Abstract: A digital image system identifies defective pixels of a digital image sensor based on sensor values of pixels positioned in at least two dimensions on the digital image sensor. The exemplary imaging system includes a buffer for receiving sensor values that are each associated with a pixel in the digital image sensor and electronics for comparing the sensor value associated with a test pixel to the sensor values of pixels positioned in at least two dimensions on the digital image sensor. The electronics determines whether the test pixel is a defective pixel based on the comparison.

Abstract: Techniques for identifying and enhancing colors in a digital image associated with one or more target color shades. In an embodiment, the target color shades may include a shade of blue associated with the sky, a shade of green associated with outdoor foliage, or the color red. In an embodiment, the blue chroma (Cb) and red chroma (Cr) coordinates of a pixel are evaluated to determine whether to apply an enhancement factor. The enhancement factor may incorporate an exposure index (EI) auxiliary enhancement factor, a color temperature (D) auxiliary enhancement factor, and a luminance (Y) of each pixel. Further aspects for implementing the techniques in software and hardware are disclosed.

Abstract: This disclosure describes automatic self-calibration techniques for digital camera devices. In one aspect, a method for performing a calibration procedure in a digital camera device comprises initiating the calibration procedure when a camera sensor of the digital camera device is operating, accumulating data for the calibration procedure, the data comprising one or more averages of correlated color temperature (CCT) associated with information captured by the camera sensor, calculating one or more CCT vectors based on the one or more averages of CCT, and generating gray point correction factors based on the one or more CCT vectors.

Abstract: The disclosure relates to techniques for calibration of an auto-focus process in an image capture device. The techniques may involve calibration of a lens actuator used to move a lens within a search range during an auto-focus process. For example, an image capture device may adjust reference positions for the search range based on lens positions selected for different focus conditions. The different focus conditions may include a far focus condition and a near focus condition. The focus conditions may be determined based on a detected environment in which the device is used. Detection of an indoor environment may indicate a likelihood of near object focus, while detection of an outdoor environment may indicate a likelihood of far object focus. An image capture device may detect indoor and outdoor environments based on lighting, exposure, or other conditions.

Abstract: In general this disclosure describes techniques for configuring an image sensor of an image capture device based on motion within the scene of interest. In particular, the image capture device analyzes motion between two or more images of the same scene of interest and adjusts the configuration parameters, e.g., gain and/or exposure time, of the image sensor based on the amount of motion within the scene of interest. For example, the image capture device may configure the image sensor with a large gain and a short exposure time when the scene includes a relatively large amount of motion, thus reducing the blur caused by the large amount of motion. Conversely, the image capture device may configure the image sensor with a small gain and a long exposure time when the scene includes relatively little or no motion, thus reducing the noise caused by large gains.

Abstract: A two-dimensional (2D) mesh is applied over a distortion surface to approximate a lens roll-off distortion pattern. The process to apply the 2D mesh distributes a plurality of grid points among the distortion pattern and sub-samples the distortion pattern to derive corrected digital gains at each grid location. Non-grid pixels underlying grid blocks having a grid point at each corner are adjusted based on the approximation of the lens roll-off for the grid points of the grid block. In one example, bilinear interpolation is used. The techniques universally correct lens roll-off distortion irregardless of the distortion pattern shape or type. The technique may also correct for green channel imbalance.

Abstract: A device has a processing unit to implement a set of operations to use both luma and chroma information from a scene of an image to dynamically adjust exposure time and sensor gain. The processing unit collects bright near grey pixels and high chroma pixels in the scene. Based on the collected pixels, brightness of the near grey pixels is increased to a predetermined level without saturation. At the same time, the high chroma pixels are kept away from saturation.

Abstract: Automatic white balance of captured images can be performed based on a gray world assumption. One aspect relates to an apparatus comprising a collection module and a processor. The collection module is configured to accumulate (a) red/green and blue/green color ratio values of a plurality of pixels in a captured image for each cluster of a plurality of clusters and (b) a number of pixels having red/green and blue/green color ratios associated with each cluster, the clusters comprising daylight, fluorescent, incandescent, and a outdoor green zone. The processor is configured to determine which cluster has a highest accumulated number of pixels, and use the cluster with the highest accumulated number of pixels to perform white balancing for the captured image.

Abstract: Apparatus are provided including an image signal carrier, a luminance information evaluator, and a chrominance information modifier. The image signal carrier is encoded with an image signal including luminance information and chrominance information. The luminance information evaluator evaluates the luminance information in the image signal for a given region within the image to identify when the given region is one of substantially white and substantially dark.

