Abstract: Techniques are described to combine image data from multiple images with different exposures into a relatively high dynamic range image. A first image of a scene may be generated with a first operational mode of an image processing system. A second image of the scene may be generated with a second different operational mode of the image processing system. The first image may be of a first spatial resolution, while the second image may be of a second spatial resolution. For example, the first spatial resolution may be higher than the second spatial resolution. The first image and the second image may be combined into an output image of the scene. The output image may be of a higher dynamic range than either of the first image and the second image and may be of a spatial resolution higher than the second spatial resolution.

Abstract: Provided is an image generation system and method, more particularly, an image generation system and method which can generate a high dynamic range image from a plurality of images acquired in a single short exposure. The image generation system To includes an image generation system having an image acquisition unit to acquire an image, an image generation unit to generate, from the acquired image, a plurality of images with different resolution and brightness, and an image synthesis unit to synthesize the generated images.

Abstract: An image capturing apparatus and a control method capable of obtaining an image with a wide dynamic range, without using a special image sensor. An amount of dynamic range enhancement for lessening an amount of blown-out highlights of an image is determined based on the amount of blown-out highlights. An image with enhanced dynamic range is then obtained, by performing image capture at a sensitivity that has been lessened based on the amount of dynamic range enhancement, and correcting a drop in brightness of the captured image due to the lessened sensitivity.

Abstract: In an image capturing apparatus, a subject image is converted into an image signal, which undergoes automatic correction processing including white balance correction processing, and further undergoes image quality change processing. A first evaluation value indicating a largest value of an R signal, a G signal, and a B signal of the image signal undergone the image quality change processing and a second evaluation value indicating a luminance of the image signal undergone the image quality change processing are detected. A control evaluation value is calculated using weighted average of the first evaluation value and the second evaluation value according to at least one of an amount of image quality changing effect due to the image quality change processing and a reliability of the automatic correction processing, and exposure control is performed based on the control evaluation value.

Abstract: An image pickup apparatus capable of increasing the dynamic range and performing high-frame rate imaging. The image pickup apparatus includes a pixel section formed by arranging a plurality of pixels each including different types of pixels different in sensitivity to light, in a two-dimensional matrix form. Different types of ADCs perform analog-to-digital conversion of signals read out from the high-sensitivity pixels and low-sensitivity pixels in parallel and hold results in respective counter latch circuits. The pixel section has an interconnection layer including a plurality of interconnections for transferring the signals. One interconnection is used as a vertical read-out line for transferring signals from the low-sensitivity pixels, and another interconnection is used as a vertical read-out line for transferring signals from the high-sensitivity pixels.

Abstract: An image sensor, an image processing apparatus including the same and an interpolation method of the image processing apparatus are provided. The image sensor includes a plurality of pixels that include a low-luminance pixel including a first photoelectric conversion device that accumulates a charge less than a predetermined reference value and a high-luminance pixel including a second photoelectric conversion device that accumulates a charge more than the predetermined reference value. Interpolation is carried out giving more weight to the low-luminance pixel at low luminance and giving more weight to the high-luminance pixel at high luminance, so that a higher SNR is obtained.

Abstract: An image processing apparatus includes a calculation unit configured to calculate a first gain for adjusting brightness of a first image and a second image based on the first image captured at a first exposure amount and the second image captured at a second exposure amount, a division unit configured to divide the first gain into a second gain which changes according to a position in an image and a third gain which does not change according to a position in an image, a first gain correction unit configured to perform gain correction on the second image with the second gain, and a second gain correction unit configured to perform gain correction on the second image with the third gain.

Abstract: Apparatus and methods are provided for obtaining high dynamic range images using a low dynamic range image sensor. The scene is exposed to the image sensor in a spatially varying manner. A variable-transmittance mask, which is interposed between the scene and the image sensor, imposes a spatially varying attenuation on the scene light incident on the image sensor. The mask includes light transmitting cells whose transmittance is controlled by application of suitable control signals. The mask is configured to generate a spatially varying light attenuation pattern across the image sensor. The image frame sensed by the image sensor is normalized with respect to the spatially varying light attenuation pattern. The normalized image data can be interpolated to account for image sensor pixels that are either under or over exposed to enhance the dynamic range of the image sensor.

