Reduction of line banding image artifacts

    公开(公告)号:US11037272B2

    公开(公告)日:2021-06-15

    申请号:US16381312

    申请日:2019-04-11

    Applicant: Apple Inc.

    Abstract: Embodiments of the present disclosure relate to reducing line banding artifacts in raw image data. If the same line of pixel sensors (e.g., in a row) in an image sensor includes a subset of pixel sensors that receive bright light and another subset of pixel sensors that receive low light, line banding artifacts may appear in the capture raw image data. To reduce or eliminate the line banding artifacts, the raw image data is normalized by adding offset values to its pixel values. The offset values are determined from the pixel values obtained from masked pixel sensors on one or both sides of the image sensor.

    Directional bilateral filtering with improved noise reduction along edges

    公开(公告)号:US10825154B2

    公开(公告)日:2020-11-03

    申请号:US16358117

    申请日:2019-03-19

    Applicant: Apple Inc.

    Abstract: Embodiments relate to a bilateral filter circuit for directional filtering of an image. The directional bilateral filter circuit determines an edge direction and a weight for the edge direction by processing differences between pixel values of pixels in a first block of pixels in the image. The bilateral filter circuit determines non-directional taps for pixels in a second block by processing pixel locations, and determines directional taps by processing differences between pixel values, gradient information for the second block and the edge direction. The bilateral filter circuit determines final filter taps for pixels in the second block by blending corresponding non-directional taps and directional taps using the weight. The bilateral filter circuit obtains a pixel value of a filtered image by multiplying the final filter taps to corresponding pixel values of the pixels in the second block and adding the multiplied values.

    BIASING A NOISE FILTER TO PRESERVE IMAGE TEXTURE

    公开(公告)号:US20200342579A1

    公开(公告)日:2020-10-29

    申请号:US16393892

    申请日:2019-04-24

    Applicant: Apple Inc.

    Abstract: Embodiments relate to biasing an image noise filter to reduce edge and texture blurring of image data. Pixel values used to determine photometric coefficients for a bilateral filter are modified by offset values. The offset value for a pixel value is determined by applying a high pass filter to the pixel (referred to as the center pixel) and neighboring pixels of the center pixel. By adding the offset value to the center pixel value, the pixel value difference between the neighboring pixels and the center pixel becomes smaller for pixels on the same side of an edge as the center pixel. Thus, pixels on the same side of the edge get more weight in the bilateral noise filter. Conversely, pixels on the opposite side of the edge as the center pixel get less weight in the bilateral filter. As a result, the biased bilateral filter reduces blurring of edges and increases preservation of texture in the image data.

    REDUCTION OF LINE BANDING IMAGE ARTIFACTS
    24.
    发明申请

    公开(公告)号:US20200327644A1

    公开(公告)日:2020-10-15

    申请号:US16381312

    申请日:2019-04-11

    Applicant: Apple Inc.

    Abstract: Embodiments of the present disclosure relate to reducing line banding artifacts in raw image data. If the same line of pixel sensors (e.g., in a row) in an image sensor includes a subset of pixel sensors that receive bright light and another subset of pixel sensors that receive low light, line banding artifacts may appear in the capture raw image data. To reduce or eliminate the line banding artifacts, the raw image data is normalized by adding offset values to its pixel values. The offset values are determined from the pixel values obtained from masked pixel sensors on one or both sides of the image sensor.

    AUTO-FOCUS ENGINE ARCHITECTURE FOR IMAGE SIGNAL PROCESSOR

    公开(公告)号:US20200320661A1

    公开(公告)日:2020-10-08

    申请号:US16376414

    申请日:2019-04-05

    Applicant: Apple Inc.

    Abstract: Embodiments relate to image signal processors (ISP) that include one or more auto-focus circuits. Each of the auto-focus circuits may be connected to an image sensor and may be separate from a statistics circuit and other image processing pipelines of the ISP. An image sensor may include one or more focus pixels that are used to generate data for auto-focusing. The auto-focus circuit may extract the focus pixel values and generate a signal to control the lens position of the image sensor. Each image sensor may include a separate auto-focus circuit. When other image processing pipelines of the ISP are processing the image data from one image sensor, the auto-focus circuit for another image sensor may continue to generate focus signals that control the lens position of the other image sensor. The other image sensor may be in standby but may continue to remain in focus.

