Abstract: Method and apparatus for removing image artifacts from an image of a scene illuminated by a periodically varying light source such as a fluorescent light source. The image is represented by image data, and the method has the steps of determining a flicker function and processing the image data using the flicker function to remove the image artifacts from the image. The method and apparatus operate on data of a single image, do not require any additional input other than values of the flicker and frame periods, and do not require that the flicker be independently monitored. The method and apparatus is suitable for removing image artifacts from an image represented by image data collected by a CMOS image sensor utilizing a rolling shutter.

Abstract: A pair of CMOS image sensors is provided. One of the pair of CMOS image sensors is assigned as a master CMOS image sensor and the other is assigned as a slave CMOS image sensor. The slave CMOS image sensor is synchronized to the master CMOS image sensor during image data acquisition. In one embodiment, the master CMOS image sensor and the slave CMOS image sensor are connected to receive a control signal, which assigns the master CMOS image sensor as master and the slave CMOS image sensor as slave. In another embodiment, the master CMOS image sensor and slave CMOS image sensor are hardwired to assign the master and slave. In yet another embodiment, the data signals from the master CMOS image sensor and slave CMOS image sensor are interleaved.

Abstract: A method for exposure control which yields exposure settings just high enough to clip light sources and reflections from light sources in an image scene while allocating the majority of image sensor dynamic range to remaining objects in the image scene. Exposure control according to the present techniques includes determining a number of clipped pixels from an image scene for one or more of a set of possible exposures and determining a selected exposure from the possible exposures such that the possible exposures higher than the selected exposure increase the number and the possible exposures less than the selected exposure do not substantially decrease the number.

Abstract: A three-dimensional optical inspection system reconstructs a three-dimensional image of the shape of the surface of an at least partially specular object resident on a printed circuit board by capturing two or more two-dimensional images of the object under different illumination configurations. The diffuse reflection, as well as the specular reflection can be used to reconstruct the three-dimensional image using any reconstruction method, such as photometric stereo. The different illumination configurations can be achieved using an illumination source including light-emitting elements arranged in concentric circular arrays, in which each of the circular arrays is divided into sections. Each section is independently controlled to selectively activate the sections to illuminate the object in a pre-established illumination pattern.

Abstract: A system and method for reducing image lag in a complementary metal oxide semiconductor (CMOS) photodetector is disclosed. In one embodiment, the invention is a a method for reducing image lag in an array of complementary metal oxide semiconductor (CMOS) photodetectors by forward biasing the photodetectors during a first time period to charge charge traps in the photodetectors, and reverse biasing the photodetectors during a second time period to remove charge from the photodetectors except the charge trapped in the charge traps.

Abstract: A method and apparatus for improving image quality in a digital imaging device such as a digital video or still camera. A method for improving image quality of the device has steps of providing a digital image signal, and selecting a color corrector based, at least in part, on a signal-to-noise ratio of the digital image signal. The method and apparatus enables the image quality of an electronic output image output by the digital imaging device to be optimized over a wide range of signal values.

Abstract: An apparatus and method for reducing smear in electronic images utilizes estimated smear signals to remove components in the image signals of the electronic images that are attributable to the smear. The estimated smear signals correspond to the smear components of the image signals. The estimated smear signals are generated by collecting electrical charges in an electronic image sensor after an exposure period. The estimated smear signals may be generated in sequence to the acquisition of the image signals. Alternatively, the estimated smear signals may be generated in parallel to the acquisition of the image signals.

Abstract: An optical inspection system uses an illumination gradient to gradually spatially vary the intensity and/or specular characteristics of the illumination reflected from the surface of a specular object to determine surface gradients of the object. The surface gradients can be used to reconstruct a three-dimensional image of the object. The illumination gradient can be produced by an illumination apparatus that includes circular arrays of light-emitting elements. The illumination gradient can also be produced using an optical element that gradually alters the illumination intensity of the reflected illumination in accordance with the incidence characteristics of the reflected illumination on the optical element. The illumination gradient enables the use of numerous illumination angles to reduce error in estimated surface gradients without increasing imaging or processing time.

Abstract: A three-dimensional optical inspection system reconstructs a three-dimensional image of the shape of the surface of an at least partially specular object resident on a printed circuit board by capturing two or more two-dimensional images of the object under different illumination configurations. The diffuse reflection, as well as the specular reflection can be used to reconstruct the three-dimensional image using any reconstruction method, such as photometric stereo. The different illumination configurations can be achieved using an illumination source including light-emitting elements arranged in concentric circular arrays, in which each of the circular arrays is divided into sections. Each section is independently controlled to selectively activate the sections to illuminate the object in a pre-established illumination pattern.