Abstract: An apparatus for imaging an object has an image sensor that comprises a plurality of pixels. The plurality of pixels is matrix-arrayed along vertical and horizontal directions. The apparatus also has an image sensor driver that drives the image sensor, and the image sensor driver is capable of reading image-pixel signals of neighboring pixels among the plurality of pixels while mixing the image-pixel signals. The apparatus also has a pixel addition setting processor that sets the number of pixel addition with respect to at least one of at least one row and at least one column. The pixel addition setting processor sets different numbers of pixel addition to different pixel areas. The image sensor driver reads the image-pixel signals in response to the set number of pixel addition.

Abstract: The invention provides a method for transforming an image from a Low Dynamic Range (LDR) image obtained with a given camera to a High Dynamic Range (HDR) image, the method comprising: obtaining the exposure-pixel response curve (21) for said given camera converting the LDR image to HSB color space arrays (22), said HSB color space arrays including a Hue array, a Saturation array and a Brightness array; and determining a Radiance array (23, 24) by inverse mapping each pixel in said Brightness array using the inverse of the exposure-pixel response curve (f?1).

Abstract: An imaging device and method of imaging an object is disclosed. The device includes a two-dimensional focal plane including a plurality of rows of pixels. The pixel is configured to measure an intensity of light directed onto the pixel using a gain parameter. A gain adjuster adjusts the gain parameter for a selected row of pixels of the focal plane array independently of a gain parameter of another row of pixels.

Abstract: An image pickup apparatus which is capable of accurately compensating for noise even when images are continuously taken at varying exposures. First and second image signals corresponding to the first and second exposures are output. The first and second image signals are subjected to a noise compensation process and then synthesized together to obtain a composite image signal. Data obtained in the first and second image signals when the noise compensation process was carried out on the first and second image signal is inherited, and a noise compensation process on the next first and second signals is carried out based on the data.

Abstract: According to one embodiment, a camera module has an exposure control unit. When an exposure error has reached within a coring range by first exposure control, the exposure control unit switches exposure control from the first exposure control to second exposure control. The exposure error shows a deviation of an exposure evaluation value to an exposure target value. In the second exposure control, an exposure change amount is reduced than at the time of the first exposure control. When the exposure error has reached a zero level by the second exposure control, the exposure control unit stops the exposure control.

Abstract: An image capturing apparatus determines a scene of a captured image, and, depending on the scene determination result, performs image capture with an expanded dynamic range, or performs a dynamic range contraction process based on the captured image. In the case of executing the dynamic range expansion process, the image capturing apparatus performs image capture at a decreased ISO speed, and performs tone correction for compensating the decrease in ISO speed with respect to the captured image. The image capturing apparatus is thereby capable of performing image capture with a dynamic range that takes into consideration the subject and the scene.

Abstract: Electronic devices may have camera modules that include an image sensor and processing circuitry. The image sensor may capture an interleaved image having rows of long-exposure pixel values that are interleaved with rows of short-exposure pixel values. The image sensor may separate the interleaved image into first and second images each having empty image pixel values. The processing circuitry may generate interpolated long-exposure and interpolated short-exposure images by generating chroma-filtered interpolated pixel values for the empty pixel values in the first and second images. The processing circuitry may perform interpolation operations along one or more directions for the empty image pixels based on whether the empty image pixels are within a texture area or on a dominant edge of the captured image. The processing circuitry may combine the interpolated long-exposure image and the interpolated short-exposure image to generate a high-dynamic-range image.

Abstract: Apparatus and method for realizing a processing with which a pixel gravity center control can be conducted when a pixel number reduction image is generated in an image pickup apparatus. A pixel unit configured to output a pixel addition signal obtained by adding output pixel signals from pixels having different sensitivities to each other and a pixel information synthesis unit configured to execute a weighted addition processing of multiplying plural pixel addition signals output from the pixel unit by a previously set gain and calculate a configuration pixel value of a pixel number reduction image where a total number of pixels is lower than a number of pixels of the pixel unit are provided.

Abstract: A method, system and reference target for estimating spectral data on a selected one of three spectral information types is disclosed. Spectral information types comprise illumination of a scene, spectral sensitivity of an imager imaging the scene and reflectance of a surface in the scene. The method comprises obtaining a ranking order for plural sensor responses produced by the imager, each sensor responses being produced from a reference target in the scene, obtaining, from an alternate source, data on the other two spectral information types, determining a set of constraints, the set including, for each sequential pair combination of sensor responses when taken in said ranking order, a constraint determined in dependence on the ranking and on the other two spectral information types for the respective sensor responses and, in dependence on the ranking order and on the set of constraints, determining said spectral data that optimally satisfies said constraints.

