frame including an attached indenter; a movable stage for receiving a part attached to the frame; a camera; a display; a processor; and a memory subsystem. The processor performs the steps of: (a) capturing images of different portions of the part; (b) for each image, computing an average intensity; (c) computing an average intensity across all images; (d) for each pixel, computing PixelAverageDeltan(x,y) as a function of the raw pixel data and the average pixel intensity of the image frame; (e) for each pixel, computing a correction factor using the average intensity across all images and PixelAverageDeltan(x,y); (f) performing shading correction by adjusting the raw pixel values by corresponding correction factors; and (g) generating a composite image of the part. Steps (b)-(e) may be performed on moving images while not including stationary images in the computations of those steps.

Abstract: Techniques for making, using and updating a Modeled Atmospheric Correction Object (MACO) cluster and the MACO sites that are selected from within a given MACO cluster. The MACO construct is a novel application of a Model of Reality (MOR) that provides synthetic ground truth essential to converting imagery from top-of-the-atmosphere radiance to surface reflectance given a variety of spatial, spectral and radiance effects involving non-uniform distributions of opaque clouds, cirrus clouds, aerosols, water vapor, surface ice, surface snow, shadows and bidirectional reflectance distribution function (BRDF) effects.

Abstract: A method for selecting an optimum subset of images from a larger set of images for optimal HDR image creation. For each of the set of images, an exposure quality map is computed by assigning, to each pixel of the image, an exposure quality value based on the pixel brightness value of that pixel. A suitable exposure quality function, typically reflecting the properties of the imaging device, is used for this purpose. Then, for each possible subset of images, the exposure quality maps for the images in the subset are combined using a max operation to generate a combined exposure quality map for the subset. An average pixel value of the combined exposure quality map of the subset is then calculated and serves as a quality score. The subset of images processing the highest quality score are used to generate the HDR image.

Abstract: An image processing apparatus includes the following elements. A receiving device receives an image. An extracting device extracts regions from the image received by the receiving device. A selecting device selects a region from among the regions extracted by the extracting device in accordance with a predetermined rule. A measuring device measures luminance values of pixels contained in the region selected by the selecting device. An estimating device estimates a function representing a degree of fog in the image received by the receiving device from the luminance values of the pixels measured by the measuring device. An eliminating device eliminates fog from the image received by the receiving device on the basis of the function estimated by the estimating device.

Abstract: A method of compressing and decompressing digital data that is especially suitable for halftoned image data in which every bit represents the marking of a receiving material by ink or toner is provided. The method is lossless and balances the use of memory, the processing time, the compression factor and the cost of hardware resources. The recurrence of data in halftoned images on which the smaller data size of the compressed data is based, is caused by the use of a halftone dither matrix. Various halftone dither matrices may be used in the halftoned image. The method is adapted to employ the characteristics of a specific halftone dither matrix by applying a dynamic set of offset values, in which an offset value represents a number of words between the current word of digital data and an identical, previously processed word.

Abstract: A Method for inspecting flat objects, especially wafers, with an object surface, comprises the steps of: scanning a digital image with a plurality of image points of said object surface with color- or grey values for each of said image points; detecting defects on said object surface by comparing said scanned digital image to a digital reference image; defining and selecting corresponding portions in said scanned digital image and in the digital reference image; determining a representative color- or grey value for each of said selected portions; calculating a compare value from said representative color- or grey value of said scanned digital image of a portion and a representative color- or grey value of said digital reference image of the same portion; and correcting each image point of said scanned digital image with a correction value determined from said compare value of step (e).

Abstract: An endoscope 100 includes a first light source 45 that emits white illumination light, a second light source 47 that emits narrow-band light and an imaging section that has an imaging device 21 having plural detection pixels and images a region to be observed. The imaging section is caused to output a captured image signal including both a return light component of the white illumination light from the region to be observed by and a return light component of the narrow-band light the white illumination light. From the captured image signal, the return light component of the narrow-band light is selectively extracted, and a brightness level of the extracted return light component of the narrow-band light is changed by changing a light amount of light emitted from the second light source 47.

Abstract: A video image capture component includes a light source operable in a first spectrum, a first image detector operable in the first spectrum, a second light source operable in a second spectrum, and a second image detector operable in the second spectrum. A filtering component generates a combination image by filtering a first image obtained by the first image detector with a high-contrast filter, resulting in a high-contrast image, and masking a second image obtained by the second image detector using the high-contrast image. A compositing component creates a composite image from the combination image and a selected image. A display component displays the composite image. Alternative systems and methods for creating a combination image include techniques involving thermal imaging, laser detection, and narrow band frequency detection.

Abstract: An image recovery method is disclosed for eliminating an effect of an environmental medium. The image recovery method includes receiving a captured image affected by the environmental medium, defining a respective local window with each pixel located at a center of the respective local window, and under an assumption that original radiance of all pixels within the respective local window in the captured image are identical, performing a minimization calculation for each local window, to obtain a corresponding transmission of each pixel in the captured image.

