Devices and methods for obtaining high-local-contrast image data

摘要

Devices and methods for obtaining image data that preserves highlight details and shadow details from image data from a high dynamic range (HDR) image sensor are provided. For example, an image signal processor may include a first data path of a relatively high bit depth, front-end image processing logic, and a second data path of a relatively low bit depth. The first data path may receive HDR image data from an image sensor. The front-end image processing logic may convert the HDR image data into lower-bit-depth image data, while preserving highlight details and/or shadow details of the HDR image, by using at least two transfer functions that preserve different subsets of the high dynamic range. The second data path may output this lower-bit-depth image data to other image processing logic for additional image processing.

主权项

1. An image signal processor comprising:
first data path circuitry of a first bit depth configured to receive first image data of the first bit depth captured by an image sensor; front-end image processing logic circuitry configured to convert the first image data into second image data of a second bit depth, wherein the second bit depth is lower than the first bit depth, while preserving highlight details of the first image data or shadow details of the first image data, or both, by respectively applying at least two transfer functions to at least two copies of the first image data and mixing results of the applying; and second data path circuitry of the second bit depth configured to output the second image data to other image processing logic circuitry of the image signal processor, wherein at least a portion of the other image processing logic circuitry is configured to determine a brightness mask for use when mixing the results, the brightness mask based at least partly on a derived luminance density estimate of a next frame of the second image data using a previous frame of the second image data.