Dust is a problem with all cameras and often finds its way to the the imaging sensor. It is not uncommon for a camera to attract and collect dust and debris on the image sensor. Digital camera users need to be aware of this potential blemish issue.
Blemishes are visible spots or marks in the image, caused by sensor defects or by dust in front of the sensor (typically separated by the Bayer, anti-aliasing, and near infrared filters).
Our camera modules modified for NIR imaging is available in several different cosmetic grades, as shown below. Grade 1 is our standard modified camera module blemish specifications and thus suitable for Research and Development. Grade 1 is not suitable for critical application such as fundus imaging.
|Grade||Point Defects||Column Defects||Clusters Defects||Cluster Size|
Cosmetic Specifications Definition
|Point Defect||A black pixel or white pixel defect|
|Column Defect||A contiguous grouping of 10 or more white or black pixel defect pixels in a single column|
|Cluster Defect||A contiguous grouping of white or black pixel defects with a size less than or equal to Cluster Size|
|Black Pixel||A pixel with an amplitude less than 50% of the local mean when measured at half the pixel full well|
|White Pixel||A pixel with more than 10X the local dark signal|