Abstract: There is described a method of encrypting a set of 2D input data, preferably image data. The method comprises obtaining the hash value of a password and re-sizing the hash value to fit the size of the 2D input data. The re-sized data is transformed using an irreversible transform, and the output of the transform is then used to encode the 2D data.

Abstract: There is described a method for detecting the presence of skin tone in an image. A gray scale representation of a pixel within the image is provided. Next, a red chrominance independent representation for is provided for the pixel. Then, the two representations are analysed to determine whether a difference in value between the representations corresponds with a the presence of a skin tone value. The present invention provides a rapid skin tone detection classifier particularly useful for real time applications.

Abstract: A method is provided for analysing the self-similarity of an audio file. The method involves obtaining the audio spectrum envelope data of an audio file to be analysed; performing a clustering operation on the spectrum envelope data to produce a clustered set of data; for a first portion of the clustered data, performing a string matching operation on at least one other portion of the clustered data; and based on the results of the string matching operation, determining the at least one other portion of the clustered data most similar to said first portion of the clustered data. There is also provided a method of repairing an audio stream received over a network using similarity data to replace damaged or missing portions of data with similar “good” portions of data.

Abstract: There is described a method of encrypting a set of 2D input data, preferably image data. The method comprises obtaining the hash value of a password and re-sizing the hash value to fir the size of the 2D input data. The re-sized data is transformed using an irreversible transform, and the output of the transform is then used to encode the 2D data.

Abstract: There is described a method for detecting the presence of skin tone in an image. A gray scale representation of a pixel within the image is provided. Next, a red chrominance independent representation for is provided for the pixel. Then, the two representations are analysed to determine whether a difference in value between the representations corresponds with a the presence of a skin tone value. The present invention provides a rapid skin tone detection classifier particularly useful for real time applications.