nohalo resampler simplification/speed up

This commit is contained in:
Nicolas Robidoux 2009-03-04 22:09:54 +00:00
parent 2de4a0db09
commit b23a1ece6c

View File

@ -5,19 +5,20 @@
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
VIPS is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
You should have received a copy of the GNU Lesser General Public
License along with this program; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA
*/
@ -30,15 +31,16 @@
/*
* 2009 (c) Nicolas Robidoux
*
* Thanks: Geert Jordaens, John Cupitt, Minglun Gong, Øyvind Kolås and
* Sven Neumann for useful comments and code.
* Nicolas thanks Geert Jordaens, John Cupitt, Minglun Gong, Øyvind
* Kolås and Sven Neumann for useful comments and code.
*
* Acknowledgement: Nicolas Robidoux's research on nohalo funded in
* part by an NSERC (National Science and Engineering Research Council
* of Canada) Discovery Grant.
* Nicolas Robidoux's research on nohalo funded in part by an NSERC
* (National Science and Engineering Research Council of Canada)
* Discovery Grant.
*/
/* Hacked for vips by J. Cupitt, 20/1/09
* Tweaks by N. Robidoux, 03/3/09
*/
/*
@ -63,9 +65,9 @@
* not change the answer, and consequently do not increase its
* quality.
*
* ============================================================
* WARNING: THIS CODE ONLY IMPLEMENTS THE LOWEST QUALITY NOHALO
* ============================================================
* ===================================================
* THIS CODE ONLY IMPLEMENTS THE LOWEST QUALITY NOHALO
* ===================================================
*
* This code implement nohalo for (quality) level = 1. Nohalo for
* higher quality levels will be implemented later.
@ -114,11 +116,7 @@
*
* The value of the reconstructed intensity surface at any point
* depends on the values of (at most) 12 nearby input values, located
* in a "cross" centered at the closest four input pixel centers. For
* computational expediency, the input values corresponding to the
* nearest 21 input pixel locations (5x5 minus the four corners)
* should be made available through a data pointer. The code then
* selects the needed ones from this enlarged stencil.
* in a "cross" centered at the closest four input pixel centers.
*
* ===========================================================
* When level = infinity, nohalo's intensity surface is smooth
@ -140,25 +138,26 @@
*
* (Except possibly near the boundary: it is easy to make this
* property carry over everywhere but this requires a tuned abyss
* policy or building the boundary conditions inside the sampler.)
* Nohalo is exact on linear intensity profiles, meaning that if the
* input pixel values (in the stencil) are obtained from a function of
* the form f(x,y) = a + b*x + c*y (a, b, c constants), then the
* computed pixel value is exactly the value of f(x,y) at the
* asked-for sampling location. The boundary condition which is
* emulated by VIPS throught the "extend" extension of the input
* image---this corresponds to the nearest neighbour abyss
* policy---does NOT make this resampler exact on linears at the
* boundary. It does, however, guarantee that no clamping is required
* even when resampled values are computed at positions outside of the
* extent of the input image (when extrapolation is required).
* policy---linear extrapolation, say---or building the boundary
* conditions inside the sampler.) Nohalo is exact on linear
* intensity profiles, meaning that if the input pixel values (in the
* stencil) are obtained from a function of the form f(x,y) = a + b*x
* + c*y (a, b, c constants), then the computed pixel value is exactly
* the value of f(x,y) at the asked-for sampling location. The
* boundary condition which is emulated by VIPS throught the "extend"
* extension of the input image---this corresponds to the nearest
* neighbour abyss policy---does NOT make this resampler exact on
* linears at the boundary. It does, however, guarantee that no
* clamping is required even when resampled values are computed at
* positions outside of the extent of the input image (when
* extrapolation is required).
*
* ===================
* Nohalo is nonlinear
* ===================
*
* In particular, resampling a sum of images may not be the same as
* summing the resamples (this occurs even without taking into account
* summing the resamples. (This occurs even without taking into account
* over and underflow issues: images can only take values within a
* banded range, and consequently no sampler is truly linear.)
*
@ -188,10 +187,6 @@
* intensity surface can be treated as if smooth.)