Abstract: Techniques are described for predictive focus value calculation within image capture devices. Image capture devices may include digital still cameras and digital video cameras. The techniques include performing an auto-focus process within an image capture device by predicting a focus value for a scene at a lens position of a lens included in the image capture device based on a corrupt focus value for the lens position calculated from a first frame directly after lens settlement. Therefore, the auto-focus process may determine size and direction of movement for the lens to a next lens position based on the predicted valid focus value, and move the lens to the next lens position during a second frame. In this way, the techniques may move the lens to another lens position during each frame, greatly reducing auto-focus latency by potentially doubling or tripling the speed of the auto-focus process.

Abstract: An adaptive filter according to one embodiment includes an N×N two-dimensional convolution, where N is an odd integer greater than one. Pixels of an image are filtered by moving the N×N kernel across the image. At each pixel location, the kernel coefficients are determined by the image pixels within the N×N region, such that the kernel coefficients may change from one pixel location to the next. Such a filter may be implemented to use a lookup table to approximate a floating-point operation.

Abstract: This disclosure describes image processing techniques that facilitate the determination of the lighting condition associated with an image. Once the lighting condition is determined, white balance can be performed on the image such as by applying white balance gains defined for the lighting condition. According to the techniques of this disclosure, gray point lines are defined and plotted for the different lighting conditions, and cylindrical bounding volumes are defined around the gray point lines, e.g., in a three-dimensional color space. The image is then analyzed with respect to each of the cylindrical bounding volumes to determine how many pixels of the image fall within the respective cylindrical bounding volumes formed around the gray point lines for the different lighting conditions. Based on this analysis, the actual lighting condition can be determined.

Abstract: A system and method are provided for robust Motion Picture Experts Group (MPEG-2) multiplexing information using an adjustable time stamp. The method comprises: accepting a plurality of digital programs; encoding each program into frames; generating a decoding time stamp (DTS) and a corresponding presentation time stamp (PTS), measured with respect to a program clock reference (PCR) for each frame; generating a packetized elementary stream (PES) packet, with a PES header including the PCR, DTS, and PTS, for each frame; time division multiplexing (TDM) the PES packets into a MPEG-2 transport stream; at the time of insertion into the MPEG-2 transport stream, comparing the DTS and PTS values to the PCR value in each header; modifying the DTS value in the PES header in response to the comparison; and, transmitting the MPEG-2 transport stream.

Abstract: A digital image system identifies defective pixels of a digital image sensor based on sensor values of pixels positioned in at least two dimensions on the digital image sensor. The exemplary imaging system includes a buffer for receiving sensor values that are each associated with a pixel in the digital image sensor and electronics for comparing the sensor value associated with a test pixel to the sensor values of pixels positioned in at least two dimensions on the digital image sensor. The electronics determines whether the test pixel is a defective pixel based on the comparison.

Abstract: A method and apparatus for adaptive green channel odd-even mismatch removal to effectuate the disappearance of artifacts caused by the odd-even mismatch in a demosaic processed image. In one adaptive approach, a calibrated GR channel gain for red rows and a calibrated GB channel gain for blue rows are determined and are a function of valid pixels only in each respective region. After the calibration, in a correction process, the green pixels in red rows of a region are multiplied by the calibrated GR channel gain. On the other hand, the green pixels in blue rows are multiplied by the calibrated GB channel gain. Thus, after demosaic processing, the corrected image has essentially no artifacts caused by odd-even mismatch of the green channel. Alternately, the adaptive green channel odd-even mismatch removal method replaces the center green pixel of a region having an odd number of columns and rows with a normalized weighted green pixel sum total.

Abstract: A system and method are provided for broadcasting information compressed using the MPEG-4 standard. The method comprises: packetizing MPEG-4 compressed visual object sequence (VOS) data into an elementary stream (ES); for each VOS header in the ES, generating a first plurality of visual object (VO) and video object layer (VOL) headers; associating a second plurality of video object planes (VOPs) with each VO-VOL header; and, transmitting the ES. An Intra type VOPs (I-VOPs) is associated with a random access unit (RAU) and each VO-VOL header is associated with an I-VOP header. An alternate method comprises: accepting an initial program including IODs, ODs, and BIFSs; packetizing MPEG-4 compressed VOS data into an MPEP-2 ES; portioning the ES into RAUs including initial object descriptors (IODs), object descriptors (ODs), and scene description streams (binary format for scenes; BIFS); and, transmitting the ES.

Abstract: A system and method are provided for robust Motion Picture Experts Group (MPEG-2) multiplexing information using an adjustable time stamp. The method comprises: accepting a plurality of digital programs; encoding each program into frames; generating a decoding time stamp (DTS) and a corresponding presentation time stamp (PTS), measured with respect to a program clock reference (PCR) for each frame; generating a packetized elementary stream (PES) packet, with a PES header including the PCR, DTS, and PTS, for each frame; time division multiplexing (TDM) the PES packets into a MPEG-2 transport stream; at the time of insertion into the MPEG-2 transport stream, comparing the DTS and PTS values to the PCR value in each header; modifying the DTS value in the PES header in response to the comparison; and, transmitting the MPEG-2 transport stream.