Residual Phase Difference Processing for Dual PDAF Sensor Data Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dual PDAF camera sensors generate extensive data streams that are power and memory intensive, requiring significant processing resources for phase difference pixel data, which is only necessary when scene changes occur, leading to inefficiencies in data transfer and processing.
Innovation Solution
Calculating and transmitting residual phase difference values between frames, which indicate changes in the region-of-interest, using compression techniques like run-length encoding to reduce data volume, and reconstructing phase difference pixel data in the camera processor for autofocus processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all phase difference pixel data from dual PDAF sensor is transmitted to camera processor, then complete autofocus processing can be performed, but data transfer volume and processing requirements increase significantly
Solution Approach 1:
The patent extracts and transmits only the essential autofocus information (phase difference values and region-of-interest data) from the dual PDAF sensor to the camera processor, rather than transmitting all raw pixel data. This selective extraction reduces data transfer volume while maintaining sufficient information for reliable autofocus processing.
Solution Approach 2:
The patent applies local quality by identifying and prioritizing processing of region-of-interest areas where phase changes occur. Instead of uniformly processing all sensor data, the system focuses computational resources on specific regions that contain meaningful autofocus information, reducing overall processing requirements.
2Productivity
If residual phase difference values are calculated and transmitted instead of complete phase difference pixel data, then data transfer efficiency improves, but processing complexity at the sensor increases
Solution Approach 1:
The patent applies preliminary action by performing residual phase difference calculation and region-of-interest identification at the sensor level before data transmission. This preprocessing reduces the data burden on the camera processor and improves overall system productivity, as only essential changes are transmitted for final autofocus determination.
3Use of energy by moving object
If compression techniques are applied to residual phase difference values, then memory and power requirements are reduced, but processing time for compression and decompression is added
Solution Approach 1:
The patent applies parameter changes by implementing compression techniques that modify the representation of phase difference data. By changing the data format and utilizing run-length encoding or similar compression methods, the system reduces memory and power requirements while maintaining the essential autofocus information needed for accurate focus determination.
Data Source
AI summary
A method of image processing includes capturing two frames of image data using a camera having a phase detection auto focus (PDAF) sensor, subtracting phase difference pixel data associated with the two frames of image data to produce residual phase difference values, detecting a region-of-interest change based on the residual phase differences values, and determining a focus for the PDAF camera sensor based on the detected region-of-interest change. The method may further include compressing the residual phase difference values, sending the compressed residual phase difference values to a processor, and reconstructing, with the processor, the phase difference pixel data from the compressed residual phase difference values.