Abstract: An apparatus such as a digital camera includes an image sensor array adapted to capture a scene into electrical values and a reference detector proximal to the sensor array for detecting illuminant intensities. The reference detector at least partially surrounds the image sensor array. The reference detector is read multiple times during the frame period in which the image sensor array captures a scene to detect illuminant intensities during the same frame period. Using the illuminant intensities, the phase and the amplitude of the flicker of the illuminant are extracted. Using the phase and the amplitude parameters, a flicker correction signal is synthesized. The flicker correction signal is used to correct the captured image data to reduce or eliminate adverse effects of flicker on the captured image.

Abstract: A system and method for reducing image lag in a complementary metal oxide semiconductor (CMOS) photodetector is disclosed. In one embodiment, the invention is a a method for reducing image lag in an array of complementary metal oxide semiconductor (CMOS) photodetectors by forward biasing the photodetectors during a first time period to charge charge traps in the photodetectors, and reverse biasing the photodetectors during a second time period to remove charge from the photodetectors except the charge trapped in the charge traps.

Abstract: An image sensor pixel has variable conversion gain to prevent overexposure of the pixel without reducing the exposure period. Under dim lighting conditions, the pixel operates with high conversion gain and is highly sensitive to light. When the incident light is bright, the pixel switches into a low conversion gain, low-sensitivity mode. The variable conversion gain is implemented by connecting a variable capacitive load in parallel with the photodiode of the image sensor pixel. When the incident light intensity exceeds a certain threshold, the variable capacitive load is increased to allow the photodiode to absorb more light. Likewise, the variable capacitive load is decreased when the incident light intensity is below a certain threshold.

Abstract: A method is provided for continuously monitoring for the presence or quantity of an analyte in a flowing liquid stream. The method involves binding an analyte-specific receptor species to the surface of a piezoelectric substrate, contacting the surface bound receptor species with the flowing liquid stream and quantitating the presence of the analyte. A novel apparatus for detecting the presence of an analyte in a liquid chromatography eluant is provided as well.

Abstract: A method for dark current subtraction which enables a dark frame to be reused for dark current subtraction for multiple image frames. The dark frame is reused by scaling it according to changes in the dark current levels associated with the dark frame and the image frames.

Abstract: A method, system and program product for providing automatic focus adjustment for an image device, comprising the steps of: differentiating an image along some axis to obtain a difference image; computing a variance of the difference image; determining a noise contribution to the variance; subtracting the noise contribution from the variance; using the adjusted noise variance as a factor in making the automatic focus adjustment. In a preferred embodiment, the variance is normalized, and the noise contribution is determined by determining the shot noise and the read noise.

Abstract: A method and apparatus for improving image quality in a digital imaging device such as a digital video or still camera. A method for improving image quality of the device has steps of providing a digital image signal, and selecting a color corrector based, at least in part, on a signal-to-noise ratio of the digital image signal. The method and apparatus enables the image quality of an electronic output image output by the digital imaging device to be optimized over a wide range of signal values.

Abstract: Method and apparatus for removing image artifacts from an image of a scene illuminated by a periodically varying light source such as a fluorescent light source. The image is represented by image data, and the method has the steps of determining a flicker function and processing the image data using the flicker function to remove the image artifacts from the image. The method and apparatus operate on data of a single image, do not require any additional input other than values of the flicker and frame periods, and do not require that the flicker be independently monitored. The method and apparatus is suitable for removing image artifacts from an image represented by image data collected by a CMOS image sensor utilizing a rolling shutter.

Abstract: A method for processing a charge couple device (CCD) image is provided comprising the steps of obtaining charge packets in response to light, processing the charge packets into an analog signal, converting the analog signal to a digital signal, and filtering the digital signal with a finite impulse response (FIR) filter.

Abstract: A method and device for improving the generation of the focus signal in the auto-focus system of a camera.

Abstract: An apparatus and method for reducing smear in electronic images utilizes estimated smear signals to remove components in the image signals of the electronic images that are attributable to the smear. The estimated smear signals correspond to the smear components of the image signals. The estimated smear signals are generated by collecting electrical charges in an electronic image sensor after an exposure period. The estimated smear signals may be generated in sequence to the acquisition of the image signals. Alternatively, the estimated smear signals may be generated in parallel to the acquisition of the image signals.