Blank image is a reference image that has been taken when there is no sample on the prism. It is used for normalizing the optical image for image detection and diagnostics.
Blank image is used when the chosen detection algorithm is IDS algorithm. The edge detection of this algorithm is based on the analysis of the normalized optical image. The changes caused by the sample and prism erosion are more easily detected in a normalized image. See the "no sample" image in Analyzing optical image. When there is no sample on the prism, this is the desired optical image.
There are three possible statuses for blank image:
- OK: The blank image is usable.
- Checksum error: No valid image available. Create a new blank image or restore factory image by pressing Restore factory image.
- Not applicable: Appears only if VD algorithm is used as detection algorithm.