Machine vision systems often require bright and homogeneous illumination, so features of interest are easier to process. LEDs are often used for this purpose, and this is likely to remain one of their major uses until the price drops low enough to make signaling and illumination uses more widespread. Barcode scanners are the most common example of machine vision, and many low cost products use red LEDs instead of lasers. Optical computer mice are an example of LEDs in machine vision, as it is used to provide an even light source on the surface for the miniature camera within the mouse. LEDs constitute a nearly ideal light source for machine vision systems for several reasons:
LEDs are often used for what type of systems?
Machine vision

The emergence of Susa as a city, as determined by radiocarbon dating, dates back to early 4,395 BC. There are dozens of prehistoric sites across the Iranian plateau, pointing to the existence of ancient cultures and urban settlements in the 4th millennium BC. During the Bronze Age, Iran was home to several civilizations including Elam, Jiroft, and Zayande River. Elam, the most prominent of these civilizations, developed in the southwest of Iran, alongside those in Mesopotamia. The emergence of writing in Elam was paralleled to Sumer, and the Elamite cuneiform was developed since the 3rd millennium BC.
What ancient city dates back as early as 4395 BC in Iran?
Susa

Evidence of wheeled vehicles appeared in the mid 4th millennium BC, near-simultaneously in Mesopotamia, the Northern Caucasus (Maykop culture) and Central Europe. The wheel initially took the form of the potter's wheel. The new concept quickly led to wheeled vehicles and mill wheels. The Sumerians' cuneiform writing system is the oldest (or second oldest after the Egyptian hieroglyphs) which has been deciphered (the status of even older inscriptions such as the Jiahu symbols and Tartaria tablets is controversial). The Sumerians were among the first astronomers, mapping the stars into sets of constellations, many of which survived in the zodiac and were also recognized by the ancient Greeks. They were also aware of the five planets that are easily visible to the naked eye.
What did the Sumerians map stars into?
sets of constellations