Methods of calibrating a linear-logarithmic image sensor pixel include performing a reset of the pixel in advance of establishing a leakage current between a photodiode and a floating diffusion region of the pixel. A first voltage of the floating diffusion region is then read through a source follower and selection transistor, after the leakage is terminated. A step is then performed to transfer charge between the photodiode and the floating diffusion region of the pixel so that a voltage of a cathode of the photodiode is increased. Thereafter, a second voltage of the floating diffusion region is read. The first and second read voltages are then used to perform a calibration operation. These steps may be repeated to establish another leakage current of different duration/magnitude and yield third and fourth read voltages, which support further calibration.

A method of correcting errors in the output of an image detector is disclosed. The method comprises measuring an output signal (V.sub.m) of a capacitor (C.sub.sh) holding a voltage corresponding to a signal detected by the image detector; comparing the value of output signal (V.sub.m) to the value of the previously measured output signal (V.sub.m−1) of the capacitor (C.sub.sh); calculating the error in the output signal (V.sub.m) using a predetermined correction factor and the difference between the value of the output signal (V.sub.m) and the value of the previously measured output signal (V.sub.m−1); and providing a corrected output value (V.sub.crt) in accordance with the calculated error. Detectors, methods of calibrating detectors, image correction apparatus and guidance systems comprising the detectors are also disclosed.

Example embodiments relate to microlensing for real-time sensing of stray light. An example device includes an image sensor that includes a plurality of light-sensitive pixels. The device also includes a first lens positioned over a first subset of light-sensitive pixels selected from the plurality of light-sensitive pixels. Further, the device includes a controller. The controller is configured to determine a first angle of incidence of a first light signal detected by the first subset of light-sensitive pixels. The controller is also configured to, based on the first determined angle of incidence, determine an amount of stray light incident on the image sensor.

A method of defect pixel correction, includes, receiving at least one center pixel signal in a plurality of frames, receiving a plurality of neighboring pixel signals adjacent the center pixel in the plurality of frames, determining a brightness of the center pixel signal, determining the brightness of the plurality of neighboring pixel signals, determining if the brightness of the center pixel signal exceeds a wounded pixel threshold of the plurality of neighboring pixel signals, determining a location of the center pixel having the brightness greater than the wounded pixel threshold in at least one frame, determining a number of reoccurrences of the center pixel having the brightness greater than the wounded pixel threshold, determining if the number of reoccurrences exceeds a defect pixel threshold and updating the at least one center pixel signal to a mean of the plurality of neighboring pixel signals.

An image sensor may include an array of image pixels arranged in rows and columns. Each column of pixels may be coupled to current source transistors and capacitance cancellation circuitry. The capacitance cancellation circuitry may include capacitors, a common source amplifier transistor, an autozero switch, a switch for selectively deactivating at least one of the capacitors during sample-and-hold reset and sample-and-hold signal operations.

An exemplary method implements fixed pattern noise compensation for captured visual images of a moving scene. A current X-by-Y frame of image values captured by a camera is stored in memory where the magnitude of each image value represents a light level associated with a respective X-by-Y position in the frame. A moving average value for each image value over a number of X-by-Y frames is determined where the moving average value for each X-by-Y image value represents a level of fixed pattern noise for the moving scene. X-by-Y frames with fixed pattern noise compensated image values are generated based on subtracting from each image value of the current X-by-Y frame the corresponding moving average value.

A photoelectric conversion device includes a plurality of pixels, a plurality of output lines, to which signals from corresponding pixels are output, respectively, an amplification unit arranged corresponding to each of the plurality of output lines and configured to amplify a signal output to a corresponding output line, a comparison unit arranged corresponding to each of the plurality of output lines and having a first input terminal and a second input terminal, a signal corresponding to an output of the amplification unit being input to the first input terminal, a reference signal being input to the second input terminal, and a switch connecting nodes of the plurality of output lines. During a period before an offset clamping operation is completed, the switch is turned on.

A photoelectric conversion device according to an embodiment of the present disclosure includes a calculation unit configured to calculate an initial value of each of a plurality of first correction components based on a first pixel value read out from the first region, update each of the plurality of the first correction components based on a second pixel value read out from the second region and a predetermined second correction component, and calculate the correction value using the updated first correction component and the second correction component.

Fluorescence imaging with reduced fixed pattern noise is disclosed. A method includes actuating an emitter to emit a plurality of pulses of electromagnetic radiation and sensing reflected electromagnetic radiation resulting from the plurality of pulses of electromagnetic radiation with a pixel array of an image sensor. The method includes reducing fixed pattern noise in an exposure frame by subtracting a reference frame from the exposure frame. The method is such that at least a portion of the plurality of pulses of electromagnetic radiation emitted by the emitter comprises electromagnetic radiation having a wavelength from about 795 nm to about 815 nm.

An image sensor for reducing channel variation and an image processing system including the same. The image sensor includes first to m.sup.th pixels (m≧2), each of which is connected to a corresponding column line from among first to m.sup.th column lines and is configured to output a respective pixel signal.’ The image sensor further includes first to m.sup.th bias circuits, each of which is connected to a corresponding column line from among the first to m.sup.th column lines and is configured to fix a voltage of the corresponding column line to a bias voltage when a column line-specific pixel is not selected to output the respective pixel signal. An analog-to-digital converter in the image sensor is configured to convert the pixel signals into digital signals.