*/
/*
#define DEBUG
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
@ -274,260 +269,236 @@ typedef struct _VipsInterpolateNohaloClass {
} VipsInterpolateNohaloClass;
/* Calculate the four results surrounding the target point, our caller does
* bilinear interpolation of them.
*/
static void inline
nohalo_sharp_level_1(
const double uno_two,
const double uno_thr,
const double dos_one,
const double dos_two,
const double dos_thr,
const double dos_fou,
const double tre_one,
const double tre_two,
const double tre_thr,
const double tre_fou,
const double tre_fiv,
const double qua_two,
const double qua_thr,
const double qua_fou,
const double qua_fiv,
const double cin_thr,
const double cin_fou,
double *r1,
double *r2,
double *r3 )
{
/* Start of copy-paste from Nicolas's source.
*/
/*
* THE ENLARGED STENCIL (prior to entering this function):
*
* The potentially needed input pixel values are described by the
* following stencil, where (ix,iy) are the coordinates of the
* closest input pixel center (with ties resolved arbitrarily).
*
* Spanish abbreviations are used to label positions from top to
* bottom (rows), English ones to label positions from left to right
* (columns).
*
* (ix-1,iy-2) (ix,iy-2) (ix+1,iy-2)
* = uno_two = uno_thr = uno_fou
*
* (ix-2,iy-1) (ix-1,iy-1) (ix,iy-1) (ix+1,iy-1) (ix+2,iy-1)
* = dos_one = dos_two = dos_thr = dos_fou = dos_fiv
*
* (ix-2,iy) (ix-1,iy) (ix,iy) (ix+1,iy) (ix+2,iy)
* = tre_one = tre_two = tre_thr = tre_fou = tre_fiv
*
* (ix-2,iy+1) (ix-1,iy+1) (ix,iy+1) (ix+1,iy+1) (ix+2,iy+1)
* = qua_one = qua_two = qua_thr = qua_fou = qua_fiv
*
* (ix-1,iy+2) (ix,iy+2) (ix+1,iy+2)
* = cin_two = cin_thr = cin_fou
*
* THE STENCIL OF ACTUALLY READ VALUES:
*
* The above is the "enlarged" stencil: about half the values will
* not be used. Once symmetry has been used to assume that the
* sampling point is to the right and bottom of tre_thr---this is
* done by implicitly reflecting the data if needed---the actually
* used input values are named thus:
*
* dos_thr dos_fou
*
* tre_two tre_thr tre_fou tre_fiv
*
* qua_two qua_thr qua_fou qua_fiv
*
* cin_thr cin_fou
*
* (If, for exammple, relative_x_is_left is 1 but relative_y_is___up
* = 0, then dos_fou in this post-reflexion reduced stencil really
* corresponds to dos_two in the "enlarged" one, etc.)
*
* Given that the reflexions are performed "outside of the
* nohalo_sharp_level_1 function," the above 12 input values are the
* only ones which are read from the buffer.
* This function calculates the missing three double density pixel
* values. The caller does bilinear interpolation on them and
* dos_two.
*/
/*
* THE STENCIL OF INPUT VALUES:
*
* Nohalo's stencil is the same as, say, Catmull-Rom, with the
* exception that the four corner values are not used:
*
* (ix-1,iy-2) (ix,iy-2)
* = uno_two = uno_thr
*
* (ix-2,iy-1) (ix-1,iy-1) (ix,iy-1) (ix+1,iy-1)
* = dos_one = dos_two = dos_thr = dos_fou
*
* (ix-2,iy) (ix-1,iy) (ix,iy) (ix+1,iy)
* = tre_one = tre_two = tre_thr = tre_fou
*
* (ix-1,iy+1) (ix,iy+1)
* = qua_two = qua_thr
*
* The indices associated with the values shown above are in the
* case that the resampling point is closer to (ix-1,iy-1) than the
* other three central positions. Pointer arithmetic is used to
* implicitly reflect the input stencil in the other three cases,
* For example, if the sampling position is closer to dos_two (that
* is, if relative_x_is_rite = 1 but relative_y_is_down = 0 below),
* then dos_two corresponds to (ix,iy-1), dos_thr corresponds to
* (ix-1,iy-1) etc. Consequently, the three missing double density
* values are halfway between dos_two and dos_thr, halfway between
* dos_two and tre_two, and at the average of the four central
* positions.
