Abstract: An apparatus for controlling the position of a screen pointer includes an at least partially coherent light source for illuminating an imaging surface, thereby generating reflected images. The apparatus includes a navigation sensor for generating digital images based on the reflected images, performing a movement computation based on the digital images, generating movement data based on the movement computation that is indicative of relative motion between the imaging surface and the apparatus, wherein the movement computation has a low sensitivity to effects in the digital images caused by particle contamination.

Abstract: Embodiments of an apparatus are described. In one embodiment, the apparatus is an optical navigation circuit. In particular, the optical navigation circuit may be part of an optical navigation device. The optical navigation circuit includes an image sensor, dynamic reconfiguration logic, and a digital signal processor. The image sensor includes a pixel array to generate a plurality of electrical signals corresponding to incident light at the pixel array. The dynamic reconfiguration logic is coupled to the image sensor. The dynamic reconfiguration logic is configured to receive the plurality of electrical signals from the pixel array and to generate a plurality of reconfigured electrical signals based on the plurality of electrical signals from the pixel array. The digital signal processor is coupled to the dynamic reconfiguration logic. The digital signal processor is configured to receive the plurality of reconfigured electrical signals from the dynamic reconfiguration logic.

Abstract: An apparatus for controlling the position of a screen pointer includes an at least partially coherent light source for illuminating an imaging surface, thereby generating reflected images. The apparatus includes a navigation sensor for generating digital images based on the reflected images, performing a movement computation based on the digital images, generating movement data based on the movement computation that is indicative of relative motion between the imaging surface and the apparatus, wherein the movement computation has a low sensitivity to effects in the digital images caused by particle contamination.

Abstract: An optical pointing device includes a light source configured to respond to a drive current to provide at least partially coherent light to illuminate an imaging surface to thereby generate reflected images. A navigation sensor is configured to generate digital images based on the reflected images, and generate movement data based on the digital images that are indicative of relative motion between the imaging surface and the optical pointing device. A light source driver is configured to provide the drive current to the light source. A drive current controller is configured to calibrate the drive current based on selected digital images.

Abstract: Methods for reducing artifacts caused by illuminant flicker are provided. One such method comprises: providing pixel circuits; and operating the pixel circuits in a bi-directional mode during which first information corresponding to a scene is acquired in forward row-sequential order of the pixel circuits and then second information corresponding to the scene is acquired in a reverse row-sequential order of the pixel circuits. Systems also are provided.

Abstract: A technique for adapting an optical navigation device for navigation on a transparent structure such as a glass plate involves establishing a navigation window for navigation tracking, detecting reflected light within the navigation window, generating an output signal in response to the detected light, and adjusting a characteristic of the navigation window in response to the output signal. An optical navigation device includes an illumination system configured to output light, an image sensor configured to generate an output signal related to a detected portion of the light, and a transparent structure adapter module configured to adjust a navigation window of the image sensor in response to the output signal to adapt the optical navigation device for use directly on an opaque surface or for use on a transparent structure that is located between the optical navigation device and the opaque surface.

Abstract: Reconstructing the shape of the surface of an object in greater than two dimensions is performed using a noise-tolerant reconstruction process and/or a multi-resolution reconstruction process. The noise-tolerant reconstruction process can be a Bayesian reconstruction process that adds noise information representing the noise distribution in optical image(s) of the object to surface gradient information estimated from the images to determine surface height information that defines the shape of the surface of the object in greater than two dimensions. In the multi-resolution reconstruction process, for each resolution of the image, the surface gradient information is estimated and the surface height information is calculated using the estimated surface gradient information. To obtain the final surface height map, the surface height information from each resolution is combined to reconstruct the shape of the surface of the object in greater than two dimensions.

Abstract: Apparatus and method of optically detecting click events are described. Images of a contact surface are captured at respective capture times. The captured images are convolved with a two-dimensional circularly symmetric spatial bandpass filter to produce corresponding filtered images each including a set of pixels with respective pixel value magnitudes. Based on the pixel value magnitudes of the corresponding filtered images, each of the capture times is assigned to one of an in-contact time class during which the contact surface is determined to be in-contact with a user's finger and an out-of-contact time class during which the contact surface is determined to be out-of-contact with the user's finger. A select signal indicating that the contact surface has been touched to make a selection is generated based on a click event predicate defining at least one condition on the time classes respectively assigned to successive ones of the capture times.

Abstract: A spatial filter includes a number of photodetectors that generate individual signals in the time domain. The individual signals are subsequently divided and grouped to create the I and Q channels output from the spatial filter. Prior to the formation of the I and Q channels, a window function is used to shape the spatial response of the spatial filter.

Abstract: A bad pixel correction (BPC) algorithm that can be implemented on the image sensor chip is provided for detecting and correcting defective pixels in a digital color image sensor. Gradients of neighboring pixels in at least one other color plane than the color plane of a current pixel and a range of sensor values from neighboring pixels in the same color plane as the current pixel are determined. If the sensor value of the current pixel is outside of the range by a threshold amount that is calculated using one or more of the gradients, the current pixel is determined to be a defective pixel, and replaced using the sensor values of the neighboring pixels in the same color plane.

