Resolution Constant
Center to center distance between adjacent pixels on an image sensor determines the maximum spatial detail a camera can capture. The pixel pitch is measured in micrometers and influences both the sensitivity and the clarity of the inspection system. Larger pixels generally collect more light but provide lower resolution for a given sensor size.
Fabric inspection cameras must balance these two factors to detect tiny yarn defects at high mill speeds.
Image Sharpness
Smaller values allow the system to resolve finer details such as individual hairiness or small nep structures. When the pixel pitch is too large relative to the defect size, the image appears blurred and the contrast is reduced. This makes it difficult for the detection algorithms to distinguish between a real fault and a minor texture variation.
Optimal performance occurs when the defect covers at least two or three pixels on the sensor.
Hardware Capability
Sensor design involves a trade off between pixel pitch and the total area of the imaging chip. A smaller pitch requires higher quality lenses to maintain focus across the entire sensor. In textile applications, the choice of camera is often driven by the width of the fabric and the smallest contaminant that must be detected.
High resolution systems often use line scan cameras with a very small pitch to cover wide fabric rolls.
Defect Identification
Accuracy in measuring the size of a foreign object depends on the known distance between pixels. Software uses the pixel pitch to convert digital measurements into real world units like millimeters or microns. This data is then used to grade the yarn or fabric according to international quality standards.
