Visible to Intel only — GUID: lrt1698316004831
Ixiasoft
Visible to Intel only — GUID: lrt1698316004831
Ixiasoft
24.3. Defective Pixel Correction IP Functional Description
The IP works on a 5x5 pixel neighborhood.
The color channel intensity sorter selects pixels closest to the center pixel and sorts them in order of their intensities. A filter calculates a corrected pixel value from the sorted group of pixels depending on the sensitivity level that you set.
The IP identifies and filters defect pixels dynamically and does not support static defect pixel correction. The sensitivity level determines the filtering strength. When you set the sensitivity level to the weakest value, the IP alters the pixel value only if its original value falls outside the value range of its 5x5 neighborhood. As the sensitivity increases, the range reduces closer to the median value. The IP passes the image unmodified if you set the Bypass bit in the CONTROL register.
You must set the color filter array phase to its correct value, which depends on the framing, rotation, and flipping options you apply to the original image that an imaging sensor captures. If you do not set the correct color filter array phase, the IP may mix color channels and produce incorrect outputs.
Information registers indicate how many pixels the IP modifies on any given frame by the IP. This information can indicate if the sensitivity setting is too high or whether the number of defective pixels is stable, or fluctuates depending on the conditions. These registers provide information about how many pixels are lower (PIX_LO_COUNTER) than the specified sensitivity setting or higher (PIX_HI_COUNTER) (refer to Defective Pixel Correction IP Registers). The IP instantiates these pair of registers for each Number of pixels in parallel. The IP shows the counter values of the instance that you select via PIP Clip Counter Selection value in the CONTROL register. You start updating the counter values by setting the Freeze Stats Request value in the CONTROL register. The IP counts the number of pixels it filters for exactly one frame. The IP sets Stats are Frozen bit of the STATUS register to indicate you may read the counter values. You should clear a previous freeze request and select the counter pair you want the IP to capture before starting a new freeze request.