    DIRECTIONAL BILATERAL FILTERING WITH IMPROVED NOISE REDUCTION ALONG EDGES

    公开(公告)号:US20200302580A1

    公开(公告)日:2020-09-24

    申请号:US16358117

    申请日:2019-03-19

    Applicant: Apple Inc.

    Abstract: Embodiments relate to a bilateral filter circuit for directional filtering of an image. The directional bilateral filter circuit determines an edge direction and a weight for the edge direction by processing differences between pixel values of pixels in a first block of pixels in the image. The bilateral filter circuit determines non-directional taps for pixels in a second block by processing pixel locations, and determines directional taps by processing differences between pixel values, gradient information for the second block and the edge direction. The bilateral filter circuit determines final filter taps for pixels in the second block by blending corresponding non-directional taps and directional taps using the weight. The bilateral filter circuit obtains a pixel value of a filtered image by multiplying the final filter taps to corresponding pixel values of the pixels in the second block and adding the multiplied values.

    IMAGE STATISTICS FOR MOTION DETECTION
    27.
    发明申请

    公开(公告)号:US20200053377A1

    公开(公告)日:2020-02-13

    申请号:US16100772

    申请日:2018-08-10

    Applicant: Apple Inc.

    Abstract: Embodiments of the present disclosure relate to generating motion vectors. An image signal processor includes a statistics circuit and a vector correlation analysis circuit. The statistics circuit determines image statistics such as vectors representing sums of pixel values of rows or columns of blocks of an image. Additionally, the statistics circuit may mix or aggregate sums of multiple color components. The vector correlation analysis performs cross-correlation between vectors of a current image and reference vectors of a prior image to determine cross-correlation scores. The vector correlation analysis generates a motion vector by identifying shifts in horizontal and vertical directions corresponding to peak values of cross-correlation scores.

    MULTI-RATE PROCESSING FOR IMAGE DATA IN AN IMAGE PROCESSING PIPELINE
    29.
    发明申请
    MULTI-RATE PROCESSING FOR IMAGE DATA IN AN IMAGE PROCESSING PIPELINE 有权
    图像处理流程中图像数据的多速率处理

    公开(公告)号:US20170061567A1

    公开(公告)日:2017-03-02

    申请号:US14836915

    申请日:2015-08-26

    Applicant: APPLE INC.

    Abstract: An image processing pipeline may process image data at multiple rates. A stream of raw pixel data collected from an image sensor for an image frame may be processed through one or more pipeline stages of an image signal processor. The stream of raw pixel data may then be converted into a full-color domain and scaled to a data size that is less than an initial data size for the image frame. The converted pixel data may be processed through one or more other pipelines stages and output for storage, further processing, or display. In some embodiments, a back-end interface may be implemented as part of the image signal processor via which image data collected from sources other than the image sensor may be received and processed through various pipeline stages at the image signal processor.

    Abstract translation: 图像处理流水线可以以多个速率处理图像数据。 从图像帧的图像传感器收集的原始像素数据流可以通过图像信号处理器的一个或多个流水线级进行处理。 然后可以将原始像素数据流转换为全色域并缩放为小于图像帧的初始数据大小的数据大小。 转换的像素数据可以通过一个或多个其他管道级进行处理,并输出用于存储,进一步处理或显示。 在一些实施例中,后端接口可以被实现为图像信号处理器的一部分,通过该图像信号处理器从除图像传感器之外的源收集的图像数据可以通过图像信号处理器处的各种流水线级被接收和处理。

    SYSTEMS AND METHODS FOR REDUCING FIXED PATTERN NOISE IN IMAGE DATA

    公开(公告)号:US20250097596A1

    公开(公告)日:2025-03-20

    申请号:US18970459

    申请日:2024-12-05

    Applicant: Apple Inc.

    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.

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