| /* lbb (locally bounded bicubic) resampler |
| * |
| * N. Robidoux, C. Racette and J. Cupitt, 23-28/03/2010 |
| * |
| * N. Robidoux, 16-19/05/2010 |
| */ |
| |
| /* |
| |
| 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. |
| |
| 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. |
| |
| 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 |
| |
| */ |
| |
| /* |
| |
| These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk |
| |
| */ |
| |
| /* |
| * 2010 (c) Nicolas Robidoux, Chantal Racette, John Cupitt. |
| * |
| * Nicolas Robidoux thanks Adam Turcotte, Geert Jordaens, Ralf Meyer, |
| * Øyvind Kolås, Minglun Gong, Eric Daoust and Sven Neumann for useful |
| * comments and code. |
| * |
| * Chantal Racette's image resampling research and programming funded |
| * in part by a NSERC Discovery Grant awarded to Julien Dompierre |
| * (20-61098). |
| */ |
| |
| /* |
| * LBB has two versions: |
| * |
| * A "soft" version, which shows a little less staircasing and a |
| * little more haloing, and which is a little more expensive to |
| * compute. We recommend this as the default. |
| * |
| * A "sharp" version, which shows a little more staircasing and a |
| * little less haloing, which is a little cheaper (it uses 6 less |
| * comparisons and 12 less "? :"), and which appears to lead to less |
| * "zebra striping" when two diagonal interfaces are close to each |
| * other. |
| * |
| * The only difference between the two is that the "soft" versions |
| * uses local minima and maxima computed over 3x3 square blocks, and |
| * the "sharp" version uses local minima and maxima computed over 3x3 |
| * crosses. |
| * |
| * If you want to use the "soft" (more expensive) version, comment out |
| * the following three pre-processor code lines: |
| */ |
| #ifndef __LBB_CHEAP_H__ |
| #define __LBB_CHEAP_H__ |
| #endif |
| |
| /* |
| * LBB (Locally Bounded Bicubic) is a high quality nonlinear variant |
| * of Catmull-Rom. Images resampled with LBB have much smaller halos |
| * than images resampled with windowed sincs or other interpolatory |
| * cubic spline filters. Specifically, LBB halos are narrower and the |
| * over/undershoot amplitude is smaller. This is accomplished without |
| * significantly affecting the smoothness of the result (compared to |
| * Catmull-Rom). |
| * |
| * Another important property is that the resampled values are |
| * contained within the range of nearby input values. Consequently, no |
| * final clamping is needed to stay "in range" (e.g., 0-255 for |
| * standard 8-bit images). |
| * |
| * LBB was developed by Nicolas Robidoux and Chantal Racette of the |
| * Department of Mathematics and Computer Science of Laurentian |
| * University in the course of C. Racette's Masters thesis in |
| * Computational Sciences. Preliminary work directly leading to the |
| * LBB method and code was performed by C. Racette and N. Robidoux in |
| * 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, |
| * one convex hull of four nearby input points at a time, using four |
| * point values, four x-derivatives, four y-derivatives, and four |
| * cross-derivatives. |
| * |
| * --The stencil for values in a square patch is the usual 4x4. |
| * |
| * --LBB is interpolatory. |
| * |
| * --It is C^1 with continuous cross derivatives. |
| * |
| * --When the limiters are inactive, LBB gives the same result as |