*/
/*
* Computation of the nonlinear slopes: If two consecutive pixel
* value differences have the same sign, the smallest one (in
* absolute value) is taken to be the corresponding slope; if the
* two consecutive pixel value differences don't have the same sign,
* the corresponding slope is set to 0.
* the corresponding slope is set to 0. (In other words, apply
* minmod to comsecutive slopes.)
*/
/*
* Dos(s) horizontal differences:
*/
const double prem_dos = dos_two - dos_one;
const double deux_dos = dos_thr - dos_two;
const double troi_dos = dos_fou - dos_thr;
/*
* Tre(s) horizontal differences:
*/
const double prem_tre = tre_two - tre_one;
const double deux_tre = tre_thr - tre_two;
const double troi_tre = tre_fou - tre_thr;
const double quat_tre = tre_fiv - tre_fou;
/*
* Qua(ttro) horizontal differences:
* Two vertical differences:
*/
const double deux_qua = qua_thr - qua_two;
const double troi_qua = qua_fou - qua_thr;
const double quat_qua = qua_fiv - qua_fou;
const double prem_two = dos_two - uno_two;
const double deux_two = tre_two - dos_two;
const double troi_two = qua_two - tre_two;
/*
* Thr(ee) vertical differences:
*/
const double prem_thr = dos_thr - uno_thr;
const double deux_thr = tre_thr - dos_thr;
const double troi_thr = qua_thr - tre_thr;
const double quat_thr = cin_thr - qua_thr;
/*
* Fou(r) vertical differences:
*/
const double deux_fou = tre_fou - dos_fou;
const double troi_fou = qua_fou - tre_fou;
const double quat_fou = cin_fou - qua_fou;
/*
* Tre:
*/
const double half_sign_deux_tre = deux_tre >= 0. ? .5 : -.5;
const double half_sign_troi_tre = troi_tre >= 0. ? .5 : -.5;
const double half_sign_quat_tre = quat_tre >= 0. ? .5 : -.5;
/*
* Qua:
*/
const double half_sign_deux_qua = deux_qua >= 0. ? .5 : -.5;
const double half_sign_troi_qua = troi_qua >= 0. ? .5 : -.5;
const double half_sign_quat_qua = quat_qua >= 0. ? .5 : -.5;
/*
* Thr:
*/
const double half_sign_deux_thr = deux_thr >= 0. ? .5 : -.5;
const double half_sign_troi_thr = troi_thr >= 0. ? .5 : -.5;
const double half_sign_quat_thr = quat_thr >= 0. ? .5 : -.5;
/*
* Fou:
*/
const double half_sign_deux_fou = deux_fou >= 0. ? .5 : -.5;
const double half_sign_troi_fou = troi_fou >= 0. ? .5 : -.5;
const double half_sign_quat_fou = quat_fou >= 0. ? .5 : -.5;
/*
* Useful later:
*/
const double tre_thr_plus_tre_fou = tre_thr + tre_fou;
const double tre_thr_plus_qua_thr = tre_thr + qua_thr;
const double qua_fou_minus_tre_thr = qua_fou - tre_thr;
const double dos_two_plus_dos_thr = dos_two + dos_thr;
const double dos_two_plus_tre_two = dos_two + tre_two;
/*
* Dos:
*/
const double half_sign_prem_dos = prem_dos >= 0. ? .5 : -.5;
const double half_sign_deux_dos = deux_dos >= 0. ? .5 : -.5;
const double half_sign_troi_dos = troi_dos >= 0. ? .5 : -.5;
/*
* Tre:
*/
const double half_sign_prem_tre = prem_tre >= 0. ? .5 : -.5;
const double half_sign_deux_tre = deux_tre >= 0. ? .5 : -.5;
const double half_sign_troi_tre = troi_tre >= 0. ? .5 : -.5;
/*
* Two:
*/
const double half_sign_prem_two = prem_two >= 0. ? .5 : -.5;
const double half_sign_deux_two = deux_two >= 0. ? .5 : -.5;
