Abstract: An image sensor may include an array of image pixels arranged according to a predetermined pattern. A 3-by-3 pixel sub-sampling method is provided that supports a high-speed sub-resolution video mode. The 3-by-3 sub-sampling method may involve organizing the image pixel array into groups, each of which contains a 3-by-3 array of nine pixels. Image pixels at the four corners of each group may be sampled and combined to form a final output. Final outputs produced from each group may form a sub-sampled array that is used by the sub-resolution video mode.

Abstract: An imager may include an array of pixels. The pixel array may be arranged in rows and columns. Each pixel of the pixel array may include a photodiode that is coupled to a floating diffusion region by a transfer gate. A source-follower transistor may be coupled between the floating diffusion region and a pixel output node. The imager may include ramp circuitry that provides a ramp signal to the floating diffusion region. A capacitor interposed between the ramp circuitry and the floating diffusion region may be used in conveying the ramp signal to the floating diffusion region. The pixel may be coupled to a comparator that is implemented using separate circuitry or may include portions of the pixel.

Abstract: The invention describes a solid-state CMOS image sensor array and discloses image sensor array pixels with global and rolling shutter capabilities that utilize multiple BCMD transistors for a single photodiode, for charge storage and sensing. Thus, the valuable pixel area saved by employing the BCMD transistor for charge storage and sensing is used by placing several BCMD transistors coupled to one photodiode. This increases the Dynamic Range (DR) of the sensor, since the same photodiode can integrate charge for different integration times, both long and short. This allows sensing of two different image signals from a single pixel without saturation, a low level signal with long integration time followed by a high level signal with short integration time. The signal processing circuits located at the periphery of the array can then process these signals into a single Wide Dynamic Range (WDR) output.

Abstract: Imaging systems with image sensors and image processing circuitry are provided. The image processing circuitry may identify motion and perform autofocus (e.g., continuous autofocus) using images captured by an image sensor. Auto exposure metrics such as average luminance values and autofocus statistics such as sharpness scores may be calculated for each image. The auto exposure metrics may be used to calculate motion scores and identify directional motion between a series of captured images. The motion scores may be used with the sharpness scores to determine when to perform autofocus functions such as when to refocus a lens for a continuous autofocus application. For example, the motion scores may be monitored to identify motion that exceeds a given magnitude and duration. After identification of motion, motion scores and sharpness scores may be used to determine when a given scene has stabilized and when the lens should be refocused.

Abstract: Electronic devices may include image sensors. Image sensors may be used to capture images having rows of long-exposure image pixel values that are interleaved with rows of short-exposure image pixel values. The long-exposure and short-exposure values in each interleaved image frame may be interpolated to form interpolated values. A combined long-exposure image and a combined short-exposure image may be generated using the long-exposure and the short-exposure values from the interleaved image frames and the interpolated values from a selected one of the interleaved image frames. The combined long-exposure and short-exposure images may each include image pixel values from either of the interleaved image frames in a non-motion edge region and image pixel values based only on the image pixel values or the interpolated values from the selected one of the interleaved images in a motion or non-edge region. High-dynamic-range images may be generated using the combined long-exposure and short-exposure images.

Abstract: An image sensor may be provided that includes an image pixel array, analog column circuitry and digital column circuitry. The digital column circuitry may extract a systematic analog signal offset from data received from the analog column circuitry. The digital column circuitry may generate analog signal offset correction values based on the systematic analog signal offsets and provide the analog signal offset correction values to the analog column circuitry. The analog column circuitry may remove signal offsets from subsequently read out image data from the image pixel array using the analog signal offset correction values provided by the digital column circuitry. The image pixel array may include image pixels having color filters of various colors. The digital column circuitry may generate analog signal offset correction values corresponding to each of the various colors.

Abstract: Apparatus and a method for generating a rectified image. First pixel information corresponding to a first image is received from a first imager. Second pixel information corresponding to a second image is received from a second imager. A plurality of facial feature points of a portrait in each of the first and second images are identified. A fundamental matrix is generated based on the detected facial features. An essential matrix is generated based on the fundamental matrix. Rotational and translational information corresponding to the first and second imagers are generated based on the essential matrix. The rotational and translational information are applied to at least one of the first and second images to generate at least one rectified image.

