In-Sensor Face Detection Using Vertical Stripe Scanning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Modern cameras require large and area-consuming framestores to capture and analyze scenes, leading to substantial processing time and power consumption for identifying regions of interest, such as faces, due to the need to store and process entire frames.

Innovation Solution

Implementing an image sensor with a detector that scans the scene in successive time intervals using vertical stripes, storing only a portion of the scene in a smaller image buffer, and using a rolling buffer for face detection, allowing for efficient detection and processing of faces without needing to store the entire frame.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large framestore is used to store the entire scene, then complete scene data is available for analysis, but the device area and memory size increase substantially

Engineering Contradiction:
Improvescene data completenessVSAvoidframestore size
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent extracts only the essential information needed for object detection (face presence indicators) from the complete scene data, storing merely the presence/absence flags in a compact buffer rather than the entire frame data. This extraction principle reduces the stored data from full-frame resolution to minimal detection markers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of storing the actual scene data, the system creates simplified copies in the form of presence/absence indicator buffers that represent the essential detection information without duplicating the full scene data, thereby reducing memory requirements while preserving detection capability.

Inventive Principle:
Principle #26Copying

2Measurement precision

If the entire frame is stored and analyzed by a high-power processor, then accurate object identification is achieved, but processing time and power consumption increase

Engineering Contradiction:
Improveobject identification accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary scanning of the scene during the imaging process itself, using the imaging sensor to detect face presence indicators before full frame processing is required. This preliminary detection action occurs concurrently with scene capture, eliminating the need for subsequent full-frame analysis.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements continuous face detection scanning throughout the scene capture process, maintaining detection operations continuously rather than performing batch processing after frame capture. This continuous action allows detection to proceed in parallel with imaging, maximizing utilization of the imaging process for dual purposes.

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If the entire frame is stored and analyzed by a high-power processor, then accurate object identification is achieved, but power consumption increases

Engineering Contradiction:
Improveobject identification accuracyVSAvoidprocessor power consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by stationary object

Solution Approach 1:

The system extracts only the minimal necessary data (face presence indicators) from the complete scene, avoiding the energy-intensive operation of processing full-frame data. This extraction reduces computational load and associated power consumption while maintaining detection accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates simplified indicator copies instead of processing full-frame data, using low-power buffer operations to store and retrieve presence/absence flags rather than performing high-power processor operations on complete image data, thereby significantly reducing energy consumption.

Inventive Principle:
Principle #26Copying

4Area of stationary object

If a smaller image buffer is used to store only a portion of the scene, then device area is reduced, but complete scene coverage requires multiple scans

Engineering Contradiction:
Improveimage buffer sizeVSAvoidscene scanning efficiency
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The system employs periodic scanning of the scene in successive time intervals, systematically working through different portions of the scene across multiple scan cycles. This periodic scanning approach ensures complete scene coverage is achieved over time while using minimal buffer memory at any given moment.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent introduces the time dimension to the scanning process, transforming a spatial storage problem into a temporal processing solution. By scanning different scene portions across successive time intervals rather than loading the entire scene simultaneously, the system achieves complete coverage with minimal buffer requirements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS8345125B2Object detection using an in-sensor detector
Publication Date: 2013.01.01 SEMICON COMPONENTS IND LLC
  • US8345125B2 patent drawing
  • US8345125B2 patent drawing
  • US8345125B2 patent drawing

AI summary

Systems and methods are provided for detecting an object of object class, such as faces, in an image sensor. In some embodiments, the image sensor can provide a scan sequence that scans a scene over multiple time intervals. The image sensor can scan, in succession, portions of a scene, where each of the portions covers a different amount or location of the scene. This way, the scanned portions can be saved in an image buffer that is sized significantly smaller than an entire frame. In some embodiments, when the image sensor detects the presence of an object of the object class, the image sensor can store positional information (e.g., location and size of the object) in a region of interest buffer. The image sensor can output the positional information to aid an electronic device, such as a camera, perform various functions, such as automatic exposure and color balancing.