1. Image transform apparatus for processing pixel image data, comprising: at least one low pass extractor for extracting a low pass component from a series of image pixels, at least one low pass downsampler associated with said at least one low pass extractor for producing downsampled versions of respective extracted low pass components, at least one high pass extractor for extracting a high pass component from a series of image pixels, at least one high pass downsampler associated with said at least one high pass extractor for producing downsampled versions of respective extracted low pass components, and control and iteration circuitry associated with said low pass extractor and said high pass extractor for: feeding complementary sets of pixels from an image to said respective extractors, receiving respective low and high pass components from respective high and low pass downsamplers, and iteratively feeding complementary sets of pixels from a downsampled version of a most recently formed low pass component to respective high and low pass extractors and receiving further respective low and high pass components until a stop condition is reached.