const double half_sign_troi_two = troi_two >= 0. ? .5 : -.5;
/*
* Thr:
*/
const double half_sign_prem_thr = prem_thr >= 0. ? .5 : -.5;
const double half_sign_deux_thr = deux_thr >= 0. ? .5 : -.5;
const double half_sign_troi_thr = troi_thr >= 0. ? .5 : -.5;
/*
* Dos:
*/
const double half_abs_prem_dos = half_sign_prem_dos * prem_dos;
const double sign_dos_two_horizo = half_sign_prem_dos + half_sign_deux_dos;
const double half_abs_deux_dos = half_sign_deux_dos * deux_dos;
const double sign_dos_thr_horizo = half_sign_deux_dos + half_sign_troi_dos;
const double half_abs_troi_dos = half_sign_troi_dos * troi_dos;
/*
* Two:
*/
const double half_abs_prem_two = half_sign_prem_two * prem_two;
const double sign_dos_two_vertic = half_sign_prem_two + half_sign_deux_two;
const double half_abs_deux_two = half_sign_deux_two * deux_two;
const double sign_tre_two_vertic = half_sign_deux_two + half_sign_troi_two;
const double half_abs_troi_two = half_sign_troi_two * troi_two;
/*
* Tre:
*/
const double half_abs_prem_tre = half_sign_prem_tre * prem_tre;
const double sign_tre_two_horizo = half_sign_prem_tre + half_sign_deux_tre;
const double half_abs_deux_tre = half_sign_deux_tre * deux_tre;
const double sign_tre_thr_horizo = half_sign_deux_tre + half_sign_troi_tre;
const double half_abs_troi_tre = half_sign_troi_tre * troi_tre;
const double sign_tre_fou_horizo = half_sign_troi_tre + half_sign_quat_tre;
const double half_abs_quat_tre = half_sign_quat_tre * quat_tre;
/*
* Thr:
*/
const double half_abs_prem_thr = half_sign_prem_thr * prem_thr;
const double sign_dos_thr_vertic = half_sign_prem_thr + half_sign_deux_thr;
const double half_abs_deux_thr = half_sign_deux_thr * deux_thr;
const double sign_tre_thr_vertic = half_sign_deux_thr + half_sign_troi_thr;
const double half_abs_troi_thr = half_sign_troi_thr * troi_thr;
const double sign_qua_thr_vertic = half_sign_troi_thr + half_sign_quat_thr;
const double half_abs_quat_thr = half_sign_quat_thr * quat_thr;
/*
* Qua:
*/
const double half_abs_deux_qua = half_sign_deux_qua * deux_qua;
const double sign_qua_thr_horizo = half_sign_deux_qua + half_sign_troi_qua;
const double half_abs_troi_qua = half_sign_troi_qua * troi_qua;
const double sign_qua_fou_horizo = half_sign_troi_qua + half_sign_quat_qua;
const double half_abs_quat_qua = half_sign_quat_qua * quat_qua;
/*
* Fou:
*/
const double half_abs_deux_fou = half_sign_deux_fou * deux_fou;
const double sign_tre_fou_vertic = half_sign_deux_fou + half_sign_troi_fou;
const double half_abs_troi_fou = half_sign_troi_fou * troi_fou;
const double sign_qua_fou_vertic = half_sign_troi_fou + half_sign_quat_fou;
const double half_abs_quat_fou = half_sign_quat_fou * quat_fou;
/*
* Useful later:
*/
const double tre_thr_minus_dos_two = deux_thr + deux_dos;
/*
* Dos:
*/
const double half_size_dos_two_horizo =
FAST_MIN( half_abs_prem_dos, half_abs_deux_dos );
const double half_size_dos_thr_horizo =
FAST_MIN( half_abs_troi_dos, half_abs_deux_dos );
/*
* Two:
*/
const double half_size_dos_two_vertic =
FAST_MIN( half_abs_prem_two, half_abs_deux_two );
const double half_size_tre_two_vertic =
