电子科发女学光电科学与工程学院 SCHOOL OF OPTOELECTRONIC SCIENCE AND ENGINEERING OF UESTC 3,2 Some Basic Intensity Transformation Functions Agenda 1.Image Negatives 2.Log Transformations 3.Power-Law(Gamma)Transformations 4.Piecewise-Linear Transformation Functions
1. Image Negatives 2. Log Transformations 3. Power-Law (Gamma) Transformations 4. Piecewise-Linear Transformation Functions 3.2 Some Basic Intensity Transformation Functions Agenda
电子科发女学光电科学与工程学院 SCHOOL OF OPTOELECTRONIC SCIENCE AND ENGINEERING OF UESTC 3,2 Some Basic Intensity Transformation Functions FIGURE 3.3 Some L-1 basic intensity transformation Negative functions.All curves were nth root scaled to fit in the 3L/4 range shown. Log nth power LR L/4 Identity Inverse log 0 0 L/4 LR 3L4 L-1 Input intensity level,r
3.2 Some Basic Intensity Transformation Functions
电子科线女学光电科学与工程学院 SCHOOL OF OPTOELECTRONIC SCIENCE AND ENGINEERING OF UESTC 1.Image Negative S L-1 s=L-1-r White sl ..o(rl,s1) L=the number of gray levels s2 Q(r2,s2) 0r1 r2 L-1 Black Input intensity White
1. Image Negative L = the number of gray levels s L r = − −1 White Input intensity Output intensity 0 L-1 L-1 Black White r s (r1,s1) (r2,s2) r1 r2 s1 s2
电子科线女学光电科学与工程学院 SCHOOL OF OPTOELECTRONIC SCIENCE AND ENGINEERING OF UESTC 1.Image Negative ab FIGURE 3.4 (a)Original digital mammogram. (b)Negative image obtained using the negative transformation inEq.(3.2-1) (Courtesy of G.E. Medical Systems.)
1. Image Negative
电子科发女学光电科学与工程学院 SCHOOL OF OPTOELECTRONIC SCIENCE AND ENGINEERING OF UESTC 2.Log Transformations L-1 Negative nth root s clog(r+1) 3L/4 where c is a constant,and nth power it is assumed that r>0 Lp L/4 Identity Inverse log 0 L/4 LR 3L4 L-1 Input intensity level,r
2. Log Transformations s c r = + log( 1) ◼ where c is a constant, and it is assumed that r≥0