| * Catmull-Rom. |
| * |
| * --When used on binary images, LBB gives results similar to bicubic |
| * Hermite with all first derivatives---but not necessarily the |
| * cross derivatives (this last assertion needs to be double |
| * checked)--at input pixel locations set to zero. |
| * |
| * --The LBB reconstruction is locally bounded: Over each square |
| * patch, the surface is contained between the minimum and the |
| * maximum of the 16 nearest input pixel values. |
| * |
| * --Consequently, the LBB reconstruction is globally bounded between |
| * the very smallest input pixel value and the very largest input |
| * pixel value. It is not necessary to clamp results. |
| * |
| * The LBB method is based on the method of Ken Brodlie, Petros |
| * Mashwama and Sohail Butt for constraining Hermite interpolants |
| * between globally defined planes: |
| * |
| * Visualization of surface data to preserve positivity and other |
| * simple constraints. Computer & Graphics, Vol. 19, Number 4, pages |
| * 585-594, 1995. DOI: 10.1016/0097-8493(95)00036-C. |
| * |
| * Instead of forcing the reconstructed surface to lie between two |
| * GLOBALLY defined planes, LBB constrains one patch at a time to lie |
| * between LOCALLY defined planes. This is accomplished by |
| * constraining the derivatives (x, y and cross) at each input pixel |
| * location so that if the constraint was applied everywhere the |
| * surface would fit between the min and max of the values at the 9 |
| * closest pixel locations. Because this is done with each of the four |
| * pixel locations which define the bicubic patch, this forces the |
| * reconstructed surface to lie between the min and max of the values |
| * at the 16 closest values pixel locations. (Each corner defines its |
| * own 3x3 subgroup of the 4x4 stencil. Consequently, the surface is |
| * necessarily above the minimum of the four minima, which happens to |
| * be the minimum over the 4x4. Similarly with the maxima.) |
| * |
| * The above paragraph described the "soft" version of LBB. The |
| * "sharp" version is similar. |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif /*HAVE_CONFIG_H*/ |
| #include <vips/intl.h> |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #include <vips/vips.h> |
| #include <vips/internal.h> |
| |
| #include "templates.h" |
| |
| #define VIPS_TYPE_INTERPOLATE_LBB \ |
| (vips_interpolate_lbb_get_type()) |
| #define VIPS_INTERPOLATE_LBB( obj ) \ |
| (G_TYPE_CHECK_INSTANCE_CAST( (obj), \ |
| VIPS_TYPE_INTERPOLATE_LBB, VipsInterpolateLbb )) |
| #define VIPS_INTERPOLATE_LBB_CLASS( klass ) \ |
| (G_TYPE_CHECK_CLASS_CAST( (klass), \ |
| VIPS_TYPE_INTERPOLATE_LBB, VipsInterpolateLbbClass)) |
| #define VIPS_IS_INTERPOLATE_LBB( obj ) \ |
| (G_TYPE_CHECK_INSTANCE_TYPE( (obj), VIPS_TYPE_INTERPOLATE_LBB )) |
| #define VIPS_IS_INTERPOLATE_LBB_CLASS( klass ) \ |
| (G_TYPE_CHECK_CLASS_TYPE( (klass), VIPS_TYPE_INTERPOLATE_LBB )) |
| #define VIPS_INTERPOLATE_LBB_GET_CLASS( obj ) \ |
| (G_TYPE_INSTANCE_GET_CLASS( (obj), \ |
| VIPS_TYPE_INTERPOLATE_LBB, VipsInterpolateLbbClass )) |
| |
| typedef struct _VipsInterpolateLbb { |
| VipsInterpolate parent_object; |
| |
| } VipsInterpolateLbb; |
| |
| typedef struct _VipsInterpolateLbbClass { |
| VipsInterpolateClass parent_class; |
| |
| } VipsInterpolateLbbClass; |
| |
