Visibility of DCT Basis Functions: Effects of Contrast Masking
نویسندگان
چکیده
INTRODUCTION DCT image compression. The discrete cosine transform (DCT) is a standard method by which images may be compressed. Initially, the image is divided into 8x8-pixel blocks, each of which is then transformed into its DCT, which is an 8x8 matrix of coefficients. Each coefficient cij , specifies the magnitude of a DCT frequency (or basis function), indexed by i, j . For brevity, we adopt a vector notation for the frequencies, so U = { i , j } and cU = cij . Image
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