Abstract: Methods and apparatuses for image exposure include capturing a first image under a first illumination condition, determining a luminance of the first image at a plurality of sectors, capturing a second image under a second illumination condition employing an artificial light source, determining a luminance of the second image at the plurality of sectors, and determining if the artificial light source should be used to capture a final image using the luminances of the first and second images at the plurality of sectors. If the artificial light source is to be used, an output level of the light source is determined.

Abstract: An apparatus and method for measuring the breakpoint of a response curve representing the voltage output of an image array having an extended dynamic range. By flooding a light-opaque pixel with a charge and then applying an intermediate reset voltage to the pixel, the signal is read from the pixel and stored. The full reset voltage is applied to the pixel, and then the signal in the pixel is read and stored. The voltage output difference is the difference between the first and second stored signal. The voltage output difference is then used to determine the voltage of the knee point. Further, a conventional saturated pixel can be reset with an intermediate reset just prior to readout. The resulting signal can then be used to determine the voltage of the knee point.

Abstract: Methods, systems and apparatuses for determining and compensating for green imbalance in imagers. An estimated local green balance correction term is limited, e.g., between an upper and lower limit. The upper and lower limits are determined from a set of parameters. The parameters are determined during a calibration procedure.

Abstract: Method, apparatus and system for determining a value for green-green imbalance and applying the value to green pixels to correct the imbalance are described. Average pixel values of green pixels within a kernel are calculated and an imbalance value is determined based on the averages. The imbalance value is added to or subtracted from all green pixel response values in the kernel to correct the imbalance.

Abstract: A method and apparatus for processing an image. Specifically, one exemplary embodiment of the method comprises inputting an image into a pixel array producing pixel output signals, executing an image edge detection routine on the pixel output signals that detects pixels defining an image edge, grouping the edge defining pixels into a predetermine plurality of regions based on luminance intensity values of the edge defining pixels, using the grouping to define a non-linear transform function operation over a range of luminance intensity values of the edge defining pixels, applying the non-linear transform function to luminance intensity values, and using the edge defining pixels having the applied non-linear transform function to produce an enhanced image from the input image. One exemplary embodiment of the apparatus comprises a programmed processor that executes the method described above.

Abstract: Surface generation and positional gain adjustment techniques for an imager are described. Embodiments of the techniques use 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 correction factors comprise coefficients that are different for each color channel and in some instances different for each corner of each color channel.

Abstract: An image window is subdivided into a plurality of sub-windows arranged in a rectangular grid pattern. The average brightness of the window and each sub-window is determined. A sub-window is tagged as dark if its average brightness is a predetermined percentage of the window average brightness. If the sub-window in the center of the grid pattern is considered to be dark, a segmentation is performed to detect a main backlit subject. The comparison of sub-window brightness is continued from the center sub-window in outward sequential, side adjacent rows and columns of sub-windows. Each sub-window that meets the above-described criterion for being dark is tagged as dark. The image is considered to have a main backlit subject if, in one embodiment, the subject is comprised of a predetermined quantity of continuous, dark sub-windows.

Abstract: The various embodiments described herein provide for the correction of spectral imbalance as might be caused where first pixels corresponding to a first spectral response have two or more different patterns of neighboring pixels contributing to cross-talk interference with the response of those first pixels. The differing patterns of neighboring pixels generally produce differing levels of contribution to the response of the first pixels even when subjected to the same illumination. By determining an average response of a first set of the first pixels having a first pattern of neighboring pixels and an average response of a second set of the first pixels having a second pattern of neighboring pixels, corrections for one or both of the sets of the first pixels can be determined to facilitate a mitigation of the spectral imbalance.

Abstract: Embodiments described herein may operate to compare an illuminance corresponding to a signal from an image sensor array (ISA) element in a production imaging system with an illuminance associated with optical flare incident to an ISA from which the ISA element is selected. The ISA element may be identified as unusable if the illuminance corresponding to the signal from the ISA element is less than the illuminance associated with the optical flare incident to the ISA.