| #define LBB_ABS(x) ( ((x)>=0.) ? (x) : -(x) ) |
| #define LBB_SIGN(x) ( ((x)>=0.) ? 1.0 : -1.0 ) |
| /* |
| * MIN and MAX macros set up so that I can put the likely winner in |
| * the first argument (forward branch likely blah blah blah): |
| */ |
| #define LBB_MIN(x,y) ( ((x)<=(y)) ? (x) : (y) ) |
| #define LBB_MAX(x,y) ( ((x)>=(y)) ? (x) : (y) ) |
| |
| static inline double |
| lbbicubic( const double c00, |
| const double c10, |
| const double c01, |
| const double c11, |
| const double c00dx, |
| const double c10dx, |
| const double c01dx, |
| const double c11dx, |
| const double c00dy, |
| const double c10dy, |
| const double c01dy, |
| const double c11dy, |
| const double c00dxdy, |
| const double c10dxdy, |
| const double c01dxdy, |
| const double c11dxdy, |
| const double uno_one, |
| const double uno_two, |
| const double uno_thr, |
| const double uno_fou, |
| 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 qua_one, |
| const double qua_two, |
| const double qua_thr, |
| const double qua_fou ) |
| { |
| /* |
| * STENCIL (FOOTPRINT) OF INPUT VALUES: |
| * |
| * The stencil of LBB is the same as for any standard Hermite |
| * bicubic (e.g., Catmull-Rom): |
| * |
| * (ix-1,iy-1) (ix,iy-1) (ix+1,iy-1) (ix+2,iy-1) |
| * = uno_one = uno_two = uno_thr = uno_fou |
| * |
| * (ix-1,iy) (ix,iy) (ix+1,iy) (ix+2,iy) |
| * = dos_one = dos_two = dos_thr = dos_fou |
| * X |
| * (ix-1,iy+1) (ix,iy+1) (ix+1,iy+1) (ix+2,iy+1) |
| * = tre_one = tre_two = tre_thr = tre_fou |
| * |
| * (ix-1,iy+2) (ix,iy+2) (ix+1,iy+2) (ix+2,iy+2) |
| * = qua_one = qua_two = qua_thr = qua_fou |
| * |
| * where ix is the (pseudo-)floor of the requested left-to-right |
| * location ("X"), and iy is the floor of the requested up-to-down |
| * location. |
| */ |
| |
| #if defined (__LBB_CHEAP_H__) |
| /* |
| * Computation of the four min and four max over 3x3 input data |
| * sub-crosses of the 4x4 input stencil, performed with only 22 |
| * comparisons and 28 "? :". If you can figure out how to do this |
| * more efficiently, let us know. |
| */ |
| 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 m3 = (uno_two <= dos_one) ? uno_two : dos_one ; |
| const double M3 = (uno_two <= dos_one) ? dos_one : uno_two ; |
| const double m4 = (uno_thr <= dos_fou) ? uno_thr : dos_fou ; |
| const double M4 = (uno_thr <= dos_fou) ? dos_fou : uno_thr ; |
| const double m5 = (tre_one <= qua_two) ? tre_one : qua_two ; |
| const double M5 = (tre_one <= qua_two) ? qua_two : tre_one ; |
| const double m6 = (tre_fou <= qua_thr) ? tre_fou : qua_thr ; |
| const double M6 = (tre_fou <= qua_thr) ? qua_thr : tre_fou ; |
| const double m7 = LBB_MIN( m1, tre_two ); |
| const double M7 = LBB_MAX( M1, tre_two ); |
| const double m8 = LBB_MIN( m1, tre_thr ); |
| const double M8 = LBB_MAX( M1, tre_thr ); |
| const double m9 = LBB_MIN( m2, dos_two ); |
| const double M9 = LBB_MAX( M2, dos_two ); |
| const double m10 = LBB_MIN( m2, dos_thr ); |
| const double M10 = LBB_MAX( M2, dos_thr ); |
| const double min00 = LBB_MIN( m7, m3 ); |
| const double max00 = LBB_MAX( M7, M3 ); |
| const double min10 = LBB_MIN( m8, m4 ); |
| const double max10 = LBB_MAX( M8, M4 ); |
| const double min01 = LBB_MIN( m9, m5 ); |
| const double max01 = LBB_MAX( M9, M5 ); |
| const double min11 = LBB_MIN( m10, m6 ); |
| const double max11 = LBB_MAX( M10, M6 ); |
| #else |
| /* |
