摘要:
A method and apparatus for applying exposure compensation to an image. Exposure correction limits inclusion of, but does not ignore, image highlights and lowlights.
摘要:
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.
摘要:
A method and apparatus for applying color correction to image signals provides different color corrections depending on a characterization associated with a pixel signal being processed or the gain applied to the pixel signal such as a value of a pixel signal being processed. The color corrections may be configured such that darker pixels have less color correction applied to them.
摘要:
A method, apparatus, and system are provided by which image line data of an image frame is compressed before being stored to image line memory used in multiple image line processing.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.