How to choose machine vision light source?

 In machine vision systems, the selection of machine vision light sources is very important. It can directly affect the quality of input data and application effects. In order to ensure good image quality and obvious features. The following Chengdu Xinxiwang Company introduces the basic elements of machine vision light source selection:

1. Contrast

Contrast is very important for machine vision. The important task of lighting in machine vision applications is to create the greatest contrast between the features that need to be observed and the image features that need to be ignored, so that the features can be easily distinguished. Contrast is defined as sufficient grayscale difference between a feature and its surrounding area. Good lighting should ensure that the features to be detected stand out from the rest of the background.

2. Robustness

Robustness means having a good adaptation to the environment. A good light source needs to have the same effect in practice as it does in the laboratory.

3.Brightness

When choosing between two light sources, the best choice is to choose the brighter one. When the light source is not bright enough, three bad situations may occur. First, the signal-to-noise ratio of the camera is not enough; because the brightness of the light source is not enough, the contrast of the image is bound to be insufficient, and the possibility of noise appearing in the image also increases. Secondly, the brightness of the light source is not enough, so the aperture must be increased, thereby reducing the depth of field. In addition, when the brightness of the light source is not enough, random light such as natural light will have a greater impact on the system. 

4. The light source is predictable

When a light source is incident on an object surface, the reflection of the light source is predictable. Light sources may be absorbed or reflected. The light may be completely absorbed (black metal material, the surface is difficult to illuminate) or partially absorbed (causing a change in color and brightness). Light that is not absorbed will be reflected, and the angle of the incident light is equal to the angle of the reflected light. This scientific law greatly simplifies the machine vision light source, because the ideal effect can be achieved by controlling the light source.

5. Uniformity

Uniformity is a very important technical parameter of the light source. The light source with good uniformity makes the system work stably.

6. Maintainability

Maintainability mainly refers to the ease of installation and replacement of light sources.

7. Lifespan and calorific value

The brightness of the light source is not easy to decay too quickly, which will affect the stability of the system and increase maintenance costs. The brightness of lamps with high calorific value decays quickly, and the life of the light source will also be greatly affected.