Shad-o-Scan 3001/4501 User Manual (Draft)
41
Teledyne DALSA
with appropriate Resolution/Full Well mode. Press the
Browse…
button to select a defect
map file on the host and press
Upload (to Camera)
to start the transfer to the detector. The
upload will be confirmed with the message:
File Upload Completed
.
When attempting to upload a new defect pixel map, the detector will check the file
header. In case the header is incorrect, uploading the file will be blocked with error
message
The selected file write access to the device failed!
.
Delete
To delete a customer defect map file from the host, the
Factory/Custom Upload
selector in
the
File Access Control
menu has to be set to
Customer
before opening the
File Access
Control
menu through
Upload/Download File
.
Select Type Miscellaneous in the first drop list and in the second drop list defect map.
Ensure yourself before pressing the
Delete
button, the selected file will be deleted
immediately with the message:
File Deleted Successfully.
Downloading
Both customer and factory Defect Maps can be downloaded. Set the
Factory/Custom
Upload
selector in the
File Access Control
menu in the preferred position before opening
the
File Access Control
menu through
Upload/Download File
.
To transfer a defect map file from the detector to the host press the button:
Download (from
Camera)
. A browse screen will be opened to select the
Save as…
location on the host.
Pressing the
Save
button after selecting the correct name and location, the detector will
start a transfer of the defect map file of the selected Resolution/Full Well mode to the
host. The download will finish with
The file download completed successfully
message.
Dark/Gain Maps
Introduction
Dark and Gain reference maps are stored in detector non-volatile memory. These maps
contain information required for Flat Field Correction (FFC).
The Dark reference map is created without exposure to X-ray. The Gain reference map is
calculated from dark-corrected images without object in the X-ray field.
Separate Dark and Gain maps are available for different Readout- and Full Well modes.
These maps are used by the detector to apply FFC on images, before streaming them over
the data communications interface.
The Dark and Gain maps can be used by the host application to apply offset and gain
corrections to images captured from the detector. The host application may use the
“Teledyne X
-
Ray Processing Library” functions to apply such corrections, or for the
creation and uploading of new correction maps. This library and its API can be
downloaded from the Teledyne DALSA FTP server (ftp.teledynedalsa.com) on request.
FFC Calculation
The pixel value after FFC correction, FFCVal(x,y), is given by the following formula:
𝐹𝐹𝐶𝑉𝑎𝑙(𝑥, 𝑦) = [𝑃𝑖𝑥𝑒𝑙𝑉𝑎𝑙(𝑥, 𝑦) − 𝐷𝑎𝑟𝑘𝑉𝑎𝑙(𝑥, 𝑦)] ∗
𝐺𝑎𝑖𝑛𝑉𝑎𝑙(𝑥, 𝑦)
2
𝑈𝑛𝑖𝑡𝑦𝐺𝑎𝑖𝑛𝐹𝑎𝑐𝑡𝑜𝑟
+ 𝑂𝑓𝑓𝑠𝑒𝑡
FFCValue(x,y) Pixel value after FFC
PixelVal(x,y) Pixel value in raw image
DarkVal(x,y) Pixel value in Dark map