Abstract: An image processing apparatus for generating a high dynamic range image using a plurality of images obtained by capturing images of a same object with different exposure values, has: an input unit for inputting a correctly exposed image generated with correct exposure and an incorrectly exposed image generated with exposure other than the correct exposure; a filter unit for performing low pass filter processing on the incorrectly exposed image; and a composition unit for generating a high dynamic range image by composing an output image of the filter unit with the correctly exposed image.

Abstract: The invention relates to a method for controlling a light-sensitive device comprising a matrix of light-sensitive points arranged into lines and columns. The invention can essentially but not exclusively be used in light-sensitive devices used for detecting X-ray images. The method includes a step (E2) of acquiring an image during which each light-sensitive point can accumulate a charge, and a step (E3) of reading said image. The reading step (E3) comprises a preliminary sub-step (E31) of converting the charges accumulated at the different light-sensitive points into analog signals representative of said charges, and a sub-step (E32) of processing the analog signals in order to obtain a digital image.

Abstract: A method and apparatus for increasing a dynamic range of an image by using a first electronic shutter and a second electronic shutter of a camera is provided. The method includes initiating exposure of an image sensor by moving a first electronic front curtain according to a first control pulse signal of the first electronic shutter; moving a second electronic front curtain with respect to at least one pixel of the image sensor according to a second control pulse signal of the second electronic shutter; blocking the exposure of the image sensor by moving a mechanical rear curtain included in the camera; and acquiring, after blocking the exposure, a long exposure image using the first electronic front curtain and a short exposure image using the second electronic front curtain.

Abstract: Image data may be color graded, distributed and viewed on target displays. Mappings that preserve mid-range points and mid-range contrast may be applied to view the image data for color grading and to prepare the image data for display on a target display. The image data may be expanded to exploit the dynamic range of the target display without affecting mid-tone values.

Abstract: White balance correction is performed on RGB color signals output from an image pickup device that includes a particular color filter array in which RGB color filters are arranged on respective lines and the ratios of the numbers of RGB color filters are different between the lines. For calculation of WB gains used for the white balance correction, not all the pixels of the image pickup device but prescribed lines are used to thinning-read. The WB gains are calculated based on color signals on the thinning-read prescribed lines. As the prescribed lines to be thinning-read, lines having a small degree of color mixture are selected under an imaging condition (a lens f-number and a zoom position) with a high degree of color mixture; lines having relatively even ratios of the numbers of RGB color filters are selected under an imaging condition having a low degree of color mixture.

Abstract: Image capturing is performed with an image pickup element being exposed to light, whereby a plurality of pieces of exposure image data are obtained. Image processing is performed on the plurality of pieces of exposure image data. The plurality of pieces of exposure image data output are combined into combined exposure image data. A plurality of pieces of dark image data are obtained and one piece of dark reference image data is generated. Image processing that uses a parameter based on the image processing performed on each exposure image data is performed on the one piece of dark reference image data, whereby a plurality of pieces of processed dark image data are output. The plurality of pieces of processed dark image data are combined into combined dark image data. The combined exposure image data is corrected in accordance with the combined dark image data.

Abstract: A portable electronic device with camera function and an image capture method with auto exposure control. The disclosed method comprises the following steps: obtaining a pre-view frame from a camera module; dividing the pre-view frame into a plurality of blocks and calculating representative brightness values of the blocks; assigning weight values to the blocks according to the representative brightness values; obtaining a weighted brightness value by performing a weighted operation on the representative brightness values based on the weight values of the blocks; setting an auto exposure parameter of the camera module based on the weighted brightness value; and controlling the camera module for capturing images based on the auto exposure parameter.

Abstract: An example method of multi-target automatic exposure and gain control based on pixel intensity distribution includes capturing a series of digital images with an image sensor. As the series of digital images are captured, exposure time and/or gain are adjusted to adjust a mean intensity value of the digital images until a target mean intensity value is reached. The method includes dynamically selecting the target mean intensity value from a plurality of target mean intensity values based on a relative number of pixels, in each captured digital image, that have an intensity value that falls outside a range of intensity values.

