Copyright ©2008 T. H. Merrett COMP 617 Information Systems Winter 2008 Week 1 II Fourier-transformed sequences (See www.cs.mcgill.ca/~tim/cs199/notes09.pdf notes 1--4) Str(seq term) DFT(freq coeff ) StrApp(seq term) 1 1 0 2.0 <-1 1 1 2 1 1 0.08+0.41i 2 1 3 1 2 0.18+0.43i <-5 3 0 <- 4 0 3 0.05+0.08i 4 0 5 1 4 0.75+0.75i <-2 5 1 6 1 5 -0.41-0.27i <-4 6 1 7 0 6 -0.18-0.07i 7 0 8 0 7 0.27+0.05i 8 0 9 1 8 0.50 <-3 9 1 10 1 9 0.27-0.05i 10 1 11 0 10 -0.18+0.07i 11 0 12 0 11 -0.41+0.27i 12 0 13 1 12 0.75-0.75i 13 1 14 0 13 0.05-0.08i 14 1 <- 15 0 14 0.18-0.43i 15 0 16 0 15 0.08-0.41i 16 0 DFTapp(freq coeff ) 0 2.0 4 0.75+0.75i (original image) (JPEG image) 1100 1100 1100 0100 1100 1101 1100 1100 seek 1(0|1)01 seek (1100)* 1100