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sampler cleanup

This commit is contained in:
Nicolas Robidoux 2010-06-03 01:35:33 +00:00
parent 332c6b478e
commit 7b8f0f7324
1 changed files with 15 additions and 29 deletions
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44
libvips/resample/lbb.cpp
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@ -89,9 +89,7 @@
* the course of her honours thesis, and by N. Robidoux, A. Turcotte
* and E. Daoust during Google Summer of Code 2009 (through two awards
* made to GIMP to improve GEGL).
*/
/*
*
* LBB is a novel method with the following properties:
*
* --LBB is a Hermite bicubic method: The bicubic surface is defined,
@ -294,18 +292,20 @@ lbbicubic( const double c00,
* comparisons and 34 "? :". If you can figure how to do this more
* efficiently, let us know.
*/
const double m6 = (dos_one <= tre_one) ? dos_one : tre_one ;
const double M6 = (dos_one <= tre_one) ? tre_one : dos_one ;
const double m7 = (dos_fou <= tre_fou) ? dos_fou : tre_fou ;
const double M7 = (dos_fou <= tre_fou) ? tre_fou : dos_fou ;
const double m1 = (dos_two <= dos_thr) ? dos_two : dos_thr ;
const double M1 = (dos_two <= dos_thr) ? dos_thr : dos_two ;
const double m2 = (tre_two <= tre_thr) ? tre_two : tre_thr ;
const double M2 = (tre_two <= tre_thr) ? tre_thr : tre_two ;
const double m6 = (dos_one <= tre_one) ? dos_one : tre_one ;
const double M6 = (dos_one <= tre_one) ? tre_one : dos_one ;
const double m7 = (dos_fou <= tre_fou) ? dos_fou : tre_fou ;
const double M7 = (dos_fou <= tre_fou) ? tre_fou : dos_fou ;
const double m3 = (uno_two <= uno_thr) ? uno_two : uno_thr ;
const double M3 = (uno_two <= uno_thr) ? uno_thr : uno_two ;
const double m4 = (qua_two <= qua_thr) ? qua_two : qua_thr ;
const double M4 = (qua_two <= qua_thr) ? qua_thr : qua_two ;
const double m5 = LBB_MIN( m1, m2 );
const double M5 = LBB_MAX( M1, M2 );
const double m10 = LBB_MIN( m6, uno_one );
const double M10 = LBB_MAX( M6, uno_one );
const double m11 = LBB_MIN( m6, qua_one );
@ -314,8 +314,6 @@ lbbicubic( const double c00,
const double M12 = LBB_MAX( M7, uno_fou );
const double m13 = LBB_MIN( m7, qua_fou );
const double M13 = LBB_MAX( M7, qua_fou );
const double m5 = LBB_MIN( m1, m2 );
const double M5 = LBB_MAX( M1, M2 );
const double m8 = LBB_MIN( m5, m3 );
const double M8 = LBB_MAX( M5, M3 );
const double m9 = LBB_MIN( m5, m4 );
@ -613,35 +611,23 @@ lbbicubic( const double c00,
/*
* Part of the result which does not need derivatives:
*/
const double newval1 =
( c00 * dos_two + c10 * dos_thr )
+
( c01 * tre_two + c11 * tre_thr );
const double newval1 = c00 * dos_two + c10 * dos_thr +
c01 * tre_two + c11 * tre_thr;
/*
* Twice the part of the result which only needs first derivatives.
*/
const double newval2 =
(
( c00dx * dble_dzdx00 + c10dx * dble_dzdx10 )
+
( c01dx * dble_dzdx01 + c11dx * dble_dzdx11 )
)
+
(
( c00dy * dble_dzdy00 + c10dy * dble_dzdy10 )
+
( c01dy * dble_dzdy01 + c11dy * dble_dzdy11 )
);
const double newval2 = c00dx * dble_dzdx00 + c10dx * dble_dzdx10 +
c01dx * dble_dzdx01 + c11dx * dble_dzdx11 +
c00dy * dble_dzdy00 + c10dy * dble_dzdy10 +
c01dy * dble_dzdy01 + c11dy * dble_dzdy11;
/*
* Four times the part of the result which only uses cross
* derivatives:
*/
const double newval3 =
( c00dxdy * quad_d2zdxdy00 + c10dxdy * quad_d2zdxdy10 )
+
( c01dxdy * quad_d2zdxdy01 + c11dxdy * quad_d2zdxdy11 );
const double newval3 = c00dxdy * quad_d2zdxdy00 + c10dxdy * quad_d2zdxdy10 +
c01dxdy * quad_d2zdxdy01 + c11dxdy * quad_d2zdxdy11;
const double newval = newval1 + .5 * newval2 + .25 * newval3;