rms

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Name

rms - root mean square difference between two bands

Syntax

 #include <xite/arithmetic.h>

 double rms( IBAND band1, IBAND band2,
    int edge );

Description

The root mean square difference between the two input bands is calculated and written to stdout.

 rms = SQRT{ SUM [ |band1[y][x] - band2[y][x]| **2 ] / N }

where SUM is over all N pixels in the band minus an edge of width edge which is not included in the calculaton. The purpose of this is to exclude differences due to different processing of the edge by local filters.

All pixeltypes are allowed, but band1 and band2 must be of the same pixeltype.

Return value

 >= 0 : The rms difference
 -1   : Different pixeltypes in the two bands
 -2   : Unknown pixeltype

See also

rms(1), absDiff(3), signDiff(3)

Author

Tor Lønnestad, BLAB, Ifi, UiO.

Modified

Svein Bøe, allowing all pixeltypes.

Id

$Id: rms.c,v 1.30 1997/05/27 14:47:12 svein Exp $