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cvsorgcode

$ \bigcirc$Name


cvsorgcode Encode the origins of curves : return bit rate for lossless compression




$ \bigcirc$Command Synopsis


cvsorgcode C . . .



C : input curves

. (screen output) : output number of points

. (screen output) : output number of bits to code the origin of the curves

. (screen output) : compression rate (bit per point = B/N)




$ \bigcirc$Function Summary


double cvsorgcode (C , N , B )

Curves C ;

unsigned int *N ;

double *B ;




$ \bigcirc$Description


This module computes the bit rate needed to encode the origin points of the curves contained in the input set. The bit rate is given in bit per point, the number of points being the total number of points contained in all curves.

Two structures are considered to represent the coordinates of the origin points : a binary bitmap (a pixel is set to 1 if it is an origin point, or to n if it is a multiple origin point of multiplicity order n) and the sequence of the distances between two successive origin points, the points being scanned in the natural order (from left to right and up to down).

Several coding schemes are considered over all the following algorithms, to code the former structures : entropy coding, arithmetic coding, predictive arithmetic coding.

The bit rate returned by the function is the best bit rate over the two structures and over all coding schemes. The function outputs also the total number of points N and the number of bits B needed to code the structure.

Use the module cvsencode to get the total bit rate to encode a set of curves. See the module arencode2 for more information on the arithmetic coding algorithms.




$ \bigcirc$See Also


arencode2, fentropy.

cvsencode.


$ \bigcirc$Version 1.1


Last Modification date : Thu Jan 24 18:39:30 2002


$ \bigcirc$Author


Jacques Froment






next up previous contents index
Next: fencode Up: Reference Previous: cvsfrecode   Contents   Index
mw 2004-05-05