The adopted answer has a small error, I here to correct and improve:
1, first of all, what is machine vision? Summarized in an easy-to-understand words is: machine vision is to replace the human eye with a machine to make a variety of measurements and judgments.
2, a typical machine vision system includes: light source, lenses, industrial cameras (including CCD cameras and COMS cameras), image processing unit (or image capture card), image processing software, monitors, communication / input and output units. (The term CCD camera is very unprofessional, machine vision systems generally use industrial cameras, one of the differences between industrial cameras is the use of different image sensors, the more common is the CCD image sensor and CMOS image sensor.)
Or: the entire machine vision system is mainly composed of two major parts of the image acquisition and image processing, image acquisition part of the main light source, lenses, industrial cameras and image acquisition card, image processing part of the image processing software is composed of.
3, light source: (light can be divided into visible and invisible light, which directly affects the quality of the input data and the application of the effect)
Lighting system can be divided into according to the method of illumination: backward illumination, forward illumination, structured light and stroboscopic illumination.
Backward illumination is the subject placed between the light source and the camera, which has the advantage of obtaining high-contrast images.
Forward illumination is the light source and the camera are located on the same side of the subject, this way is easy to install.
Structured light illumination is to project a grating or a line light source, etc. onto the DUT, and demodulate the three-dimensional information of the DUT according to the aberrations they produce.
Frequency flash illumination is a high-frequency light pulse irradiated onto the object, and camera shooting requires synchronization with the light source.
4, the lens selection should pay attention to: ① focal length ② target height ③ image height ④ magnification ⑤ image to the target distance ⑥ center / node ⑦ aberration
5, industrial camera: choose the right industrial camera is the whole machine vision system is very important step
Common classifications: according to the color of the imaging, can be divided into color cameras and black and white cameras; according to the resolution, the number of pixels in 380,000 pixels. resolution, the number of pixels below 380,000 for the ordinary type, the number of pixels in more than 380,000 high-resolution type; according to the size of the photosensitive surface size division, can be divided into 1/4, 1/3, 1/2, 1-inch camera; according to the scanning mode division, can be divided into line scanning camera (line camera) and surface scanning camera (surface array camera) two ways; (surface scanning camera can be divided into interlaced camera and progressive scanning camera); according to the synchronization mode division, can be divided into line scanning camera and progressive scanning camera; according to the synchronization mode division, can be divided into line scanning camera and progressive scanning camera. (The surface scanning camera can be divided into interlace scanning camera and progressive scanning camera); according to the division of synchronization, can be divided into ordinary camera (internal synchronization) and with external synchronization function of the camera and so on.
Common brands: Germany Optronis, Switzerland PhotonFocus, the United States ISG, Germany Smartek, etc.
6, image acquisition card: image acquisition card is mainly composed of video input, A/D conversion, timing and acquisition control, image processing, bus interface and control, output and control of several major modules. According to the different types of industrial cameras in the machine vision system, the choice of image acquisition card should also be different. For example, if the camera is black and white, you can choose black and white image acquisition card, of course, because the color image acquisition card can also collect the same gray level black and white images, therefore, you can also choose color image acquisition card. However, if the camera is color, you can only choose color image acquisition card; in addition, if the camera is an analog camera, the image acquisition card used is also the corresponding analog image acquisition card. The image acquisition card used in conjunction with the digital camera should be a digital image acquisition card; also, the line scan image acquisition card supports both line scanning cameras, but also supports the surface scanning cameras. Face-scanning image acquisition cards generally only support face-scanning cameras, but not line-scanning cameras. There are other considerations.
7, machine vision system practical applications:
Military: aviation landing position, takeoff status; ballistic/rocket ejection, bullet discharging, and so on.
Scientific research: crystallization; PIV fluid, particle research; combustion, coating process measurement.
Production: product sputtering, encapsulation, rolling, mining; machinery operation action analysis or fault diagnosis.
Biology: kinesiology, biomechanics; biological movement analysis: human body, animal movement analysis; rehabilitation physiotherapy, etc.
Medical: medical instruments, cells, valves movement; bleeding observation; swallowing, respiratory flagellum movement, etc..
There are also other fields that can be applied in sports, exercise, automobile, etc.