Transcript Machine Vision

Machine Vision
Image Acquisition
> Resolution
Ability of a scanning system to
distinguish between 2 closely
separated points.
> Contrast
Ability to detect shades of difference
from pixel to pixel.
The lowest quality machine vision system uses a simple two-state
sensor that registers each pixel as being either black or white.
Image Analysis Techniques
> Windowing
Concentrating vision system analysis on a small
field of view to conserve computer resources of
run time & storage.
> Thresholding
Reducing an image to binary black or white
pixels.
> Histogramming
A frequency histogram is constructed for the
pixel counts at each level of gray
accommodated
Edge Detection
> Binary Logic Search
Guide a search through an image, one pixel at
a time, as the search finds an edge, it will
follow it completely around the object.
> Local Edge Elements
Roberts Cross-Operator
Template & Filters
Roberts Cross-Operator
Computes the square root of the
sum of the squares of the adjacent
diagonal differences between pixel
gray-scale values.
Filter
Small template for finding a
“Vertical” edge.
-1 0 1
-1 0 1
-1 0 1
Find the sum of products of each
point in the image matrix with all
points in the filter matrix.