Abstract: An image processing apparatus is provided which minimizes reduction in S/N ratio and deterioration in resolution feeling at the lens periphery when the peripheral light amount drop correction of the lens is performed. An image processing LSI to perform the peripheral light amount drop correction of the imaging lens includes a space-direction noise removal correction part and a time-direction noise removal correction part. As the distance from the lens center position increases, the space-direction noise removal correction part reduces the noise reduction correction intensity to the image region to which the light amount drop correction gain is added in each image. As the distance from the lens center increases, the time-direction noise removal correction part increases the noise removal correction intensity to the image region to which the light amount drop correction gain is added in each image.

Abstract: An image pickup apparatus and method which reduces fixed pattern noise appearing in multiple exposure shooting and which can obtain a high-quality multiple exposure image. Multiple pieces of exposure image data are obtained by exposing an image pickup device. The multiple pieces of exposure image data are subjected to image processing. The multiple pieces of image processed exposure image data are synthesized to generate synthesized exposure image data. Multiple pieces of dark image data are obtained by shielding the image pickup device from light. Each of the multiple pieces of dark image data is subjected to image processing equivalent to image processing performed on a corresponding one of the multiple pieces of exposure image data. The multiple pieces of image processed dark image data that are synthesized to generate synthesized dark image data. The synthesized exposure image data is corrected on the basis of the synthesized dark image data.

Abstract: An imaging apparatus includes an imaging element, a reading scheme setting unit, and an image processing unit. A phase-difference detecting pixel for detecting a focal point is arranged at part of the imaging pixels of the imaging element. The reading scheme setting unit sets a reading scheme for reading pixel data from the imaging pixels and phase-difference detecting pixel. The image processing unit corrects the pixel data of the phase-difference detecting pixel. The image processing unit performs the correction, to change a use ratio of the pixel data of the phase-difference detecting pixel to the data interpolated from the pixels adjacent to the phase-difference detecting pixel.

Abstract: An image pickup device is provided, capable of complete correction with data of once analog-to-digital conversion, and prevention of excess use of switches and analog devices and/or erroneous correction, including: an image sensor having a plurality of analog-to-digital converters determining conversion results from a digital signal of higher order bit through separate steps of two or more times; a first correction unit which has a correction factor for correcting nonlinear errors of the plurality of analog-to-digital converters so as to adapt to the analog-to-digital converters and corrects a nonlinear error of a digital signal output from respective analog-to-digital converters based on a correction factor corresponding to respective analog-to-digital converters, characterized in that the first correction unit corrects the nonlinear errors after converting the digital signals from the plurality of analog-to-digital converters into a serial output.

Abstract: In one embodiment of the invention, there is provided a method of correcting a captured image for lens shading artifacts, comprising for a given lens determining a function L(x,y) being a lens shading correction function to be applied to images captured by the lens in order to correct for lens shading artifacts; applying a sampling technique to sample the function L(x,y) at selected points; and storing the sampled function L(x,y) in memory.

Abstract: Provided are a method and apparatus for controlling adaptive exposure, and an image sensor including the same. The method includes calculating a pixel saturation level of an entirety of pixels provided within an image frame and resetting a target brightness value according to the pixel saturation level; and controlling an exposure level of the pixels such that pixel brightness values of the pixels are within the target brightness value and a predetermined range.

Abstract: There are provided an image capture apparatus which can implement good tone gradation at various shooting sensitivities without preparing a nonlinear conversion characteristic for each shooting sensitivity, and a method of controlling the apparatus. If the shooting sensitivity is less than the standard sensitivity, nonlinear conversion processing is performed by linearly converting the range of signal levels obtained by shooting operation with an image sensor sensitivity corresponding to the standard sensitivity such that the maximum value decreases with a decrease in shooting sensitivity.

Abstract: A first plurality of images of a scene may be captured. Each image of the first plurality of images may be captured with a different total exposure time (TET). Based at least on the first plurality of images, a TET sequence may be determined for capturing images of the scene. A second plurality of images of the scene may be captured. Images in the second plurality of images may be captured using the TET sequence. Based at least on the second plurality of images, an output image of the scene may be constructed.