Abstract: A method and apparatus for processing imager pixel signals to reduce noise. The processing includes receiving a target pixel signal, receiving at least one neighboring pixel signal, formulating a dynamic noise signal based at least in part on a value of the target pixel signal, and controlling a noise reduction operation using the dynamic noise signal.

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: Embodiments described herein may operate to image a scene with an imaging system using an image blurring technique. An image sensor array (ISA) element may be identified as a dark defect element if a first ratio of an average of a set of illuminance signal magnitudes from a set of surrounding ISA elements to a magnitude of an illuminance signal from the ISA element is greater than a threshold sharpness value. The image sensor array element may be identified as a bright defect element if a second ratio of the magnitude of the illuminance signal from the ISA element to the average of the set of illuminance signal magnitudes from the set of surrounding ISA elements is greater than the threshold sharpness value.

Abstract: A solid state imaging device includes an array of active pixels and an infrared cut filter formed over the sensor. Optionally, a slot in the infrared cut filter allows infrared illumination to reach the sensor to be detected by pixels covered by a visually opaque filter and surrounded by pixels of special types that limit charge leakage and enable high dynamic range sensing of infrared illumination. A ratio of average infrared signal to average brightness indicates an amount of infrared illumination reaching the imaging device.

Abstract: Surface generation and positional gain adjustment techniques for an imager are described. Embodiments of the techniques use 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 correction factors comprise coefficients that are different for each color channel and in some instances different for each corner of each color channel.

Abstract: A method and apparatus for applying tonal correction to images to obtain a more pleasing photographic image by redistributing low-key, mid-tone and high-key tones. Luminance is calculated by using formulas appropriate for the color space or directly inputted. Two color-difference components are computed for the original image. Luminance is subjected to a tonal correction function to obtain a tonal corrected luminance. Luminance gain is calculated and applied to the color-difference components to obtain two tonal corrected color-difference components. The tonal corrected luminance and two tonal corrected color-difference components can be directly output or used to calculate three color component signals for the desired color space.

Abstract: An apparatus and method for measuring the breakpoint of a response curve representing the voltage output of an image array having an extended dynamic range. By flooding a light-opaque pixel with a charge and then applying an intermediate reset voltage to the pixel, the signal is read from the pixel and stored. The full reset voltage is applied to the pixel, and then the signal in the pixel is read and stored. The voltage output difference is the difference between the first and second stored signal. The voltage output difference is then used to determine the voltage of the knee point. Further, a conventional saturated pixel can be reset with an intermediate reset just prior to readout. The resulting signal can then be used to determine the voltage of the knee point.

Abstract: A method and apparatus are provided for determining which pixels of a plurality of pixels have outputs which are reflecting of the color temperature of a light source. Those pixels which are determined to be representative of a light source may be used in a white balance operation. In the method and apparatus of the invention, the pixels are examined for a relationship among the color components (e.g., R, G, B) of a pixel which meet a predetermined criteria. Those pixels which meet the criteria are used in a white balance operation.

Abstract: A system and method for flare cancellation and image contrast restoration. The method includes generating a histogram of pixel response values of pixels of an image and generating an adjustment signal having a luminance adjustment value responsive to said histogram; and adjusting the pixel response values of pixels of said image responsive to the adjustment signal to produce an adjusted image.

Abstract: A method and apparatus for processing an image. Specifically, one exemplary embodiment of the method comprises inputting an image into a pixel array producing pixel output signals, executing an image edge detection routine on the pixel output signals that detects pixels defining an image edge, grouping the edge defining pixels into a predetermine plurality of regions based on luminance intensity values of the edge defining pixels, using the grouping to define a non-linear transform function operation over a range of luminance intensity values of the edge defining pixels, applying the non-linear transform function to luminance intensity values, and using the edge defining pixels having the applied non-linear transform function to produce an enhanced image from the input image. One exemplary embodiment of the apparatus comprises a programmed processor that executes the method described above.

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.