Abstract: An apparatus, computer program product, and method for reducing persistent shadows within an image. The apparatus includes a camera configured to generate frames of the image. The apparatus also includes a computer processor. The computer processor calculates the average normalized brightness for each pixel in the image and adjusts the brightness of each pixel with the average normalized brightness.

Abstract: A fluoroscopy apparatus including: an illumination unit having a light source radiating illumination light and excitation light onto an observation target, a fluorescence-imaging unit acquiring a fluorescence image by imaging fluorescence generated at the observation target by the excitation light, a white-light-imaging unit acquiring a reference image by imaging light returning from the observation target by the illumination light, and an image-correction unit obtaining a correction fluorescence image by raising the luminance value of the fluorescence image to the power of a reciprocal of a first and second exponent obtained by a power approximation of a distance characteristic of luminance versus observation distance, for the fluorescence image, and that obtains a corrected fluorescence image by dividing the correction fluorescence image by the correction reference image.

Abstract: Systems, including apparatus and methods, for obtaining and/or correcting images, particularly from atmospheric and/or other distortions. These corrections may involve, among others, collecting two or more sets of image data corresponding to images of the same scene in different wavelength regimes, and using correlations between wavelength and expected distortion to distinguish apparent image motion due to distortion from apparent image motion due to object or scene motion. These systems may be useful in any suitable imaging context, including navigation, targeting, search and rescue, law enforcement, commercial video cameras and/or surveillance, among others.

Abstract: There is provided an output device including an inputting unit, an extracting unit, a calculating unit, an adjusting unit and an outputting unit. The inputting unit is configured to input an image file representing a motion image. The extracting unit is configured to extract, from the image file, a first frame image and at least one neighboring frame image that is chronologically continuous with the first frame image. The calculating unit is configured to calculate a total adjustment parameter for adjusting the first frame image based on the first frame image and the at least one neighboring frame image. The adjusting unit is configured to adjust the first frame image using the total adjustment parameter to generate a first adjusted output image. The outputting unit is configured to output the first adjusted output image.

Abstract: It is determined whether or not an input image is an image converted from an image with a relatively low resolution based on one frame of an image. A resolution determination device includes: an edge strength calculator configured to obtain an edge strength of a pixel included in an input image based on luminance of the pixel and luminance of a pixel adjacent to the pixel, for each of a plurality of pixels included in the input image; and a resolution determiner configured to determine whether or not the input image is an image upconverted from an image with a predetermined resolution or less, based on distribution of the edge strengths.

Abstract: Systems, methods and apparatus for image processing by classifying pixels are described. In some systems, an exposure control operation is performed according to the pixel classifications. In some cases, the pixels are classified according to a predetermined segmentation of a color space, based on predicted sensor responses.

Abstract: A method of fusing two images includes adjusting contrast of (a) a visual image and (b) a thermal image. Also included is modifying the adjusted contrast of the thermal image to form output brightness levels, by using a transformation curve, and then displaying both (a) the brightness levels of the thermal image and (b) the adjusted contrast of the visual image. Modifying the adjusted contrast of the thermal image includes using a V-curve as the transformation curve, in which the V-curve includes similar maximum output brightness levels at the coldest and hottest relative temperatures, respectively. The V-curve also includes a minimum output brightness level at a midpoint between the coldest and hottest relative temperatures. Furthermore, the method assigns different hues to the intensity values of the thermal image, ranging from coldest to hottest relative temperatures.

Abstract: Some embodiments provide a program that performs a color balance operation. The program identifies an image that includes several pixels. Each pixel includes a luma component value and chroma component values. The program analyzes the luma component values of the pixels in the image to identify several luma ranges. The program determines, for each luma range in the several luma ranges, a set of transforms for modifying chroma component values of pixels in the image in order to remove a color cast from the image. The program applies the sets of transforms to the image to remove the color casts from the image.

Abstract: A patient monitoring/defibrillation instrument displays patient vital signs in numeric form or as graphical waveform traces. Under normal room lighting conditions the numeric and waveform information is displayed in color against a black or gray background. When the patient monitor is operated outside or in bright light, the user has the option to select a color map for display of the patient vital signs information in a highly contrasting manner such as black numeric or waveform information against a bright background such as yellow. The high contrast display, while being objectionable in most indoor settings, has been found to comfortably and effectively display the monitored information in sunlight without the need to increase power to the display.

Abstract: A method of processing a digital image, said image comprising a plurality of pixels, the method comprising a computation step (S1) wherein a histogram of the distribution of the number of pixels of the image as a function of their luminance is computed, a step (S2) for lightening the image based on said histogram comprising a subdivision (S20) of the pixels of the image into a first set of pixels having luminance values between a low threshold and a high threshold and into a second set of pixels having luminance values greater than said high threshold, a first luminance processing operation (S21) on the pixels of the first set of pixels and a second luminance processing operation (S22) on the pixels of the second set of pixels, the two luminance processing operations (S21, S22) being different, the first processing operation (S21) comprising an increase in the luminance of the pixels of the image.

