A novel systems solution for accurate colorimetric measurement through smartphone-based augmented reality

Area of Science:

• Color science and digital imaging
• Computer vision and augmented reality
• Applied metrology

Background:

• Accurate color quantification is vital for medical, agricultural, and food safety applications.
• Traditional laboratory color matching is laborious; digital imaging offers a portable alternative but faces challenges from non-linear image formation and variable lighting.
• Existing digital color correction methods often use discrete references, leading to potential bias due to limited observation.

Purpose of the Study:

• To develop a smartphone-based system for accurate and absolute colorimetric measurements.
• To address errors in digital color measurement caused by lighting and image formation.
• To provide a portable, user-friendly solution for precise color quantification.

Main Methods:

• A novel smartphone application integrating a custom color reference board with continuous color sampling.
• A color correction algorithm employing a first-order spatial varying regression model for enhanced accuracy.
• An augmented reality (AR) scheme with marker tracking to guide users in capturing images, minimizing non-Lambertian reflectance effects.

Main Results:

• The proposed system achieves device-independent colorimetric measurements, reducing color variance by up to 90% under varying lighting conditions.
• Experimental results demonstrate a 200% improvement in pH value reading accuracy compared to human interpretation.
• The integrated system, including the reference board, algorithm, and AR guidance, offers a novel solution for precise color measurement.

Conclusions:

• The developed smartphone-based system provides an accurate and absolute method for colorimetric measurement, overcoming limitations of traditional and existing digital techniques.
• The combination of a continuous color reference board, advanced correction algorithm, and AR guidance offers a robust solution for diverse applications.
• This technique shows significant potential for improving color reading accuracy in various fields, including medical diagnostics, agriculture, and food safety, as evidenced by pH test reading applications.