Vision Systems

Vision is the ability to see and recognize objects by collecting the light reflected of these objects into an image and processing that image. Robot vision makes use of computers or other electronic hardware to analyze visual images and recognize objects of importance in the current application of the robot.

An electronic image is an array of pixels that has been digitized into the memory of a computer. A binary number is stored in each pixel to represent the intensity and possibly the wavelength of the light falling on the part of the image.

Manufacturing Tasks
Selecting parts that are randomly oriented from a conveyor. Parts identification. Limited inspection. Visual servoing & Navigation.

Classification of Vision Systems
Two-dimensional, or three-dimensional model of the scene. According to the number of gray levells:
 Binary image (Black and white).
 Gray image.
 Color Image (RGB image).

Components of Vision Systems
The camera, and digitizing hardware,
A digital computer, Hardware and software necessary to interface them.

Image Processing

Image processing relates to the preparation of an image for later
analysis and use. Image processing is the collection of routines & techniques that improve, simplify, enhance, or otherwise alter an image.

Image Analysis
Image analysis ids the collection of processes in which a captured
image that is prepared by image processing is analyzed in order to
extract information about the image and to identify objects or facts about the object or its environment.
Histogram Of Images
A histogram is a representation of the total number of pixels of an image at each gray level. Histogram information can help in determining a cutoff point when an image is to be transformed into binary values.

Thresholding is the process of dividing an image into different levels by picking a certain grayness level as a threshold, comparing each pixel value with the threshold, and then assigning the pixel to the different levels, depending on whether the pixel’s grayness level is below or above the threshold level.

Connectivity Paths
Connectivity establishes whether neighbouring pixels have the same properties, such as being of the same region, coming from the same object, having a similar texture.

Three fundamental connectivity paths for two-dimensional image processing & analysis:
 +4 or x4 connectivity
 H6 or V6 connectivity
 8 connectivity

Filtering Techniques
Frequency-related techniques operate on the Fourier Transform of the signal, Spatial-domain techniques operate on the image at the pixel