Abstract: A method and apparatus for correcting for vignetting include associating each pixel in the two-dimensional array with a pair of polar coordinates referenced to a preselected origin pixel and partitioning the two-dimensional array of image pixels into a plurality of sectors. For each sector, the method includes computing an average R value, an average G value and an average B value; converting the average R value, the average G value and the average B value for each sector to logarithm space; comparing color gradients along a radial sector line to a gradient threshold; selecting gradients that do not exceed the threshold; using the selected gradients, estimating parameters of a model of a lens which produced the image; and, using the parameters, updating the model of the lens and correcting the image.

Abstract: Disclosed herein are systems and methods for automated MRI. According to an aspect, a method for MRI includes receiving a plurality of MRI data signals representative of a region including a volume of interest. The method also includes determining at least one subvolume within the VOI. Further, the method includes determining a state of the at least one subvolume. The method also includes implementing a predetermined action based on the predetermined state.

Abstract: Methods and apparatus according to various aspects take as input image data in a lower-dynamic-range (LDR) format and produce as output enhanced image data having a dynamic range greater than that of the input image data (i.e. higher-dynamic range (HDR) image data). In some embodiments, the methods are applied to video data and are performed in real-time (i.e. processing of video frames to enhance the dynamic range of the video frames is completed at least on average at the frame rate of the video signal).

Abstract: Systems and methods for texture processing are presented. In one embodiment a texture method includes creating a sparse texture residency translation map; performing a probe process utilizing the sparse texture residency translation map information to return a finest LOD that contains the texels for a texture lookup operation; and performing the texture lookup operation utilizing the finest LOD. In one exemplary implementation, the finest LOD is utilized as a minimum LOD clamp during the texture lookup operation. A finest LOD number indicates a minimum resident LOD and a sparse texture residency translation map includes one finest LOD number per tile of a sparse texture. The sparse texture residency translation can indicate a minimum resident LOD.

Abstract: This disclosure pertains to apparatuses, methods, and computer readable media for red-eye removal techniques using multiple recognition channels. In the following examples, red, golden, and white recognition channels are used. A recognition channel is the monochrome extraction from a color photograph in a manner designed to make one kind of red-eye artifact glow with maximum contrast. Once the red-eye artifact has been characterized by, e.g., size and location, the techniques disclosed herein may then discern whether the red-eye artifact is, for example, a red-, golden-, or white-eye case by examining the configuration and characteristics of prominence bitmasks created for the various recognition channels. Once the type of red-eye case has been discerned, the techniques disclosed herein may then replace the artifact with a photographically reasonable result based on the type of red-eye case being repaired. Specular reflection may also be re-added to the photograph.

Abstract: A driver assistance system for a vehicle includes a forward facing camera and a processor operable to process image data captured by the camera. Responsive to processing of captured image data, the driver assistance system is operable to determine a lane along which the vehicle is traveling and to detect oncoming vehicles approaching the vehicle in another lane that is to the right or left of the determined lane along which the vehicle is traveling. The driver assistance system is operable to control, at least in part, a light beam emanating from a headlamp of the vehicle and adjusts the light beam emanating from the headlamp to limit directing beam light towards the eyes of a driver of the detected oncoming vehicle. Responsive to processing of captured image data, the driver assistance system is operable to provide lane departure warning to a driver of the vehicle.

Abstract: A method of spectral-spatial-temporal image detection is disclosed. In one embodiment, a spectrally differenced image is obtained by computing a difference of at least two intensity values in at least two spectral bands of an image. Further, a spatially filtered spectral image is obtained by applying a spatial median filter to the obtained spectrally differenced image. Furthermore, a temporal image is obtained by determining a temporal pixel value difference using a computed predictive frame difference. In addition, a spectral-spatial-temporal filtered image for detection is obtained by using the obtained spatially filtered spectral image and the temporal image.

Abstract: A method is provided for scaling an image taken at a given exposure time to a selected exposure time. The method generally comprises: determining a dark pixel intensity of an imaging device; acquiring a first image at a given exposure time; and adjusting a pixel intensity of one or more pixels in the first image, based at least in part on the dark pixel intensity, for a second exposure time that is different from the given exposure time.

Abstract: A magnified image is improved by integrating the wavelength specific component into that image. A magnified images obtained, and at least one wavelength specific component images also obtained. The different images are converted in color space, and different channels, indicative of the different parts of the image shows, are also obtained. For example, the image may be converted to an L*a*b* color space, and the luminance channel of the wavelength specific component may be used to enhance or replace the luminance channel of the magnified image.