Achieving compression with high-quality reconstructed US colour and grey images at reduced sampling rate

This paper is an endeavour to reduce the number of measurements to be taken in medical imaging, so as to reduce radiation exposure given to an ailing patient and at the same time achieve higher compression ratio (CR) under the case when sampling rate is lesser than the Nyquist rate. The obtained rate of compression in grey and colour US images has been compared. Colourization method has been applied on US colour images. Suitable modifications have been proposed in the colourisation method to extract colour representative pixels (RPs). The reconstructed grey and colour image quality has been evaluated using peak signal-to-noise ratio, structural similarity index, feature similarity index and mean square error parameters at different CR. It has been shown that an acceptable quality of US colour images can be reconstructed with 75% CR, whereas grey image is reconstructed satisfactorily with 50% CR.