FAST_MIN( half_abs_troi_two, half_abs_deux_two );
/*
* Tre:
*/
const double half_size_tre_two_horizo =
FAST_MIN( half_abs_prem_tre, half_abs_deux_tre );
const double half_size_tre_thr_horizo =
FAST_MIN( half_abs_deux_tre, half_abs_troi_tre );
const double half_size_tre_fou_horizo =
FAST_MIN( half_abs_quat_tre, half_abs_troi_tre );
FAST_MIN( half_abs_troi_tre, half_abs_deux_tre );
/*
* Thr:
*/
const double half_size_dos_thr_vertic =
FAST_MIN( half_abs_prem_thr, half_abs_deux_thr );
const double half_size_tre_thr_vertic =
FAST_MIN( half_abs_deux_thr, half_abs_troi_thr );
const double half_size_qua_thr_vertic =
FAST_MIN( half_abs_quat_thr, half_abs_troi_thr );
/*
* Qua:
*/
const double half_size_qua_thr_horizo =
FAST_MIN( half_abs_deux_qua, half_abs_troi_qua );
const double half_size_qua_fou_horizo =
FAST_MIN( half_abs_quat_qua, half_abs_troi_qua );
/*
* Fou:
*/
const double half_size_tre_fou_vertic =
FAST_MIN( half_abs_deux_fou, half_abs_troi_fou );
const double half_size_qua_fou_vertic =
FAST_MIN( half_abs_quat_fou, half_abs_troi_fou );
FAST_MIN( half_abs_troi_thr, half_abs_deux_thr );
/*
* Compute the needed "right" (at the boundary between two input
* Compute the needed "right" (at the boundary between one input
* pixel areas) double resolution pixel value:
*/
/*
* Tre:
*/
const double two_times_tre_thrfou =
tre_thr_plus_tre_fou
const double two_times_dos_twothr =
dos_two_plus_dos_thr
+
sign_tre_thr_horizo * half_size_tre_thr_horizo
sign_dos_two_horizo * half_size_dos_two_horizo
-
sign_tre_fou_horizo * half_size_tre_fou_horizo;
sign_dos_thr_horizo * half_size_dos_thr_horizo;
/*
* Compute the needed "down" double resolution pixel value:
*/
/*
* Thr:
*/
const double two_times_trequa_thr =
tre_thr_plus_qua_thr
const double two_times_dostre_two =
dos_two_plus_tre_two
+
sign_tre_thr_vertic * half_size_tre_thr_vertic
sign_dos_two_vertic * half_size_dos_two_vertic
-
sign_qua_thr_vertic * half_size_qua_thr_vertic;
sign_tre_two_vertic * half_size_tre_two_vertic;
/*
* Compute the "diagonal" (at the boundary between four input
* Compute the "diagonal" (at the boundary between thrr input
* pixel areas) double resolution pixel value:
*/
const double four_times_trequa_thrfou =
qua_fou_minus_tre_thr
const double four_times_dostre_twothr =
tre_thr_minus_dos_two
+
sign_qua_thr_horizo * half_size_qua_thr_horizo
sign_tre_two_horizo * half_size_tre_two_horizo
-
sign_qua_fou_horizo * half_size_qua_fou_horizo
sign_tre_thr_horizo * half_size_tre_thr_horizo
+
sign_tre_fou_vertic * half_size_tre_fou_vertic
sign_dos_thr_vertic * half_size_dos_thr_vertic
-
sign_qua_fou_vertic * half_size_qua_fou_vertic
sign_tre_thr_vertic * half_size_tre_thr_vertic
+
two_times_tre_thrfou
two_times_dos_twothr
+
two_times_trequa_thr;
two_times_dostre_two;
/* End of copy-paste from Nicolas' source.
/*
* Return the newly computed double density values:
*/
*r1 = two_times_tre_thrfou;
*r2 = two_times_trequa_thr;
*r3 = four_times_trequa_thrfou;
*r1 = two_times_dos_twothr;
*r2 = two_times_dostre_two;
*r3 = four_times_dostre_twothr;
}
/* Call nohalo_sharp_level_1 with an interpolator as a parameter.
