Abstract: Systems and methods for processing YCC image data provided. In one example, an electronic device includes memory to store image data in RGB or YCC format and a YCC image processing pipeline to process the image data. The YCC image processing pipeline may include receiving logic configured to receive the image data in RGB or YCC format and color space conversion logic configured to, when the image data is received in RGB format, convert the image data into YCC format. The YCC image processing logic may also include luma sharpening and chroma suppression logic; brightness, contrast, and color adjustment logic; gamma logic; chroma decimation logic; scaling logic; and chromanoise reduction logic.

Abstract: Systems and methods for correcting green channel non-uniformity (GNU) are provided. In one example, GNU may be corrected using energies between the two green channels (Gb and Gr) during green interpolation processes for red and green pixels. Accordingly, the processes may be efficiently employed through implementation using demosaic logic hardware. In addition, the green values may be corrected based on low-pass-filtered values of the green pixels (Gb and Gr). Additionally, green post-processing may provide some defective pixel correction on interpolated greens by correcting artifacts generated through enhancement algorithms.

Abstract: Systems and methods for correcting geometric distortion are provided. In one example, an electronic device may include an imaging device, which may obtain image data of a first resolution, and geometric distortion and scaling logic. The imaging device may include a sensor and a lens that causes some geometric distortion in the image data. The geometric distortion correction and scaling logic may scale and correct for geometric distortion in the image data by determining first pixel coordinates in uncorrected or partially corrected image data that, when resampled, would produce corrected output image data at second pixel coordinates. The geometric distortion correction and scaling logic may resample pixels around the image data at the first pixel coordinates to obtain the corrected output image data at the second pixel coordinates. The corrected output image data may be of a second resolution.

Abstract: Systems and methods for processing raw image data are provided. One example of such a system may include memory to store image data in raw format from a digital imaging device and an image signal processor to process the image data. The image signal processor may include data conversion logic and a raw image processing pipeline. The data conversion logic may convert the image data into a signed format to preserve negative noise from the digital imaging device. The raw image processing pipeline may at least partly process the image data in the signed format. The raw image processing pipeline may also include, among other things, black level compensation logic, fixed pattern noise reduction logic, temporal filtering logic, defective pixel correction logic, spatial noise filtering logic, lens shading correction logic, and highlight recovery logic.

Abstract: Systems and methods for local tone mapping are provided. In one example, an electronic device includes an electronic display, an imaging device, and an image signal processor. The electronic display may display images of a first bit depth, and the imaging device may include an image sensor that obtains image data of a higher bit depth than the first bit depth. The image signal processor may process the image data, and may include local tone mapping logic that may apply a spatially varying local tone curve to a pixel of the image data to preserve local contrast when displayed on the display. The local tone mapping logic may smooth the local tone curve applied to the intensity difference between the pixel and another nearby pixel exceeds a threshold.

Abstract: The present disclosure generally relates to systems and methods for image data processing. In certain embodiments, an image processing pipeline may be configured to receive a frame of the image data having a plurality of pixels acquired using a digital image sensor. The image processing pipeline may then be configured to determine a first plurality of correction factors that may correct each pixel in the plurality of pixels for fixed pattern noise. The first plurality of correction factors may be determined based at least in part on fixed pattern noise statistics that correspond to the frame of the image data. After determining the first plurality of correction factors, the image processing pipeline may be configured to configured to apply the first plurality of correction factors to the plurality of pixels, thereby reducing the fixed pattern noise present in the plurality of pixels.

Abstract: Temporally filtering raw image data may include a temporal filter that determines a spatial location of a current pixel and identifies at least one collocated reference pixel from a previous frame. A motion delta value is determined based upon the current pixel and its collocated reference pixel. An index is determined based upon the motion delta value and a motion history value corresponding to the current pixel from the previous frame. Using the index, a first filtering coefficient may be selected from a motion table. Then an attenuation factor may be selected from a luma table based upon the value of the current pixel, and a second filtering coefficient may be determined based upon the selected attenuation factor and the first filtering coefficient. The temporally filtered output value corresponding to the current pixel may then be based upon the second filtering coefficient, the current pixel, and the collocated reference pixel.

