Compensation for black level changes

A method comprising:

• receiving one or more frames of image data at an image signal processing pipeline, the image signal processing pipeline configured to apply black level compensation to the one or more frames of image data;
• copying at least one frame of the one or more frames of image data into a buffer prior to application of black level compensation to the at least one frame by the image signal processing pipeline;
• estimating black level shift in the at least one frame copied into the buffer;
• determining black level shift in each of the one or more frames based on the estimated black level shift in the at least one frame;
• and
• applying black level compensation to the one or more frames via the image signal processing pipeline based on the determined black level shift in each of the one or more frames.

A system comprising:

• an image sensor configured to capture raw image data, the image sensor including a pixel array having a plurality of imaging pixels configured to receive light and a plurality of dark pixels configured to generate a hardware black level reference for the raw image data;
• a hardware image signal processing pipeline configured to receive the raw image data from the image sensor and to apply black level compensation to the received raw image data;
• a processor;
• and
• a memory having image analysis software encoded therein, the image analysis software executable by the processor to determine a software black level reference for the raw image data;
• wherein the system is configured to provide at least one frame of the raw image data before black level compensation of the at least one frame by the hardware image signal processing pipeline, to analyze the at least one frame of the raw image data via the processor and the image analysis software, and to modify at least one parameter of the black level compensation of the hardware image signal processing pipeline based on the software black level reference determined through the analysis of the at least one frame of the raw image data.