| * Computation of the four min and four max over 3x3 input data |
| * sub-blocks of the 4x4 input stencil, performed with only 28 |
| * comparisons and 34 "? :". If you can figure how to do this more |
| * efficiently, let us know. |
| */ |
| 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 ); |
| const double M11 = LBB_MAX( M6, qua_one ); |
| const double m12 = LBB_MIN( m7, uno_fou ); |
| 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 m8 = LBB_MIN( m5, m3 ); |
| const double M8 = LBB_MAX( M5, M3 ); |
| const double m9 = LBB_MIN( m5, m4 ); |
| const double M9 = LBB_MAX( M5, M4 ); |
| const double min00 = LBB_MIN( m8, m10 ); |
| const double max00 = LBB_MAX( M8, M10 ); |
| const double min10 = LBB_MIN( m8, m12 ); |
| const double max10 = LBB_MAX( M8, M12 ); |
| const double min01 = LBB_MIN( m9, m11 ); |
| const double max01 = LBB_MAX( M9, M11 ); |
| const double min11 = LBB_MIN( m9, m13 ); |
| const double max11 = LBB_MAX( M9, M13 ); |
| #endif |
| |
| /* |
| * The remainder of the "per channel" computation involves the |
| * computation of: |
| * |
| * --8 conditional moves, |
| * |
| * --8 signs (in which the sign of zero is unimportant), |
| * |
| * --12 minima of two values, |
| * |
| * --8 maxima of two values, |
| * |
| * --8 absolute values, |
| * |
| * for a grand total of 29 minima, 25 maxima, 8 conditional moves, 8 |
| * signs, and 8 absolute values. If everything is done with |
| * conditional moves, "only" 28+8+8+12+8+8=72 flags are involved |
| * (because initial min and max can be computed with one flag). |
| * |
| * The "per channel" part of the computation also involves 107 |
| * arithmetic operations (54 *, 21 +, 42 -). |
| */ |
| |
| /* |
| * Distances to the local min and max: |
| */ |
| const double u00 = dos_two - min00; |
| const double v00 = max00 - dos_two; |
| const double u10 = dos_thr - min10; |
| const double v10 = max10 - dos_thr; |
| const double u01 = tre_two - min01; |
| const double v01 = max01 - tre_two; |
| const double u11 = tre_thr - min11; |
| const double v11 = max11 - tre_thr; |
| |
| /* |
| * Initial values of the derivatives computed with centered |
| * differences. Factors of 1/2 are left out because they are folded |
| * in later: |
| */ |
| const double dble_dzdx00i = dos_thr - dos_one; |
| const double dble_dzdy11i = qua_thr - dos_thr; |
| const double dble_dzdx10i = dos_fou - dos_two; |
| const double dble_dzdy01i = qua_two - dos_two; |
| const double dble_dzdx01i = tre_thr - tre_one; |
| const double dble_dzdy10i = tre_thr - uno_thr; |
| const double dble_dzdx11i = tre_fou - tre_two; |
| const double dble_dzdy00i = tre_two - uno_two; |
| |
| /* |
| * Signs of the derivatives. The upcoming clamping does not change |
| * them (except if the clamping sends a negative derivative to 0, in |
| * which case the sign does not matter anyway). |
| */ |
| const double sign_dzdx00 = LBB_SIGN( dble_dzdx00i ); |
| const double sign_dzdx10 = LBB_SIGN( dble_dzdx10i ); |
| const double sign_dzdx01 = LBB_SIGN( dble_dzdx01i ); |
| const double sign_dzdx11 = LBB_SIGN( dble_dzdx11i ); |
| |
| const double sign_dzdy00 = LBB_SIGN( dble_dzdy00i ); |
| const double sign_dzdy10 = LBB_SIGN( dble_dzdy10i ); |
| const double sign_dzdy01 = LBB_SIGN( dble_dzdy01i ); |
| const double sign_dzdy11 = LBB_SIGN( dble_dzdy11i ); |
| |
| /* |
