Line Capture Modes
Three fundamental line capture modes are applicable to the line-scan camera and grabber association:
LineCaptureMode |
Description |
ALL |
Take All Lines – Each delivered camera line results into a line acquisition. If the downweb motion speed is varying, the line-scanning process of the camera should be rate-controlled accordingly. |
PICK |
Pick A Line – The line-scanning process of the camera is running at a constant rate. Each pulse occurring at the Downweb Line Rate determines the acquisition of the next line delivered by the camera. |
ADR |
Advanced Downweb Resampling – The line-scanning process of the camera is running at a constant rate. Each pulse occurring at the Downweb Line Rate determines the computation of a line from a set of presently recorded lines delivered by the camera. |
When LineCaptureMode = ALL, the Downweb Line Rate and the Camera Line Rate are the same. The requested resolution and the effective motion speed univocally dictate the Downweb Line Rate. Then the camera has to be chosen to operate at an exactly matching Camera Line Rate, even if the speed of motion is varying. This imposes a requirement for a rate-controllable camera.
Using Downweb Resampling offers a way to eliminate the requirement for this exact match. The Camera Line Rate may be chosen at a fixed value, and the acquisition will still acquire lines at the expected downweb resolution, even when the speed of motion is varying.
The ADR – Advanced Downweb Resampling – technology re-samples the camera data along the vertical direction using multi-tap interpolation filter while the Pick-A-Line technology uses a rough resampling method, namely the Nearest neighbor method. (The ADR technology is exclusively available on Grablink Avenue and Grablink Express.)
For technical information, refer to the LineCaptureMode reference.
Synchronization modes, in function of the camera operation mode
Camera operation class |
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ALL |
PICK |
ADR |
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CAMERA |
PERIOD |
PULSE |
CONVERT |
EXPOSE |
PERIOD |
PULSE |
CONVERT |
PERIOD |
CONVERT |
||
LINE |
LxxxxSP |
✓ |
|
|
|
|
✓ |
✓ |
✓ |
✓ |
✓ |
LxxxxRP |
|
|
✓ (*) |
✓ (*) |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
|
LxxxxSC |
✓ |
|
|
|
|
✓ |
✓ |
✓ |
✓ |
✓ |
|
LxxxxRC |
|
✓ |
✓ |
✓ |
|
|
|
|
|
|
|
LxxxxRG |
|
✓ |
✓ |
✓ |
|
|
|
|
|
|
|
LxxxxRG2 |
|
✓ |
✓ |
✓ |
|
|
|
|
|
|
|
TDI |
LxxxxSP |
✓ |
|
|
|
|
✓ |
✓ |
✓ |
✓ |
✓ |
LxxxxRP |
|
|
✓ (*) |
✓ (*) |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
|
(*) These settings are not recommended since the camera sensitivity is varying with the line rate.