Abstract: Certain aspects of this disclosure relate to an image signal processing system that includes a flash controller that is configured to activate a flash device prior to the start of a target image frame by using a sensor timing signal. In one embodiment, the flash controller receives a delayed sensor timing signal and determines a flash activation start time by using the delayed sensor timing signal to identify a time corresponding to the end of the previous frame, increasing that time by a vertical blanking time, and then subtracting a first offset to compensate for delay between the sensor timing signal and the delayed sensor timing signal. Then, the flash controller subtracts a second offset to determine the flash activation time, thus ensuring that the flash is activated prior to receiving the first pixel of the target frame.

Abstract: Various techniques are disclosed for processing statistics data in an image signal processor (ISP). In one embodiment, a statistics collection engine may be implemented in a front-end processing unit of the ISP, such that statistics are collected prior to processing by an ISP pipeline downstream from the front-end processing unit. In one embodiment, the statistics collection engine may be configured to acquire statistics relating to auto white-balance, auto-exposure, and auto-focus, as well as flicker detection. Collected statistics may be output to a memory and used by the ISP to process acquired image data.

Abstract: Various techniques for applying binning compensation filtering to binned raw image data acquired by an image sensor are provided. In one embodiment, a binning compensation filter (BCF) includes separate digital differential analyzers (DDA) for vertical and horizontal scaling. A current position of an output pixel is determined by incrementing the DDA based upon a step size. Using the known output pixel position, a center source input pixel and an index corresponding to the between-pixel fractional position of the output pixel position relative to the input pixels may be selected for filtering. Using the selected center input pixel, one or more same-colored neighboring source pixels may be selected. The number of selected source pixels may depend on the number of taps used by the scaling logic, and may depend on whether horizontal or vertical scaling is being applied.

Abstract: Certain embodiments of the present disclosure provide a flexible memory input/output controller that is configured to the storing and reading of multiple types of pixels and pixel memory formats. For instance, the memory I/O controller may support the storing and reading of raw image pixels at various bits of precision, such as 8-bit, 10-bit, 12-bit, 14-bit, and 16-bit. Pixel formats that are unaligned with memory bytes (e.g., not being a multiple of 8-bits) may be stored in a packed manner. The memory I/O controller may also support various formats of RGB pixel sets and YCC pixel sets.

Abstract: The present disclosure provides techniques relates to the implementation of a raw pixel processing unit using a set of line buffers. In one embodiment, the set of line buffers may include a first subset and second subset. Various logical units of the raw pixel processing unit may be implemented using the first and second subsets of line buffers in a shared manner. For instance, in one embodiment, defective pixel correction and detection logic may be implemented using the first subset of line buffers. The second subset of line buffers may be used to implement lens shading correction logic, gain, offset, and clamping logic, and demosaicing logic. Further, noise reduction may also be implemented using at least a portion of each of the first and second subsets of line buffers.

Abstract: Various techniques are provided for processing image data acquired using a digital image sensor. In accordance with aspects of the present disclosure, one such technique may relate to the processing of image data in a system that supports multiple image sensors. In one embodiment, the image processing system may include control circuitry configured to determine whether a device is operating in a single sensor mode (one active sensor) or a dual sensor mode (two active sensors). When operating in the single sensor mode, data may be provided directly to a front-end pixel processing unit from the sensor interface of the active sensor. When operating in a dual sensor mode, the image frames from the first and second sensors are provided to the front-end pixel processing unit in an interleaved manner. For instance, in one embodiment, the image frames from the first and second sensors are written to a memory, and then read out to the front-end pixel processing unit in an interleaved manner.