| * Initial values of the cross-derivatives. Factors of 1/4 are left |
| * out because folded in later: |
| */ |
| const double quad_d2zdxdy00i = uno_one - uno_thr + dble_dzdx01i; |
| const double quad_d2zdxdy10i = uno_two - uno_fou + dble_dzdx11i; |
| const double quad_d2zdxdy01i = qua_thr - qua_one - dble_dzdx00i; |
| const double quad_d2zdxdy11i = qua_fou - qua_two - dble_dzdx10i; |
| |
| /* |
| * Slope limiters. The key multiplier is 3 but we fold a factor of |
| * 2, hence 6: |
| */ |
| const double dble_slopelimit_00 = 6.0 * LBB_MIN( u00, v00 ); |
| const double dble_slopelimit_10 = 6.0 * LBB_MIN( u10, v10 ); |
| const double dble_slopelimit_01 = 6.0 * LBB_MIN( u01, v01 ); |
| const double dble_slopelimit_11 = 6.0 * LBB_MIN( u11, v11 ); |
| |
| /* |
| * Clamped first derivatives: |
| */ |
| const double dble_dzdx00 = |
| ( sign_dzdx00 * dble_dzdx00i <= dble_slopelimit_00 ) |
| ? dble_dzdx00i : sign_dzdx00 * dble_slopelimit_00; |
| const double dble_dzdy00 = |
| ( sign_dzdy00 * dble_dzdy00i <= dble_slopelimit_00 ) |
| ? dble_dzdy00i : sign_dzdy00 * dble_slopelimit_00; |
| const double dble_dzdx10 = |
| ( sign_dzdx10 * dble_dzdx10i <= dble_slopelimit_10 ) |
| ? dble_dzdx10i : sign_dzdx10 * dble_slopelimit_10; |
| const double dble_dzdy10 = |
| ( sign_dzdy10 * dble_dzdy10i <= dble_slopelimit_10 ) |
| ? dble_dzdy10i : sign_dzdy10 * dble_slopelimit_10; |
| const double dble_dzdx01 = |
| ( sign_dzdx01 * dble_dzdx01i <= dble_slopelimit_01 ) |
| ? dble_dzdx01i : sign_dzdx01 * dble_slopelimit_01; |
| const double dble_dzdy01 = |
| ( sign_dzdy01 * dble_dzdy01i <= dble_slopelimit_01 ) |
| ? dble_dzdy01i : sign_dzdy01 * dble_slopelimit_01; |
| const double dble_dzdx11 = |
| ( sign_dzdx11 * dble_dzdx11i <= dble_slopelimit_11 ) |
| ? dble_dzdx11i : sign_dzdx11 * dble_slopelimit_11; |
| const double dble_dzdy11 = |
| ( sign_dzdy11 * dble_dzdy11i <= dble_slopelimit_11 ) |
| ? dble_dzdy11i : sign_dzdy11 * dble_slopelimit_11; |
| |
| /* |
| * Sums and differences of first derivatives: |
| */ |
| const double twelve_sum00 = 6.0 * ( dble_dzdx00 + dble_dzdy00 ); |
| const double twelve_dif00 = 6.0 * ( dble_dzdx00 - dble_dzdy00 ); |
| const double twelve_sum10 = 6.0 * ( dble_dzdx10 + dble_dzdy10 ); |
| const double twelve_dif10 = 6.0 * ( dble_dzdx10 - dble_dzdy10 ); |
| const double twelve_sum01 = 6.0 * ( dble_dzdx01 + dble_dzdy01 ); |
| const double twelve_dif01 = 6.0 * ( dble_dzdx01 - dble_dzdy01 ); |
| const double twelve_sum11 = 6.0 * ( dble_dzdx11 + dble_dzdy11 ); |
| const double twelve_dif11 = 6.0 * ( dble_dzdx11 - dble_dzdy11 ); |
| |
| /* |
| * Absolute values of the sums: |
| */ |
| const double twelve_abs_sum00 = LBB_ABS( twelve_sum00 ); |
| const double twelve_abs_sum10 = LBB_ABS( twelve_sum10 ); |
| const double twelve_abs_sum01 = LBB_ABS( twelve_sum01 ); |
| const double twelve_abs_sum11 = LBB_ABS( twelve_sum11 ); |
| |
| /* |
| * Scaled distances to the min: |
| */ |
| const double u00_times_36 = 36.0 * u00; |
| const double u10_times_36 = 36.0 * u10; |
| const double u01_times_36 = 36.0 * u01; |
| const double u11_times_36 = 36.0 * u11; |
| |
| /* |
| * First cross-derivative limiter: |
| */ |
| const double first_limit00 = twelve_abs_sum00 - u00_times_36; |
| const double first_limit10 = twelve_abs_sum10 - u10_times_36; |
| const double first_limit01 = twelve_abs_sum01 - u01_times_36; |
| const double first_limit11 = twelve_abs_sum11 - u11_times_36; |
