network 502 the routing network uses as its inputs the coefficients resulting from the decompositions performed by the module 501 a multiplexer 504 is used to select the coefficients cs at the output of the architecture thus when level one decomposition is in progress the output of the unit 500 is selected whereas when decomposition at level two or above is in progress it is the output of the unit 502 that is selected advantageously this architecture permits optimal hardware utilization with low main storage requirements fig6 shows an example of a row processing module rpe that can be used for the level one decomposition the 2d wavelet transform is obtained by the successive application of vertical and horizontal transforms without an intermediate buffer memory the rpe row processing element transform unit executes the horizontal transform it incorporates two registers 600 601 for storing the intermediate coefficients required for the calculations two addition operators 602 603 and a 3 bit shift operator are used for calculating the coefficients control of the operations and paths is provided by multiplexers 604 605 606 607 608 the state of which depends on the parity of the current row fig7 shows an example of a column processing module rce that can be used for the level one decomposition this unit is used for the vertical transform it resembles the horizontal transform unit but with the two registers 600 601 replaced with two row memories 700 701 providing read access and write access for each cycle for the decomposition of the higher levels as explained above a second decomposition unit 501 is responsible for.