Abstract: Automatic weight adjustment (AWA) to derive an optimal color correction matrix may address unbalanced color reproduction performance among different illuminations and/or unbalanced color reproduction performance for specific memory colors. AWA may emphasize particular colors and equalize color performance. AWA may be implemented in an automatic process with optional manual operation.

Abstract: Embodiments include methods of image processing in which pixels of an image are classified according to color. An exposure control operation is performed according to the pixel classifications. In one example, the pixels are classified according to a predetermined segmentation of a color space, based on predicted sensor responses. In another example, the pixels are classified according to a color selected from among at least two colors.

Abstract: The registration of images comprising segmenting an image in a frame into a set of sectors which forms a circle. Generating a plurality of sets of projections in a base frame, wherein each set of projections is generated from any sector amongst the set of sectors from the base frame. Also generating a plurality of sets of projections in a movement frame, wherein each set of projections is generated from any sector amongst the set of sectors from the movement frame. Then summing each set of projections, from any sector amongst the set of sectors from the base frame and summing each set of projections from any sector amongst the set of sectors from the movement frame. Furthermore, comparing a set of each sum of projections from the base frame with a set of each sum of projections from the movement frame, and generating a rotation angle estimate to add to the base frame.

Abstract: A camera system in normal mode and hand jitter reduction (hjr) mode may comprise generating a first exposure time-gain product by multiplying the normal mode exposure time with the normal mode gain. It may further comprise modifying the normal mode exposure time and gain and multiplying these modified parameters to generate a second exposure time-gain product for a hjr mode that reduces the difference between the first exposure time-gain product and the second exposure time-gain product. To reduce the difference the normal mode frame rate may also be modified. Operation of a camera in normal mode may be in response to a sensed light level being above a threshold. The hjr mode may be selected by the user while the camera is operating. The hjr mode may be used in response to a sensed light level being lower than the threshold.

Abstract: The disclosure is directed to techniques for automatic focus control. The automatic focus control techniques prioritize focus of a camera based on skin tone using a skin color detection approach which is intrinsically image sensor-dependent. Sensor-dependent skin color detection to support automatic skin tone prioritized focus control in a camera can enhance the focus of people in the scene. The techniques may be especially useful in digital video camera design, digital still photo camera design, and sensor applications involving people tracking. Sensor-dependent skin color detection is performed once a specific sensor is characterized by taking several raw images of a standard color test target in controlled illumination conditions. Sensor-dependent skin color detection can provide high detection precision and reliability. With sensor-dependent skin color detection, the focus of a camera can be automatically adjusted to prioritize regions of an image containing skin tones.

Abstract: The disclosure is directed to techniques for region-of-interest (ROI) video processing based on low-complexity automatic ROI detection within video frames of video sequences. The low-complexity automatic ROI detection may be based on characteristics of video sensors within video communication devices. In other cases, the low-complexity automatic ROI detection may be based on motion information for a video frame and a different video frame of the video sequence. The disclosed techniques include a video processing technique capable of tuning and enhancing video sensor calibration, camera processing, ROI detection, and ROI video processing within a video communication device based on characteristics of a specific video sensor. The disclosed techniques also include a sensor-based ROI detection technique that uses video sensor statistics and camera processing side-information to improve ROI detection accuracy.

Abstract: The disclosure is directed to techniques for region-of-interest (ROI) video processing based on low-complexity automatic ROI detection within video frames of video sequences. The low-complexity automatic ROI detection may be based on characteristics of video sensors within video communication devices. In other cases, the low-complexity automatic ROI detection may be based on motion information for a video frame and a different video frame of the video sequence. The disclosed techniques include a video processing technique capable of tuning and enhancing video sensor calibration, camera processing, ROI detection, and ROI video processing within a video communication device based on characteristics of a specific video sensor. The disclosed techniques also include a sensor-based ROI detection technique that uses video sensor statistics and camera processing side-information to improve ROI detection accuracy.

Abstract: Embodiments include a method of image processing including decomposing a reflectance spectrum for a test surface into a linear combination of reflectance spectra of a set of test targets. The coefficient vector calculated in this decomposition is used to predict a response of an imaging sensor to the test surface. A plurality of such predicted responses may be used for various applications involving color detection and/or classification, including human skin tone detection.

Abstract: Luma adaptation for digital image processing. Luminance signals are separated from sensor RGB signals representing an image. A transfer function is obtained from the luminance signals. Using the transfer function, the sensor RGB signals are adjusted to adapt the luma of the image.

Abstract: An apparatus, system, and method provide optimization of color space conversion using a joint quality metric representing differences between reference human visual representations and converted device captured image representations in a perceptual uniform color space, where the conversion includes transforming a nonstandard color space (RGB) to a perceptual standard color space (sRGB) and where the joint quality metric includes a color portion, a noise portion, and a contrast portion. An optical sensor produces a digital reference signal when capturing an image of a reference source such as a Macbeth ColorChecker color rendition chart. After white balancing and color correcting the digital reference signal, the gamma curve parameters are determined by minimizing the joint quality metric which is based on differences, within a uniform perceptual color space such as CIELAB, between the gamma curve compensated signal and the standard values for the reference source.

Abstract: To improve the color performance, disclosed herein are advanced methods for improving chroma accuracy, by reducing the color difference between reproduced colors and human perceptual responses, as well as enhancing preferred colors. Chroma enhancement may be performed by selecting one of a plurality of chroma enhancement matrices (CEM), and converting a received color by multiplying it with the chroma enhancement matrix (or a matrix comprising the CEM). The matrix may be selected by mapping a received color value into a region and selecting the corresponding chroma enhancement matrix (or alternately, the corresponding parameters, from which color conversion may be performed). Additionally, enhancement may be adjusted for a variety of environments or preferences. For example, one of a plurality of sets of matrices may be selected in accordance with a desired mode. Optimization techniques for determining the desired chroma enhancement matrices for one or more modes are disclosed.