IMPROVED LOG SCANNING

A log scanning system applies circumferentially spaced, traverse scans along the length of the log to provide a longitudinal density scan for each of the scans made. Each scan is made up of rows of density dependent pixels sensed by specific detector (scan line) and columns of density dependent pixels sensed by adjacent detectors arranged transversely of the log. The signals generated along each row to are filtered to produce a clean signal scan line and each clean scan line is processed to determine positive peaks. The positive peaks are plotted to form an image and adjacent peaks in adjacent rows and columns are joined to provide a spine image depicting spines of detected knots in each scan. Knot shapes are then defined by reprocessing each scan along the rows or scan lines to determine the knot boundaries on each side of each of the spine lines based on pixels displaying a selected minimum density and these shapes applied to the spine image to provide a reconstructed scan. The longitudinal axis of the log is determined and applied to the reconstructed scans to define the roots or inner ends of the knots. The reconstructed scans are then used to define the same knot in each of the reconstructed scans and then to generate a three-dimensional image of the log which may then be used by a sawing program to determine how the log should be sawed.