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fvalues

$ \bigcirc$Name


fvalues Get and sort all the pixel values of a fimage




$ \bigcirc$Command Synopsis


fvalues [-i] [-m multiplicity] [-r rank] image_in values



-i : decreasing values (default is increasing)

-m multiplicity : output the multiplicity of the values (fsignal)

-r rank : output rank of each pixel value in ordered list (fimage)

image_in : input fimage

values : output list of sorted values (fsignal)




$ \bigcirc$Function Summary


Fsignal fvalues (i_flag , multiplicity , image_rank , image_in )

char *i_flag ;

Fsignal multiplicity ;

Fimage image_rank ;

Fimage image_in ;




$ \bigcirc$Description


Let NC=image_in->ncol and NL=image_in->nrow, then the image image_in is defined by the set of pixels {g(i, j) / i = 0,..., NC , j = 0,..., NL}. The module fvalues computes the range of the function g  : [0, NC - 1]×[0, NL - 1] $ \longrightarrow$ IR.

The output is an fsignal of size N + 1, with float values {v0, v1,..., vN}, where N + 1 is the number of different values in image_in ( 1 $ \leq$ N + 1 $ \leq$ NC*NL).

The module uses a heap sort to put the values in increasing order and decreasing if the -i flag is set.

The -m option allows to save the multiplicities of the corresponding values in values into the fsignal multiplicity and thus allows to compute the histogram of image_in.

The -r option computes an fimage rank, this array contains the indexes of the gray values in the ordered list values, i.e. the rank of a pixel's gray value.

Example : if g(i, j) = vn then values[n] = vn and rank(i, j) = n, moreover multiplicity[n] gives the number of occurrences of the value vn in the image.




$ \bigcirc$See Also


bicontrast, fentropy, finfo, frank, ml_decompose, osamss, ridgthres.


$ \bigcirc$Version 4.2


Last Modification date : Mon Feb 11 14:35:25 2002


$ \bigcirc$Author


Georges Koepfler






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