The calculation of linear dimension and image area using a digitising tablet and personal computer

Area of Science:

• Biomedical Engineering
• Medical Imaging Analysis
• Image Processing

Background:

• Accurate measurement of biological structures is crucial in research.
• Existing methods can be expensive or complex.
• A need exists for cost-effective and reliable image analysis tools.

Purpose of the Study:

• To evaluate the accuracy and reproducibility of a new, inexpensive image analysis system.
• To determine the system's performance across different shape sizes and symmetries.
• To assess factors influencing measurement accuracy, such as operator skill.

Main Methods:

• Development of a low-cost system using a personal computer and digital graphics tablet.
• Systematic testing of area and perimeter measurement efficacy.
• Analysis of accuracy and reproducibility based on cross-sectional area size and shape.
• Comparison of measurements with known values and assessment of variability.

Main Results:

• The system demonstrated high accuracy and reproducibility, particularly for larger cross-sectional areas.
• Measurements were generally underestimated by less than 2%, with variability typically below 2%.
• Accuracy and reproducibility decreased for smaller shapes and those with rectangular symmetry.

Conclusions:

• The described system offers a cost-effective solution for image-area and perimeter measurement.
• Its efficacy is validated, with performance scaling positively with object size.
• The system is reliable for various applications, though caution is advised for small or rectangular shapes.