ALLIED Vision Technologies Stingray F-504 - Manual (Page 145)

Description of the data path
STINGRAY Technical Manual V4.4.4
143
Building defect pixel data
To build defect pixel data perform the following steps:
Grab an image with defect pixel data
1. Take the camera, remove lens and put on lens cap.
2. Set image resolution to Format_7 Mode_x or Format_7 Mode_0 (when
using fixed modes) and set AOI to maximum.
3. Set values for shutter and gain to max.
4. Grab a single image (one-shot).
Calculate defect pixel coordinates
5. Accept default threshold from system or choose own threshold.
6. Set the BuildDPData flag to 1.
In microcontroller the defect pixel calculation is started. The detected
defect pixel coordinates are stored in the dual port RAM of the FPGA.
Note

• Defect pixel detection is only possible in Mono8/
Raw8 modes. In all other modes you get an error
message in advanced register 0xF1000298 bit [1] see
Table 142: Advanced register: Defect pixel correction on
page 312.
• Using Format_7 Mode_x: Defect pixel detection is done
in Format_7 Mode_x.
• Using a fixed format (Format_0, Format_1 or
Format_2): Defect pixel detection is done in Format_7
Mode_0.
• When using defect pixel correction with binning and
sub-sampling: first switch to binning/sub-sampling
mode and then apply defect pixel detection.
• Optional: To improve the quality of defect pixel
detection, activate HSNR mode additionally.
• There is a maximum of 256 defect pixels that can be
found. If the algorithm detects more defect pixels, then
it will end with an error. For more details, see
DPDataSize register on page 313.
Note

A mean value is calculated over the entire image that is
grabbed internal.
Definition: A defect pixel is every pixel value of this
previously grabbed image that is:
• greater than (mean value + threshold)
or
• less than (mean value - threshold)