Recently, according to the inside of the matlab wavelet transform of DWT functions written in c program, although able to decompose and reconstruct the original data, but found in the process of decomposition of low frequency component and the length of the high frequency component is not half as long as the original data
Raw data length is 16, for example, after the layer after db3 wavelet decomposition, the length of the low frequency and high frequency components, respectively, 11 is not half as long as the original data - 8, urgent seek expert told what to do to get the length of the low frequency and high frequency components is half the length of the original data