Resolution Enhancement
Algorithmic interpolation of image intensity data allows an optical inspection system to locate the boundary of an object with a precision finer than the spacing of the physical camera sensor pixels. This digital processing method, known as sub pixel edge detection, enables automated optical inspection machines to measure fine pitch electronic components and solder joints without needing high magnification lenses that would reduce the field of view. It mathematically improves the measurement resolution of the inspection hardware.
Algorithmic Execution
The processing software analyzes the gray level gradients across multiple adjacent pixels to fit a continuous curve that represents the true transition of the edge. Rather than treating pixel boundaries as hard limits, the sub pixel edge detection algorithm calculates the peak of the derivative of the image brightness to find the exact edge center. This calculation allows the system to achieve measurement resolutions down to a fraction of a micron.
Because the process is computationally efficient, it can be run in real time on high speed production lines.
Inspection Benefit
This high precision inspection minimizes false calls and escapes on high density circuit board assemblies. It ensures that the measurement of tiny features remains repeatable even under varying lighting conditions. This technique keeps the production process running smoothly.
It supports the assembly of sub-millimeter components.
