Basler raL2048-48gm Manuel d'utilisateur télécharger pdf (Page 189)

AW00118302000 Standard Features

Basler racer GigE 179

10.8 Shading Correction

Two types of shading correction are available on the camera, offset shading correction and gain

shading correction. You can set the camera to only perform offset shading correction, to only

perform gain shading correction, or to perform both types of shading correction.

10.8.1 Offset Shading Correction

When a line scan camera with a digital sensor captures a line in complete darkness, all of the pixel

values in the line should be near zero and they should be equal. In practice, slight variations in the

performance of the pixels in the sensor will cause some variation in the pixel values output from the

camera when the camera is capturing lines in darkness. Offset shading correction (also known as

dark signal non-uniformity (DSNU) correction) corrects for this type of variation.

Offset shading correction works by adding an individual gray value to each pixel value in the

acquired lines. The gray values used for correction are included in a "shading file", commonly also

referred to as a "shading set". In order to use offset shading correction, the user must enable offset

shading correction and activate the related defaultshading file or the previously created

usershading file (see below).

10.8.2 Gain Shading Correction

When a line scan camera with a digital sensor captures a line with the camera viewing a uniform

light-colored target in bright light, all of the pixel values in the line should be near their maximum

gray value and they should be equal. In practice, slight variations in the performance of the pixels

in the sensor, variations in the optics, and variations in the lighting will cause some variation in the

pixel values output from the camera. Gain shading correction (also known as photo response non-

uniformity (PRNU) correction) corrects for this type of variation.

Gain shading correction works by applying an individual multiplier to each pixel value in the

acquired lines. The multipliers used for correction are included in a "shading file", commonly also

referred to as a "shading set". In order to use gain shading correction, the user must enable gain

shading correction and activate the related defaultshading file or the previously created

usershading file (see below).

1 2 ... 184 185 186 187 188 189 190 191 192 193 194 ... 237 238

Pas de commentaire

Basler raL2048-48gm Manuel d'utilisateur Page 189