Below is an image of a portion of a board after GradeScan identified season checks. The board actually has several season checks in the center of the board and a small scratch under the knot on the left hand side. The scratch was caused by something, maybe a pebble, that got caught between two boards and was rubbed across the wide face. It is a blemish that is not regarded as a defect. All the surface checks, including the short ones in the middle of the flat grain that are less than 0.010" wide, were identified.
GradeScan's Season Check Finder correctly identifies the check but does not get confused by the scratch.
The next example shows a portion of a board with a long surface shake and a crack in a knot head. The image on the right shows the board after GradeScan applied its Shake Finder. The checking inside the knot head did not confuse the Shake Finder.
This next shake ran off the end of the board and passed into the other wide face through the end. GradeScan called it an End Split. Some mills look for small ties of material to separate long shakes and splits. Other mills want to put shakes and splits that close into one long defect. GradeScan can do either method, it's your choice.