@ -544,86 +515,77 @@ nohalo_sharp_level_1(
const double relative_y ) \
{ \
T* restrict out = (T *) pout; \
const T* restrict in = (T *) pin; \
\
const int relative_x_is_left = ( relative_x < 0. ); \
const int relative_y_is___up = ( relative_y < 0. ); \
const int relative_x_is_rite = ( relative_x >= 0. ); \
const int relative_y_is_down = ( relative_y >= 0. ); \
\
const int sign_of_relative_x = 2 * relative_x_is_rite - 1; \
const int sign_of_relative_y = 2 * relative_y_is_down - 1; \
\
const int corner_reflection_shift = \
( -2 + 4 * relative_x_is_left ) * bands \
+ \
( -2 + 4 * relative_y_is___up ) * lskip; \
relative_x_is_rite * bands + relative_y_is_down * lskip; \
\
const int sign_of_relative_x = 1 - 2 * relative_x_is_left; \
const int sign_of_relative_y = 1 - 2 * relative_y_is___up; \
\
const double x = ( 2 * sign_of_relative_x ) * relative_x; \
const double y = ( 2 * sign_of_relative_y ) * relative_y; \
\
const double x_times_y = x * y; \
const double w_times_y = y - x_times_y; \
const double x_times_z = x - x_times_y; \
const double w_times_z = 1. - x - w_times_y; \
\
const double x_times_y_over_4 = .25 * x_times_y; \
const double w_times_y_over_2 = .5 * w_times_y; \
const double x_times_z_over_2 = .5 * x_times_z; \
const T* restrict in = ( (T *) pin ) + corner_reflection_shift; \
\
const int shift_1_pixel = sign_of_relative_x * bands; \
const int shift_1_row = sign_of_relative_y * lskip; \
\
const int b1 = shift_1_pixel + corner_reflection_shift; \
const int b2 = 2 * shift_1_pixel + corner_reflection_shift; \
const int b3 = 3 * shift_1_pixel + corner_reflection_shift; \
const int b4 = 4 * shift_1_pixel + corner_reflection_shift; \
const double w = ( 2 * sign_of_relative_x ) * relative_x; \
const double z = ( 2 * sign_of_relative_y ) * relative_y; \
\
const int l1 = shift_1_row; \
const int l2 = 2 * shift_1_row; \
const int l3 = 3 * shift_1_row; \
const int l4 = 4 * shift_1_row; \
const int uno_two_shift = shift_1_row; \
const int uno_thr_shift = shift_1_row - shift_1_pixel; \
\
for( int z = 0; z < bands; z++ ) { \
const T dos_thr = in[b2 + l1]; \
const T dos_fou = in[b3 + l1]; \
const int dos_one_shift = shift_1_pixel; \
const int dos_two_shift = 0; \
const int dos_thr_shift = -shift_1_pixel; \
const int dos_fou_shift = -2 * shift_1_pixel; \
\
const T tre_two = in[b1 + l2]; \
const T tre_thr = in[b2 + l2]; \
const T tre_fou = in[b3 + l2]; \
const T tre_fiv = in[b4 + l2]; \
const int tre_one_shift = dos_one_shift - shift_1_row; \
const int tre_two_shift = -shift_1_row; \
const int tre_thr_shift = dos_thr_shift - shift_1_row; \
const int tre_fou_shift = dos_fou_shift - shift_1_row; \
\
const T qua_two = in[b1 + l3]; \
const T qua_thr = in[b2 + l3]; \
const T qua_fou = in[b3 + l3]; \
const T qua_fiv = in[b4 + l3]; \
const int qua_two_shift = tre_two_shift - shift_1_row; \
const int qua_thr_shift = tre_thr_shift - shift_1_row; \
\
const T cin_thr = in[b2 + l4]; \
const T cin_fou = in[b3 + l4]; \
const double x = 1. - w; \
const double w_times_z = w * z; \
const double x_times_z = x * z; \
const double w_times_y_over_2 = .5 * ( w - w_times_z ); \
const double x_times_z_over_2 = .5 * x_times_z; \
const double x_times_y_over_4 = .25 * ( x - x_times_z ); \
\
double two_times_tre_thrfou; \
double two_times_trequa_thr; \
double four_times_trequa_thrfou; \
for( int band = 0; band < bands; band++ ) { \
double two_times_dos_twothr; \
double two_times_dostre_two; \
double four_times_dostre_twothr; \
\
nohalo_sharp_level_1( dos_thr, dos_fou, \