Abstract: An image processing apparatus includes an imaging unit that is configured to acquire a plurality of images with different exposure times, a position offset detection unit that is configured to detect a position offset between a plurality of images filmed by the imaging unit, a combining ratio calculation unit that is configured to calculate a combining ratio in case of combining the plurality of images based on pixel values of at least one image among the plurality of images filmed by the imaging unit and the amount of the position offset detected by the position offset detection unit, and an image combining unit that is configured to combine the plurality of images based on the combining ratio calculated by the combining ratio calculation unit.

Abstract: An amplification circuit includes an amplifier, a first capacitor including a first terminal connected to an input terminal of the amplifier, a second capacitor including a first terminal connected to the input terminal of the amplifier and a second terminal connected to an output terminal of the amplifier, and a correction unit configured to correct a difference in bias dependency between capacitance values of the first and second capacitors.

Abstract: An image processing apparatus includes a calculation unit configured to calculate a first gain for adjusting brightness of a first image and a second image based on the first image captured at a first exposure amount and the second image captured at a second exposure amount, a division unit configured to divide the first gain into a second gain which changes according to a position in an image and a third gain which does not change according to a position in an image, a first gain correction unit configured to perform gain correction on the second image with the second gain, and a second gain correction unit configured to perform gain correction on the second image with the third gain.

Abstract: This invention discloses an image pickup device and an image synthesis method thereof The image pickup device comprises an image-pickup module, an image-synthesis module, a database and a processing module. The image-pickup module captures a plurality of temporary images of a scene. The image-synthesis module extracts a part of each temporary image and combines the parts to form a panorama temporary image, and splits the panorama temporary image into a plurality of zone-areas according to at least one threshold value and a panorama luminosity histogram. The database stores a lookup table for recording a plurality of exposure values. The plurality of the exposure values correspond to luminance values of the zone-areas respectively. The processing module obtains the plurality of exposure values corresponding to the luminance values and obtains a weighting-exposure value by an equation, and controls the image-pickup module to capture the panorama image according to the weighting-exposure value.

Abstract: A method, apparatus, and system for dynamic range estimation of imaged scenes for automatic exposure control. For a given exposure time setting, certain areas of a scene may be brighter than what a camera can capture. In cameras, including those experiencing substantial lens vignetting, a gain stage may be used to extend dynamic range and extract auto-exposure data from the extended dynamic range. Alternatively, dynamic range can be extended using pre-capture image information taken under reduced exposure conditions.

Abstract: Image data is processed to facilitate focusing and/or optical correction. According to an example embodiment of the present invention, an imaging arrangement collects light data corresponding to light passing through a particular focal plane. The light data is collected using an approach that facilitates the determination of the direction from which various portions of the light incident upon a portion of the focal plane emanate from. Using this directional information in connection with value of the light as detected by photosensors, an image represented by the light is selectively focused and/or corrected.

Abstract: When imaging bright objects, a conventional detector array can saturate, making it difficult to produce an image with a dynamic range that equals the scene's dynamic range. Conversely, a digital focal plane array (DFPA) with one or more m-bit counters can produce an image whose dynamic range is greater than the native dynamic range. In one example, the DFPA acquires a first image over a relatively brief integration period at a relatively low gain setting. The DFPA then acquires a second image over longer integration period and/or a higher gain setting. During this second integration period, counters may roll over, possibly several times, to capture a residue modulus m of the number of counts (as opposed to the actual number of counts). A processor in or coupled to the DFPA generates a high-dynamic range image based on the first image and the residues modulus m.

Abstract: A photographing apparatus and method for dynamic range adjustment and stereography are provided. The photographing apparatus includes a first imaging device for converting a light of a subject received through a first optical system into an electric signal; a second imaging device for converting a light of the subject received through a second optical system into an electric signal; a first image signal processor for generating an image signal for live view based on the electric signal output from the first imaging device before a photographing operation of a still image; an exposure controller for controlling an exposure so as to perform a step exposure in the second imaging device before the photographing of the still image; and an exposure calculator for calculating an exposure amount in the photographing operation of the still image based on the electric signal converted in the second imaging device obtained through the step exposure.

Abstract: An image pickup apparatus that is capable of reducing the load of the process required to combine images with different exposures to generate a composite image. An image pickup unit performs continuous image pickup that shoots a subject continuously under different exposure conditions. A control unit controls the image pickup unit so that the exposure condition for the first shot in a current set, which is a second or later set, is coincident with the exposure condition for the last shot in the previous set when a plurality of sets of the continuous image pickup are performed. A composing unit composes the images acquired by one set of the continuous image pickup by the image pickup unit to generate one output image.

