Publicación: EFFECT OF MOISTURE CONTENT VARIATION ON CT IMAGE CLASSIFICATION TO IDENTIFY INTERNAL DEFECTS OF SUGAR MAPLE LOGS.
Fecha
2007
Autores
Título de la revista
ISSN de la revista
Título del volumen
Editor
FOREST PRODUCTS JOURNAL
Resumen
SUGAR MAPLE LOGS (ACER SACCHARUM MARSH.) WERE SCANNED WITH A MEDICAL X-RAY SCANNER IN ORDER TO EVALUATE THE RELATIONSHIP BETWEEN THE MOISTURE CONTENT (MC) AND THE PERFORMANCE OF A PARAMETRIC SUPERVISED CLASSIFICATION PROCEDURE TO DETECT INTERNAL DEFECTS. A FIRST GROUP OF LOGS COMING FROM FIVE TREES HARVESTED AT THE END OF MAY WAS SCANNED AFTER 0, 2, 6, 10, AND 14 WEEKS OF STORAGE. A SECOND GROUP OF LOGS COMING FROM FIVE TREES HARVESTED AT THE END OF AUGUST WAS SCANNED ONLY ONCE, IMMEDIATELY AFTER FELLING. THE CT IMAGES SELECTED FROM EACH LOG WERE CLASSIFIED AND FILTERED IN ORDER TO IDENTIFY AND SEPARATE THE SAPWOOD FROM OTHER INTERNAL CHARACTERISTICS. THE SAPWOOD AND OVERALL ACCURACIES WERE CALCULATED FROM A CONFUSION MATRIX THAT WAS DETERMINED FOR EACH IMAGE. FOR LOGS OF GROUP 1, THE STORAGE TIME RESULTED IN LOWER MC. NO SIGNIFICANT DIFFERENCES IN MC WERE OBSERVED BETWEEN GROUPS 1 AND 2 FOR THE FRESHLY CUT CONDITION. A QUADRATIC RELATIONSHIP WAS ESTABLISHED BETWEEN MC AND DETECTION ACCURACY FROM A REGRESSION ANALYSIS. THE COEFFICIENTS OF DETERMINATION (R 2) WERE 0.58 AND 0.42 FOR SAPWOOD AND OVERALL DETECTION ACCURACY, RESPECTIVELY. THE MAXIMUM SAPWOOD DETECTION ACCURACY WAS 0.93, WHICH WAS REACHED AT 62 PERCENT MC. BETWEEN 44 AND 67 PERCENT MC, SAPWOOD DETECTION ACCURACY EXCEEDED 0.80. THESE RESULTS INDICATE THAT THE MC VARIATIONS IN SUGAR MAPLE LOGS HAVE AN IMPORTANT IMPACT ON DEFECT-DETECTION CAPABILITY OF THIS METHOD