Abstract: An image sensor may include an image pixel array. The image sensor may be provided with automatic conversion gain selection on a pixel-by-pixel basis to produce a high-dynamic-range image. Each image pixel may include a capacitor and a conversion gain transistor coupled in series between a power supply line and a floating diffusion node. The conversion gain transistor may be coupled to a control line through a gating transistor. The gating transistor may have a gate connected to a row select line. The image pixel may have an output line that is coupled to a column amplifier and a comparator. The column amplifier may generate a difference voltage based on reset and image signals. The comparator may compare the difference voltage with a predetermined threshold to determine whether to place the selected pixel in a high or low conversion gain mode.

Abstract: An electronic device may have a camera module and a host subsystem. The camera module may include a camera sensor and associated image processing and data formatting circuitry. The image processing and data formatting circuitry may include an image processor that produces unscaled images frames using data from the camera sensor. Unscaled image frames may be processed in multiple paths between the image processor and the host subsystem such as a path that includes an image compression circuit block, a parallel path that includes a preview scaler, and a parallel path that includes a multiframe scaler and a frame buffer and multiframe image processor circuitry. The multiframe scaler may scale unscaled frames for buffering and processing by the frame buffer and multiframe image processor circuitry to produce analysis results. The analysis results may be appended to compressed unscaled image frames sent to the host subsystem.

Abstract: An electronic device may have a stereoscopic camera module with left and right image sensors separated by a stereo base line. The camera module may have an adjustable convergence such that the position at which objects are captured by the left and right image sensors with zero horizontal disparity can be moved closer to and farther from the electronic device. The convergence of the camera module may be adjusted such that a region of interest or an object (i.e., subject) is captured with minimal horizontal disparity. With arrangements of this type, conflicts between accommodation (e.g., the location of a display) and convergence (e.g., the perceived location of the region of interest or subject either behind, on the plane of, or in front of a display) may be reduced.

Abstract: An imager includes an array of pixels arranged in rows and a control circuit for sequentially capturing first and second image frames from the array of pixels. The control circuit is configured to sequentially capture first and second pairs of adjacent rows of pixels during first and second exposure times, respectively, when capturing the first image frame. The control circuit is also configured to sequentially capture first and second pairs of adjacent rows of pixels during second and first exposure times, respectively, when capturing the second image frame. The first exposure times during the first and second frames are of similar duration; and the second exposure times during the first and second frames are of similar duration. The control circuit is configured to detect motion of an object upon combining the first and second image frames and, then, correct for the motion of the object.

Abstract: A backside illuminated image sensor with an array of image sensor pixels is provided. Each image pixel may include a photodiode and associated pixel circuits formed in a front surface of a semiconductor substrate. Silicon inner microlenses may be formed on a back surface of the semiconductor substrate. In particular, positive inner microlenses may be formed over the photodiodes, whereas negative inner microlenses may be formed over the associated pixel circuits. Buried light shielding structures may be formed over the negative inner microlenses to prevent pixel circuitry that is formed in the substrate between two neighboring photodiodes from being exposed to incoming light. The buried light shielding structures may be lined with absorptive antireflective coating material to prevent light from being reflected off the surface of the buried light shielding structures.

Abstract: Imaging systems may be provided with stacked-chip image sensors. A stacked-chip image sensor may include a vertical chip stack that includes an array of image pixels, analog control circuitry and storage and processing circuitry. The array of image pixels, the analog control circuitry, and the storage and processing circuitry may be formed on separate, stacked semiconductor substrates or may be formed in a vertical stack on a common semiconductor substrate. The image pixel array may be coupled to the control circuitry using vertical metal interconnects. The control circuitry may route pixel control signals and readout image data signals over the vertical metal interconnects. The control circuitry may provide digital image data to the storage and processing circuitry over additional vertical conductive interconnects coupled between the control circuitry and the storage and processing circuitry. The storage and processing circuitry may be configured to store and/or process the digital image data.

