Spectral response of the discrete cosine and Walsh-Hadamard transforms

摘要: It is becoming increasingly popular, when considering transform coding schemes for images, to attempt take the spatial frequency response of human observer into account by performing a classical one- or two-dimensional filtering (pre-emphasis) operation upon coefficients Fourier transformed image, and it would be advantageous if such procedure could carried out with more commonly used image transforms, notably discrete cosine Walsh-Hadamard transforms. demonstrated here that, notwithstanding theoretical difficulties associated convolution/multiplication where concerned, its spectral nature appropriate characteristic are that an above mentioned kind may out, benefits psychovisual obtained. On other hand, results obtained in case show unlikely performance will found satisfactory application.