Abstract: Apparatus and methods are provided to create high dynamic range images by passing an incoming image through a color-neutral separation prism having at least three channels to produce a corresponding number of full color fractionated images, each channel aligned with a corresponding image capturing device for which an ISO sensitivity is selected to simultaneously achieve a different exposure value for each fractionated image and image capturing device, referred to as exposure bracketing, and recombining the simultaneously collected fractionated images to create a high dynamic range image. The apparatus and methods may be used for still photography or motion pictures.

Abstract: A method of capturing a digital image with a digital camera includes determining a first exposure level for capturing an image based on a first luminance level of the image, determining a second exposure level for capturing the image based on a threshold exposure level of the image, configuring an exposure level of a sensor of the digital camera based on the second exposure level, capturing the image as a digital image, and adding a non-linear digital gain to the digital image based on a difference between the first exposure level and the second exposure level.

Abstract: An image capturing device includes an image data generation unit, a display control unit and a control unit. The control unit ends charge storing after a first amount of time passes since charge storing of an image capturing target line is started, and starts displaying image data of a display target line corresponding to the image capturing target line after a second amount of time passes since charge storing of an image capturing target line is ended. The second amount of time is time required for starting displaying image data in a display target line after charge storing of an image capturing target line is ended. The control unit starts charge storing of an image capturing target line such that the first amount of time is equal to or less than a vertical synchronization period of the image capturing sensor minus the second amount of time.

Abstract: Apparatus and methods are provided for obtaining high dynamic range images using a low dynamic range image sensor. The scene is exposed to the image sensor in a spatially varying manner. A variable-transmittance mask, which is interposed between the scene and the image sensor, imposes a spatially varying attenuation on the scene light incident on the image sensor. The mask includes light transmitting cells whose transmittance is controlled by application of suitable control signals. The mask is configured to generate a spatially varying light attenuation pattern across the image sensor. The image frame sensed by the image sensor is normalized with respect to the spatially varying light attenuation pattern. The normalized image data can be interpolated to account for image sensor pixels that are either under or over exposed to enhance the dynamic range of the image sensor.

Abstract: A light intensity control device includes a fixed opening 261, an aperture stop part 26 for controlling a light flux of incident light, a light intensity aperture part 24 for changing the size of an opening by moving a plurality of aperture blades to limit a light intensity of transmitted light and a ND filter 25 having a transparent area 253 and a light blocking area 254, which is arranged to be movable between a first light blocking state where the transparent area 253 faces the fixed opening 261 of the aperture stop part 26 and a second light blocking state where the light blocking area 254 faces the fixed opening. The moving of the ND filter 25 is carried out when the opening area of the light intensity aperture part 24 is a maximum.

Abstract: An improved non-uniform sensitivity correction algorithm for use in an imager device (e.g., a CMOS APS). The algorithm provides zones having flexible boundaries which can be reconfigured depending upon the type of lens being used in a given application. Each pixel within each zone is multiplied by a correction factor dependent upon the particular zone while the pixel is being read out from the array. The amount of sensitivity adjustment required for a given pixel depends on the type of lens being used, and the same correction unit can be used with multiple lenses where the zone boundaries and the correction factors are adjusted for each lens. In addition, the algorithm makes adjustments to the zone boundaries based upon a misalignment between the centers of the lens being used and the APS array.

Abstract: A camera array, an imaging device and/or a method for capturing image that employ a plurality of imagers fabricated on a substrate is provided. Each imager includes a plurality of pixels. The plurality of imagers include a first imager having a first imaging characteristics and a second imager having a second imaging characteristics. The images generated by the plurality of imagers are processed to obtain an enhanced image compared to images captured by the imagers. Each imager may be associated with an optical element fabricated using a wafer level optics (WLO) technology.

Abstract: An example method of multi-target automatic exposure and gain control based on pixel intensity distribution includes capturing a series of digital images with an image sensor. As the series of digital images are captured, exposure time and/or gain are adjusted to adjust a mean intensity value of the digital images until a target mean intensity value is reached. The method includes dynamically selecting the target mean intensity value from a plurality of target mean intensity values based on a relative number of pixels, in each captured digital image, that have an intensity value that falls outside a range of intensity values.