and codes a corresponding bit of each coefficient in each second area of the current bitplane application_number US 42718199 A description where reference is made in any one or more of the accompanying drawings to steps and or features which have the same reference numerals those steps and or features have for the purposes of this description the same function s or operation s unless the contrary intention appears the principles of the preferred method have general applicability to the encoding and decoding of a block of coefficients for ease of explanation the preferred method is described with reference to the encoding and decoding of a block of transform coefficients of an image and it it is not intended to be limited thereto the method has also been described with reference to a number of specific examples of images and it is also not intended that the invention be limited to such specific examples the preferred method proceeds initially by means of a wavelet transform of image data an overview of the wavelet process will now be described with reference to the accompanying drawings referring initially to fig1 a and 1b an original image 1 is transformed utilizing a discrete wavelet transform dwt into four sub images 3 6 the sub images or subbands are normally denoted by ll 1 hl 1 lh 1 and hh 1 the one suffix on the subband names indicates level 1 the ll 1 subband is a low pass decimated version of the original image the wavelet transform utilized can vary and can include for example haar basis functions.