Abstract: A global shutter pixel cell includes a serially connected anti-blooming (AB) transistor, storage gate (SG) transistor and transfer (TX) transistor. The serially connected transistors are coupled between a voltage supply and a floating diffusion (FD) region. A terminal of a photodiode (PD) is connected between respective terminals of the AB and the SG transistors; and a terminal of a storage node (SN) diode is connected between respective terminals of the SG and the TX transistors. A portion of the PD region is extended under the SN region, so that the PD region shields the SN region from stray photons. Furthermore, a metallic layer, disposed above the SN region, is extended downwardly toward the SN region, so that the metallic layer shields the SN region from stray photons. Moreover, a top surface of the metallic layer is coated with an anti-reflective layer.

Abstract: An image sensor may be provided in which a pixel array includes imaging pixels and application-specific pixels. The application-specific pixels may include depth-sensing pixels, infrared imaging pixels, or other types of application-specific pixels. A color filter array may be formed over the pixel array. The color filter array may include Bayer color filter array formed over the imaging pixels. The color filter array may also include a plurality of green color filter elements formed over the application-specific pixels. Barrier structures may be interposed between imaging pixels and application-specific pixels. The barrier structures may be configured to reduce or eliminate optical crosstalk between imaging pixels and adjacent application-specific pixels. The barrier structures may include an opaque photodefinable material such as black or blue photodefinable material that may be configured to filter out wavelength bands of interest.

Abstract: Multiple-exposure high dynamic range image processing may be performed that filters pixel values that are distorted by blooming from nearby saturated pixels. Pixel values that are near saturated pixels may be identified as pixels that may be affected by blooming. The contributions from those pixels may be minimized when producing a final image. Multiple-exposure images may be linearly combined to produce a final high dynamic range image. Pixel values that may be distorted by blooming may be given less weight in the linear combination.

Abstract: Imaging devices may include processing circuitry, a lens, and an array of image sensor pixels and reference pixels. The array may receive direct image light and stray light from the lens. The image sensor pixels may include clear color filter elements and the reference pixels may include opaque color filter elements. The opaque color filter elements may block direct image light from being captured by the reference pixels. The image sensor pixels may generate pixel values in response to the direct image light and the stray light whereas the reference pixels may generate reference pixel values in response to the stray light. The processing circuitry may mitigate stray light effects such as local flare and veiling glare within the imaging system by adjusting the pixel values based on the reference pixel values. The imaging system may be calibrated in a calibration system for generating stray light calibration data.

Abstract: An imaging system may include image sensor pixels, converter circuitry, denoising circuitry, dark current subtraction circuitry, and storage and processing circuitry. The image sensor pixels may generate analog image signals and the converter circuitry may convert the analog image signals into digital pixel values. The denoising circuitry may generate denoised pixel values based on the digital pixel values. The dark current subtraction circuitry may subtract a dark current value from the denoised pixel values. The image sensor pixels and converter circuitry may generate pixel values in multiple color channels. The image sensor pixels may include clear color filter elements for generating clear pixel values. The storage and processing circuitry may determine different black pedestal values for each color channel and may add the black pedestal values to the pixel values from the corresponding color channel to mitigate pixel value clipping in a final image generated by the imaging system.

Abstract: An imaging system may include a camera module with an image sensor having an array of image sensor pixels. The image sensor may include a substrate having an array of photodiodes, an array of microlenses formed over the array of photodiodes, and an array of color filter elements interposed between the array of microlenses and the array of photodiodes. The color filter elements may be separated from each other by color filter barriers. Each color filter barrier may include an upper portion formed from dielectric material and a lower portion formed from metal. The metal portion of each color filter barrier may form a crosstalk reduction structure that prevents stray light from passing from one pixel to an adjacent pixel. The color filter barriers may have a grid shape with an array of openings. The color filter elements may be deposited in the openings.

Abstract: Electronic devices may include super-resolution imaging systems for capturing multiple relatively low-resolution images and combining the captured images to form a high-resolution image. The imaging system may include image sensors configured to capture information above the Nyquist frequency of the image sensor by providing each image sensor pixel in an array of image sensor pixels with structures for reducing the size of the clear pixel aperture below the size of the image sensor pixel. The structures may be configured to pass light that is incident on a central region of the image sensor pixel to a photo-sensitive element through a color filter element and to reject light that is incident on a surrounding edge region. The structures may include a microlens configured to reject light that is incident on the edge region or a combination of a microlens and masking structures. Masking structures may be absorbing, reflecting, or interfering structures.