polarization camera

1、 Use DoLP range slider to detect hidden scratches in transparent materials

Polarization can be used to detect internal stress and scratches in transparent materials such as plastic or glass. In this example, we will see LUCID'spolarization cameraHow to measure the degree of linear polarization (DOLP) with the arena software development kit. By using ArenaView GUI to display DoLP images, we can detect stresses and defects in transparent materials that are not detected by conventional visible light cameras.

2、 Testingtransparent materialrequirement

·Triton (TRI050S-P) or Phoenix (PHX050S-P) 5.0MP monopolarization camera(Color support is about to be released)

·Triton5.0MP polarization firmware version: 1.32.0.0 or higher

·Phoenix 5.0MP polarization firmware version: 1.40.0.0 or higher · ArenaSDK-Win32/64 bit version: 1.0.12.12 or higher.

3、 Testing methods for transparent materials

The technique of using polarized light sources to irradiate light through transparent objects is effective in detecting internal stress, internal debris, and surface scratches when detecting transparent materials or solutions. The angle of a polarized light source will change as it passes through an object. Any changes in AoLP will be measured and displayed in ArenaView. ArenaView has a built-in DoLP display that maps a range of RGB colors to different polarization angles.

4、 Introduction to Detecting Phone Case Examples

When inspecting defects on transparent materials such as phone cases made of transparent plastic, it may be difficult to identify certain defects using a standard monochrome camera. When using images, the DoLP information in the image can be used to identify and enhance these defects.

What is' Degree of Linear Polarization '(DoLP)?

DoLP is a measurement value that represents the actual amount of light polarized to a specific angle. The proportion range of DoLP is from 0 to 1. Linearly polarized light will have a DoLP of 1. Non polarized light (such as sunlight) will have a DoLP of 0.

Step 1

Set the camera pixel format to 'DoLP Mono8'. Set the camera pixel format to 'Polarized DoLP_Sono8' to enable camera processing and output of DoLP information.

Step 2

Enable the 'Range selector' display format. Place the plastic phone case on top of the polarized backlight. In the DoLP view, defects such as scratches become more prominent. However, smaller defects are still difficult to distinguish from small particles and dust. This can be solved by changing the color representation of the data and improving contrast. Select the 'Range Selectors' display format in the' Range Selectors' panel to adjust the degree range and external color.

Step 3

Set the minimum and maximum AoLP ranges to provide optimal contrast. Under Pixel Format Control, you can change the AoLP range to limit the display to only show a specific angle range. In this example, the display range has been set to 135 ° to 175 °. In other words, the entire color spectrum range will now be mapped to 135 ° to 175 ° instead of 0 ° to 180 °. This provides more color granularity and allows for better visualization of changes within a specified angle range. Any angle outside of 135 ° to 175 ° will be displayed in black.

The DoLP view can not only display defects that are difficult for standard cameras to see, but also enhance the contrast of smaller defects and improve defect recognition rates.