ColourWorker – Turn Your Phone Into a Scientific Sensor

Education

🌱 Student CREST Award

How does the light storage environment affect the appearence of Parsley plants?

Plants growing under different lighting conditions

1: Experiment Design

Parsley plants stored under different lighting conditions for 2 weeks.

2: Data Collection

Plant images acquired daily.

3: Data Export

Image data exported to Google Sheets for analysis.

4: Analyze

Leaf colour change over time under different lighting conditions

Research

🌱 Performance Evaluation

Comparing image-based estimates of leaf SPAD-value and chlorophyll concentration made using PhotoFolia with Minolta 502 SPAD meter and laboratory assay.

Rice varieties under different growth conditions

1: Plant Protocol

Four different varieties of rice grown at Mahidol University under control and Nitrogen deficient conditions.

2: Three different measurement types

(1) PhotoFolia (2) Minolta 502 SPAD meter (3) spectroradiometric chlorophyll assay following acetone extraction

3: SPAD value

PhotoFolia achieves a Mean Absolute Percentage Error (MAPE) of 4.11% compared to the Minolta 502 SPAD meter.

4: Chlorophyll Concentration

PhotoFolia achieves a Mean Absolute Percentage Error (MAPE) of 7.23% compared to the laboratory assay (acetone extraction).

Research

🌡️✋ Pilot Study

Tracking subtle skin colour dynamics in response to thermal stress.

1: Experimental Protocol

Test subject immersed their hand in thermally contrasting water baths, hot (~43°C) or cold (~0°C) for 5 minutes to trigger distinct vascular responses.

2: Temporal Imaging

We captured a record of skin colour change over 60 minutes.

3: Calibrated Colour Imagery

Although perceptually subtle to the naked eye, barely distinguishable between baseline (0 min) and the first post‑immersion frame (5 min) these images encode physiologically significant shifts in skin tone

4: Quantifying the Imperceptible

Time series of median L*a*b* values extracted from each image reveal that ColourWorker can detect vascular responses invisible to casual observation.

5: Divergent Pathways

Plotting colour evolution within L*a*b* space suggest an interesting asymmetry: cold immersion produces a hysteresis loop, where the outbound (cooling) and return (rewarming) trajectories trace distinct paths. This suggests separate physiological mechanisms govern vasodilation during rewarming versus the initial vasoconstrictive response.

Education

👩‍🍳 Student Project

How does sugar content affect browning of cookies?

1: Experient Design

Simple sugar cookies were made with different amounts of sugar and baked for 10, 12 and 14 mins.

2: Data collection

Biscuit images are obtained for different conditions.

3: Results

Average biscuit L*, a*, b* values obtained from ColourWorker web app.

4: Conclusion

Bake time drives a generalized browning that increases both redness (a*) and yellowness (b*) reflecting overall progression of Maillard and caramelization reactions. Increase in sugar concentration shifts the hue of browning, enhancing redness (a* ↑) while reducing yellowness (b* ↓). This is likely due to changes in caramelization chemistry and suppressed Maillard pathways at high sugar levels.