A method of and arrangement for digitizing a video signal using a picture transform coding, wherein a group of N video signal samples is converted into a group of N coefficients y(m) wherein m=1, 2, 3, . . . N which are each adaptively encoded. In order to prevent a coefficient y(m) which is on average small to very small, from being insufficiently accurately encoded, or not encoded at all, when it is occasionally large, the group of coefficients is compared with a number of fixed classification groups A(j) each consisting of M elements a(j,m), wherein a(j+l,m)/=a(j,m) and j=1, 2, 3, . . . M. The j is determined in such manner that y(m)a(j,m) for all m. A bit-assignment group B(j) having elements b(j,m) is associated with each classification group A(j) and each one of the N coefficients y(m) is now converted into a code word z(m) which contains a number of bits which is characterized by b(j,m) and which is, for example, equal to the value of b(j,m).
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