Abstract: A repetitive surface detector includes an image capture device capturing an image. An autocorrelator receives the image and generates a signal indicative of a repetitive background of the image. A controller determines a maximum and minimum value in the auto-correlated signal. An adder determines the signed difference between the maximum and minimum value. A comparator compares the signed difference with a threshold and generates an output that indicates when the image includes a repetitive background.

Abstract: Electronic devices having image-based data input systems are described. In one aspect, an electronic device includes a window, multiple indicia, an image sensor, and a data input processor. The window has a contact surface with an input region. The multiple indicia are viewable in the input region of the contact surface. The image sensor is constructed and arranged to produce image signals corresponding to images of the input region. The data input processor is coupled to the image sensor and is operable to produce input signals based on image signals produced by the image sensor and a mapping between areas of the input region images and locations of the input indicia.

Abstract: An optical navigation system, e.g. optical mouse, determines optical navigation quality by examining some or all of the photosensors of a frame or monitoring intermediate or final results of the motion estimation system. The optical navigation quality is then used to determine the navigation output produced by the optical navigation system.

Abstract: A system and method for processing mosaiced images utilizes a compression-aware demosaicing process that takes into consideration a subsequent compression process. The compression-aware demosaicing process is performed using a compression-considered demosaicing operator that incorporates a color space conversion operator and a frequency-based transformation operator, which are typically associated with the compression process. Consequently, the overall efficiency of the system and method is significantly increased. Furthermore, the compression-aware demosaicing process produces artifacts that complement the artifacts produced by the subsequent compression process such that the artifacts are less visible in the final color images, which increases the quality of the final color images.

Abstract: An optical pointing device includes a light source configured to respond to a drive current to provide at least partially coherent light to illuminate an imaging surface to thereby generate reflected images. A navigation sensor is configured to generate digital images based on the reflected images, and generate movement data based on the digital images that is indicative of relative motion between the imaging surface and the optical pointing device. A light source driver is configured to provide the drive current to the light source. A drive current controller is configured to calibrate the drive current based on selected digital images.

Abstract: Previously-unused slots in a Huffman code table associated with a Joint Photographic Experts Group (JPEG) image file are associated with various quantization matrices (Q matrices) that are used to quantize data blocks of the JPEG image file. Huffman codes associated with the various Q matrices permit the particular Q matrix used to quantize a given data block to be signaled by a decoder as an end-of-block (EOB) code. The EOB codes and the Huffman code table are sent with the JPEG image file. Upon decoding of the image file, a standard JPEG decoder reads each of the EOB codes as a standard JPEG EOB code and does not vary the Q matrix. A modified decoder reads from each of the EOB codes which Q matrix was used to encode each particular data block of the image and uses that Q matrix to dequantize the data block.

Abstract: An adaptive demosaicing method interpolates images based on color edge detection and neighborhood voting. The adaptive demosaicing algorithm uses a voting scheme to determine the direction of interpolation at each missing luminance pixel location. Each color plane votes either horizontal or vertical based on a comparison between the horizontal and vertical components of the degree of change (i.e., gradient, Laplacian or other measure of the degree of change) in that color plane. Votes are counted from the neighborhood pixels as well as from measurements taken at the pixel location itself. Once the luminance plane is fully interpolated, the chrominance planes are filled in by simple bilinear or median interpolation of difference chrominance values. Enhancements to the adaptive demosaicing algorithm permit adaptive smoothing and sharpening.

Abstract: An image processing system and demosaicing method are provided to calculate estimated missing color sensor values in an image using a linear prediction from the raw color sensor value at the current pixel location. The raw image is divided into regions of sensor values, and the linear relations between color planes for each region are determined by a regression method that calculates the degree to which different color planes co-vary within each region The missing color sensor values per region are calculated as a scaled and shifted version of the raw color sensor values using linear regression coefficients determined from the local linear regression process.

Abstract: Two or more spatial filters are used in determining velocity based on speckle translation. A light source may be turned on, turned off, or both for a variable amount of time during operation. The velocity may then be determined with trend identification, correlation, recursive frequency estimation, or measurement bandwidth variation. A confidence level may also be calculated for the measured velocity, and the measured velocity reported or used only when the calculated confidence level meets or exceeds a given value.

Abstract: A digital image sensor comprising an array of pixels and a processor is provided. The array of pixels comprises a current pixel in a first color plane that is configured to produce a current sensor value, a first plurality of pixels in the first color plane that is configured to produce a first plurality of sensor values, and a second plurality of pixels in the second color plane that is configured to produce a second plurality of sensor values. The processor is configured to generate a plurality of estimate values using the first plurality of sensor values and a plurality of intensity ratios associated with the second plurality of sensor values, and the processor is configured to determine whether the current pixel is defective using the plurality of estimate values and the current sensor value.