tre_two, tre_thr, tre_fou, tre_fiv, \
qua_two, qua_thr, qua_fou, qua_fiv, \
cin_thr, cin_fou, \
&two_times_tre_thrfou, \
&two_times_trequa_thr, \
&four_times_trequa_thrfou ); \
const double dos_two = in[dos_two_shift]; \
\
nohalo_sharp_level_1( in[uno_two_shift], in[uno_thr_shift], \
in[dos_one_shift], dos_two, \
in[dos_thr_shift], in[dos_fou_shift], \
in[tre_one_shift], in[tre_two_shift], \
in[tre_thr_shift], in[tre_fou_shift], \
in[qua_two_shift], in[qua_thr_shift], \
&two_times_dos_twothr, \
&two_times_dostre_two, \
&four_times_dostre_twothr ); \
\
in += 1; \
\
const T result = bilinear_ ## inter<T>( \
w_times_z, \
x_times_z_over_2, \
w_times_y_over_2, \
x_times_y_over_4, \
tre_thr, \
two_times_tre_thrfou, \
two_times_trequa_thr, \
four_times_trequa_thrfou ); \
dos_two, \
two_times_dos_twothr, \
two_times_dostre_two, \
four_times_dostre_twothr ); \
\
out[z] = result; \
\
in += 1; \
out[band] = result; \
} \
}
@ -648,34 +610,35 @@ vips_interpolate_nohalo_interpolate( VipsInterpolate *interpolate,
/*
* floor's surrogate FAST_PSEUDO_FLOOR is used to make sure that the
* transition through 0 is smooth. If it is known that absolute_x
* and absolute_y will never be less than -.5, plain cast---that is,
* const int ix = absolute_x + .5---should be used instead. Any
* function which agrees with floor for non-integer values, and
* and absolute_y will never be less than 0, plain cast---that is,
* const int ix = absolute_x---should be used instead. Actually,
* any function which agrees with floor for non-integer values, and
* picks one of the two possibilities for integer values, can be
* used.
* used. FAST_PSEUDO_FLOOR fits the bill.
*/
const int ix = FAST_PSEUDO_FLOOR (absolute_x + 0.5);
const int iy = FAST_PSEUDO_FLOOR (absolute_y + 0.5);
const int ix = FAST_PSEUDO_FLOOR (absolute_x);
const int iy = FAST_PSEUDO_FLOOR (absolute_y);
/* Move the pointer to (the first band of) the central
pixel of the extended 5x5 stencil (tre_thr):
/*
* Move the pointer to (the first band of) the top/left pixel
* of the 2x2 group of pixel centers which contains the
* sampling location in its convex hull:
*/
const PEL * restrict p =
(PEL *) IM_REGION_ADDR( in, ix, iy );
const PEL * restrict p = (PEL *) IM_REGION_ADDR( in, ix, iy );
/* VIPS versions of Nicolas's pixel addressing values.
/*
* VIPS versions of Nicolas's pixel addressing values:
*/
const int bands = in->im->Bands;
const int lskip =
IM_REGION_LSKIP( in ) / IM_IMAGE_SIZEOF_ELEMENT( in->im );
const int lskip = IM_REGION_LSKIP( in ) / IM_IMAGE_SIZEOF_ELEMENT( in->im );
/*
* x is the x-coordinate of the sampling point relative to the
* position of the tre_thr pixel center. Similarly for y. Range of
* values: (-.5,.5].
* position of the center of the convex hull of the 2x2 block of
* closest pixels. Similarly for y. Range of values: [-.5,.5).
*/
const double relative_x = absolute_x - ix;
const double relative_y = absolute_y - iy;
const double relative_x = absolute_x - ix - .5;
const double relative_y = absolute_y - iy - .5;
#define CALL( T, inter ) \
nohalo_sharp_level_1_ ## inter<T>( out, \
@ -750,11 +713,11 @@ vips_interpolate_nohalo_class_init( VipsInterpolateNohaloClass *klass )
VIPS_INTERPOLATE_CLASS( klass );
object_class->nickname = "nohalo";
object_class->description = _( "Bilinear plus edge enhance" );
object_class->description = _( "Edge-enhancing bilinear" );
interpolate_class->interpolate =
vips_interpolate_nohalo_interpolate;
interpolate_class->window_size = 5;
interpolate_class->window_size = 4;
}
static void