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im_stats() and im_deviate() done

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This commit is contained in:
John Cupitt 2009-09-08 11:25:38 +00:00
parent f302d023db
commit 5901a7ca87
2 changed files with 14 additions and 50 deletions
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17
libvips/arithmetic/im_deviate.c
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@ -169,8 +169,8 @@ deviate_scan( void *in, int n, void *seq, void *a, void *b )
g_assert( 0 );
}
ss2[0] += s;
ss2[1] += s2;
ss2[0] = s;
ss2[1] = s2;
return( 0 );
}
@ -194,7 +194,8 @@ int
im_deviate( IMAGE *in, double *out )
{
double global_ss2[2];
gint64 N;
double s, s2;
gint64 vals;
/* Check our args.
*/
@ -208,7 +209,8 @@ im_deviate( IMAGE *in, double *out )
global_ss2[0] = 0.0;
global_ss2[1] = 0.0;
if( im__wrapscan( in,
deviate_start, deviate_scan, deviate_stop, in, &global_ss2 ) )
deviate_start, deviate_scan, deviate_stop, in, global_ss2 ) )
return( -1 );
/*
@ -220,9 +222,10 @@ im_deviate( IMAGE *in, double *out )
/* Calculate and return deviation. Add a fabs to stop sqrt(<=0).
*/
N = (gint64) in->Xsize * in->Ysize * in->Bands;
*out = sqrt( fabs( global_ss2[1] -
(global_ss2[0] * global_ss2[0] / N) ) / (N - 1) );
vals = (gint64) in->Xsize * (gint64) in->Ysize * (gint64) in->Bands;
s = global_ss2[0];
s2 = global_ss2[1];
*out = sqrt( fabs( s2 - (s * s / vals) ) / (vals - 1) );
return( 0 );
}

47
libvips/arithmetic/im_stats.c
View File

@ -164,46 +164,7 @@ stats_scan( void *in, int n, void *seq, void *a, void *b )
/* Now generate code for all types.
*/
switch( im->BandFmt ) {
case IM_BANDFMT_UCHAR:
/*
LOOP( unsigned char ); break;
*/
for( z = 0; z < im->Bands; z++ ) {
PEL *q = (PEL *) in + z;
double *row = stats + z * 4;
PEL small, big;
double sum, sum2;
printf( "z = %d\n", z );
small = row[0];
big = row[1];
sum = row[2];
sum2 = row[3];
for( x = 0; x < n; x++ ) {
PEL value = *q;
printf( "value = %d\n", value );
sum += value;
sum2 += (double) value * (double) value;
if( value > big )
big = value;
else if( value < small )
small = value;
q += im->Bands;
}
row[0] = small;
row[1] = big;
row[2] = sum;
row[3] = sum2;
}
break;
case IM_BANDFMT_UCHAR: LOOP( unsigned char ); break;
case IM_BANDFMT_CHAR: LOOP( signed char ); break;
case IM_BANDFMT_USHORT: LOOP( unsigned short ); break;
case IM_BANDFMT_SHORT: LOOP( signed short ); break;
@ -230,7 +191,7 @@ im_stats( IMAGE *im )
{
DOUBLEMASK *out;
double *row;
gint64 pels, vals, z;
gint64 pels, vals;
double *global_stats;
int i, j;
double value;
@ -255,7 +216,7 @@ im_stats( IMAGE *im )
* separately.
*/
if( im__wrapscan( im, stats_start, stats_scan, stats_stop,
im, &global_stats ) )
im, global_stats ) )
return( NULL );
/* Calculate mean, deviation, plus overall stats.
@ -274,7 +235,7 @@ im_stats( IMAGE *im )
vals = pels * im->Bands;
for( i = 0; i < im->Bands; i++ ) {
row = out->coeff + (z + 1) * 6;
row = out->coeff + (i + 1) * 6;
for( j = 0; j < 4; j++ )
row[j] = global_stats[i * 4 + j];