Finger Detection Using Differential Imaging and Adaptive Windows
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing finger detection systems face instability and reduced accuracy when a finger is not fully contacted or when different control functions require different image features, necessitating time division methods that decrease system response time.
Innovation Solution
A finger detection device that dynamically determines windows of interest in a single image frame, using a light source, sensor, and processor to identify a finger region and generate differential images, allowing adaptation to various control functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If time division method is used to capture different image frames for different control functions, then adaptability to different control functions is improved, but system response time increases
Solution Approach 1:
The patent divides the image frame into multiple windows of interest (WOIs) corresponding to different control functions. Each WOI can be independently processed for different functions (e.g., fingerprint detection, PPG detection, navigation) using the same captured image frame, eliminating the need for time division while maintaining functional adaptability
Solution Approach 2:
The patent enables a single image frame to serve multiple control functions by identifying different windows of interest within the same frame. The processor determines WOIs that can be adapted for various functions such as fingerprint detection, PPG detection, and navigation, making the image frame universal for different control purposes
2Measurement precision
If different image frames are captured using different image capturing parameters, then image processing accuracy for different control functions is improved, but device complexity increases
Solution Approach 1:
The patent segments the image frame into multiple windows of interest, allowing different regions to be processed for different control functions using the same capturing parameters. This eliminates the need to manage multiple sets of capturing parameters while maintaining processing accuracy through spatial segmentation
Solution Approach 2:
The patent dynamically determines windows of interest based on the captured image frame and identifies finger regions adaptively. The processor dynamically selects and processes different WOIs for different control functions, providing flexibility without requiring multiple fixed capturing parameter sets
3Ease of operation
If finger detection is performed with finger not fully contacting sensing surface, then ease of operation is improved, but detection accuracy deteriorates
Solution Approach 1:
The patent segments the image frame into multiple windows of interest and identifies finger regions within these segments. This allows the system to detect finger presence and characteristics even when only part of the finger contacts the sensing surface, as each WOI can independently identify finger features
Solution Approach 2:
The patent enables detection functions to operate with partial finger contact by processing different windows of interest that may contain partial finger regions. The system can identify finger characteristics from incomplete contact areas, allowing ease of operation without requiring full finger contact for accurate detection
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Improves response time by enabling the same image frame to be used for multiple control functions with high accuracy by identifying and isolating relevant image regions.
Implementation Method 1
The light source is configured to emit light toward a sensing surface of the finger detection device
Implementation Method 2
The light sensor is configured to acquire a first image frame and a second image frame toward the sensing surface
Implementation Method 3
The processor is configured to calculate a difference of the first image frame and the second image frame to generate a differential image frame, identify a finger region in the differential image frame
Data Source
AI summary
There is provided a finger detection device including a light source, a light sensor and a processor. The light sensor respectively captures a first image frame and a second image frame corresponding to turning on and turning off the light source. The processor calculates a differential image frame of the first image frame and the second image frame, determines a covered region in the differential image frame and identifies whether the covered region is a finger region or not. If the covered region is not the finger region, the processor controls the light sensor to acquire new image frames. If the covered region is the finger region, the processor determines different windows of interest in the finger region.