Stimulating Image Generation for Contrast Sensitivity Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for measuring contrast sensitivity are time-consuming and require repeated tests to achieve reliable results, as they depend on subjective human perception.
Innovation Solution
An image generation apparatus that produces a stimulating image with a luminance map and a contrast map, where the luminance changes with a specific spatial frequency and the contrast gradually decreases along an axis, allowing for efficient contrast sensitivity measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional repeated testing is performed to improve measurement reliability, then measurement reliability is improved, but measurement time increases
Solution Approach 1:
The patent divides the measurement process into two distinct phases: a training phase where multiple images are presented to establish baseline visibility, and a measurement phase where fewer images are needed for accurate contrast sensitivity determination. This segmentation allows the system to learn subject-specific visibility characteristics once, enabling faster subsequent measurements with higher reliability.
Solution Approach 2:
The patent performs preliminary training measurements before the actual contrast sensitivity measurement. During this training phase, the system presents multiple images at different contrast levels to establish the subject's visibility thresholds and reliability factors. This preliminary action creates a foundation that enables more accurate and faster subsequent measurements without requiring repeated full-length test sequences.
2Loss of time
If multiple images are presented simultaneously to reduce measurement time, then measurement time is reduced, but determination reliability decreases due to subjective perception
Solution Approach 1:
The patent implements a feedback mechanism where the system presents multiple images simultaneously at different contrast levels and spatial frequencies, then uses the subject's responses to calculate reliability factors. These reliability factors are fed back into the measurement algorithm to weight and adjust the final contrast sensitivity determination, compensating for subjective perception variability and improving determination reliability even with simultaneous image presentation.
3Measurement precision
If a large-scale examination apparatus is used to perform vision test, then measurement precision is improved, but device complexity and accessibility worsen
Solution Approach 1:
The patent creates a universal vision testing system that can be implemented on standard display devices (monitors, tablets, smartphones) without requiring specialized large-scale examination apparatus. The method uses software-based image generation and presentation that adapts to different display technologies, making high-precision contrast sensitivity measurement accessible in casual settings while maintaining measurement precision through standardized protocols and calibration procedures.
Data Source
AI summary
A contrast sensitivity measurement apparatus (1) generates a stimulating image to be output to an external display device (20) for measuring contrast sensitivity of a user. An image scale setting unit (12) determines the spatial frequency in units of pixels on the basis of an observation distance, physical characteristics of the external display device (20), and visual characteristics of a human. A carrier waveform generation unit (13) generates a luminance map in which a change of luminance along a first axis follows the spatial frequency. A contrast map generation unit (14) generates a contrast map in which contrast gradually decreases from one end to another end along a second axis, and an equal contrast line forms a given waveform. A stimulating image synthesis unit (15) generates the stimulating image by synthesizing the luminance map and the contrast map.