Dear IDL USERS I would like your advice to a problem that i have with IDL + WAVELET transform I have transform an RGB image to YCbCr, and i keep the Y in a matix , lets say Y[352 , 240] I want to compute the wavelet matrix from array Y , the way JPEG2000 does it For lossy compression, the default wavelet filter used in the JPEG2000 standard is the Daubechies (9, 7) biorthogonal spline filter. By (9, 7) we indicate that the analysis filter is formed by a 9-tap low-pass FIR filter and a 7-tap high-pass FIR filter. according to IDL manual this can be done with th following commands info = WV_FN_DAUBECHIES(2, wavelet, scaling, ioff, joff) wv_dwtpartial = WV_DWT(Y, wavelet, scaling, ioff, joff, N_LEVELS=5) 1. Is this the correct way of doing it??? 2. When i give the dimensions 352,240 it gives e a message that dimensions must be a power of 2 so i am taking another matrix Y1[512,521] so that y1[0:351,0:239]=y[0:351,0:249] When i am doing the above procedure i am getting a matrix with the wavelets coefficients (???) but when i try to visualize the image giving the following commands LOADCT, 0 TV, wv_dwtpartial[0:351,0:239] i am not getting the expected image.. Could you please help me??? Thank You in Advance Kostas I. Koumousis