Abstract: Certain aspects of this disclosure relate to an image signal processing system that includes a flash controller that is configured to activate a flash device prior to the start of a target image frame by using a sensor timing signal. In one embodiment, the flash controller receives a delayed sensor timing signal and determines a flash activation start time by using the delayed sensor timing signal to identify a time corresponding to the end of the previous frame, increasing that time by a vertical blanking time, and then subtracting a first offset to compensate for delay between the sensor timing signal and the delayed sensor timing signal. Then, the flash controller subtracts a second offset to determine the flash activation time, thus ensuring that the flash is activated prior to receiving the first pixel of the target frame.

Abstract: Systems and methods are disclosed for applying spatial filtering to raw image data. For example, a spatial filter may identify an n x n block of pixels from an image frame. The spatial filter has filter taps, each corresponding to one of the pixels of the n x n block. Pixel difference values between the input pixel and each of the neighboring pixels in the n x n block may be determined. Attenuation factors may be determined based on the pixel differences and brightness of the input pixel. Applying the attenuation factors to their respective filtering taps may produce attenuated filtering coefficients that are used to obtain filtered pixel values. By normalizing the sum of the filtered pixel values using the sum of the attenuated filtering coefficients, a spatially filtered output value corresponding to the current input pixel (e.g., located at the center of the n x n block) may be determined.

Abstract: Various techniques for lens shading correction are provided. In one embodiment, the location of a current pixel is determined relative to a gain grid having a plurality of grid points distributed in horizontal and vertical directions. If the location of the current pixel corresponds to a grid point, a lens shading gain associated with that grid point is applied to the current pixel. If the location of the current pixel is between four grid points, bi-linear interpolation is applied to the four grid points to determine an interpolated lens shading gain. In another embodiment, a radial gain grid may be provided, and lens shading gains may be interpolated based upon grid points neighboring a current pixel in the radial and angular directions. In a further embodiment, a radial lens shading gain is determined by determining a radial distance from the center of the image to the current pixel and multiplying the radial distance by a global gain parameter based upon the color of the current pixel.

Abstract: A method for encoding a picture is disclosed. The method generally includes the steps of (A) generating at least one respective macroblock statistic from each of a plurality of macroblocks in the picture, (B) generating at least one global statistic from the picture and (C) generating a respective macroblock quantization parameter for each of the macroblocks based on both (i) the at least one respective macroblock statistic and (ii) said at least one global statistic.

Abstract: A device, method, computer useable medium, and processor programmed to automatically generate tone mapping curves in a digital camera based on image metadata are described. By examining image metadata from a digital camera's sensor, such as the light-product, one can detect sun-lit, high-light, and low-light scenes. Once the light-product value has been calculated for a given image, a tone mapping curve can automatically be generated within the sensor and adjusted appropriately for the scene based on predetermined parameters. Further, it has been determined that independently varying the slopes of the tone mapping curve at the low end (S0) and high end (S1) of the curve results in more visually appealing images. By dynamically and independently selecting S0 and S1 values based on image metadata, more visually pleasing images can be generated.

Abstract: Various techniques are provided herein for processing raw image data acquired using a digital image sensor in an image processing pipeline of an image signal processing system. In one embodiment, the image processing pipeline may first process the raw image data (e.g., Bayer image data) for the detection and correction of defective pixels. Next, the image processing pipeline may process the raw image data to reduce noise. Thereafter, the image processing pipeline may correct lens shading distortion in the raw image data and, subsequently, apply a demosaicing algorithm to convert the raw image data into full color image data (e.g., RGB image data). The color image data may be further processed by the image processing pipeline to correct color and gamma properties prior to being converted into a luma and chroma color space (e.g., YCbCr color space).

Abstract: A camera comprising a first circuit and a second circuit. The first circuit may be configured to perform image signal processing using encoding related information. The second circuit may be configured to encode image data using image signal processing related information. The first circuit may be further configured to pass the image signal processing related information to the second circuit. The second circuit may be further configured to pass the encoding related information to the first circuit. The second circuit may be further configured to modify one or more motion estimation processes based upon the information from the first circuit.