Hewlett-packard Company

Dome Imaging Systems, Inc.

John Paul Beck

Ruby B Lee

To compress a digitized medical image, a first wavelet including quadrants respectively having LL, LH, HL and HH frequencies is provided, preferably in parallel. L and H respectively represent low and high frequency ranges. L and H representations may be respectively provided by averaging, and taking the difference between, two (2) successive pixels values. The first and second letters in each quadrant respectively refer to the frequency range in a pair of co-ordinates. A second wavelet may include, in the first wavelet LL quadrant, quadrants respectively having LL, LH, HL and HH frequency ranges. Successive wavelets may be similarly provided. Each wavelet is provided from the LL quadrant of the previous wavelet because most of the frequency information resides in the LL quadrant. Individual compressions may be provided in parallel of the representations in the LH, HL and HH quadrants in the first wavelet, preferably on a lossy basis (e.g. discrete cosine transform and then Huffman coding). An individual compression may be simultaneously provided of the LL representation in the first wavelet and the LL, LH, HL and HH representations in the second wavelet, preferably on a lossless basis (e.g. Huffman coding). Decompression may be provided by performing the inverse of compression. The pixels may be restored after decompression by reconstructing the pixels from the wavelets in steps inverse to those in obtaining the wavelets. Thus, the information transmissions time is minimized with little reduction loss.

Method of producing wavelets and compressing digital images and of

An apparatus that can also be used for generating the average of two integers. The apparatus can be divided into a plurality of sub-adders that operate on sub-words of the input integers in parallel. Hence, the adder can be used for adding or subtracting one set of two integers wherein each integer is of some predetermined length or a plurality of sets of two integers provided the sum of the lengths of the integers is less than or equal to this predetermined length. The apparatus can also generate the sum, or difference, of each of the sub-words divided by two. The parallel operations can be carried out in response to a single instruction. The results of the division by two are rounded in a manner that eliminates biasing of the results.

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Tyngsborough, MA, United States of America

John Paul Beck