| |
| const double quad_d2zdxdy00ii = LBB_MAX( quad_d2zdxdy00i, first_limit00 ); |
| const double quad_d2zdxdy10ii = LBB_MAX( quad_d2zdxdy10i, first_limit10 ); |
| const double quad_d2zdxdy01ii = LBB_MAX( quad_d2zdxdy01i, first_limit01 ); |
| const double quad_d2zdxdy11ii = LBB_MAX( quad_d2zdxdy11i, first_limit11 ); |
| |
| /* |
| * Scaled distances to the max: |
| */ |
| const double v00_times_36 = 36.0 * v00; |
| const double v10_times_36 = 36.0 * v10; |
| const double v01_times_36 = 36.0 * v01; |
| const double v11_times_36 = 36.0 * v11; |
| |
| /* |
| * Second cross-derivative limiter: |
| */ |
| const double second_limit00 = v00_times_36 - twelve_abs_sum00; |
| const double second_limit10 = v10_times_36 - twelve_abs_sum10; |
| const double second_limit01 = v01_times_36 - twelve_abs_sum01; |
| const double second_limit11 = v11_times_36 - twelve_abs_sum11; |
| |
| const double quad_d2zdxdy00iii = LBB_MIN( quad_d2zdxdy00ii, second_limit00 ); |
| const double quad_d2zdxdy10iii = LBB_MIN( quad_d2zdxdy10ii, second_limit10 ); |
| const double quad_d2zdxdy01iii = LBB_MIN( quad_d2zdxdy01ii, second_limit01 ); |
| const double quad_d2zdxdy11iii = LBB_MIN( quad_d2zdxdy11ii, second_limit11 ); |
| |
| /* |
| * Absolute values of the differences: |
| */ |
| const double twelve_abs_dif00 = LBB_ABS( twelve_dif00 ); |
| const double twelve_abs_dif10 = LBB_ABS( twelve_dif10 ); |
| const double twelve_abs_dif01 = LBB_ABS( twelve_dif01 ); |
| const double twelve_abs_dif11 = LBB_ABS( twelve_dif11 ); |
| |
| /* |
| * Third cross-derivative limiter: |
| */ |
| const double third_limit00 = twelve_abs_dif00 - v00_times_36; |
| const double third_limit10 = twelve_abs_dif10 - v10_times_36; |
| const double third_limit01 = twelve_abs_dif01 - v01_times_36; |
| const double third_limit11 = twelve_abs_dif11 - v11_times_36; |
| |
| const double quad_d2zdxdy00iiii = LBB_MAX( quad_d2zdxdy00iii, third_limit00); |
| const double quad_d2zdxdy10iiii = LBB_MAX( quad_d2zdxdy10iii, third_limit10); |
| const double quad_d2zdxdy01iiii = LBB_MAX( quad_d2zdxdy01iii, third_limit01); |
| const double quad_d2zdxdy11iiii = LBB_MAX( quad_d2zdxdy11iii, third_limit11); |
| |
| /* |
| * Fourth cross-derivative limiter: |
| */ |
| const double fourth_limit00 = u00_times_36 - twelve_abs_dif00; |
| const double fourth_limit10 = u10_times_36 - twelve_abs_dif10; |
| const double fourth_limit01 = u01_times_36 - twelve_abs_dif01; |
| const double fourth_limit11 = u11_times_36 - twelve_abs_dif11; |
| |
| const double quad_d2zdxdy00 = LBB_MIN( quad_d2zdxdy00iiii, fourth_limit00); |
| const double quad_d2zdxdy10 = LBB_MIN( quad_d2zdxdy10iiii, fourth_limit10); |
| const double quad_d2zdxdy01 = LBB_MIN( quad_d2zdxdy01iiii, fourth_limit01); |
| const double quad_d2zdxdy11 = LBB_MIN( quad_d2zdxdy11iiii, fourth_limit11); |
| |
| /* |
| * Part of the result which does not need derivatives: |
| */ |
| 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; |
| |
| /* |
| * 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 newval = newval1 + .5 * newval2 + .25 * newval3; |
| |
| return newval; |
| } |
| |
| /* |
| * Call lbb with a type conversion operator as a parameter. |
| * |
| * It would be nice to do this with templates but we can't figure out |
| * how to do it cleanly. Suggestions welcome! |
| */ |
| #define LBB_CONVERSION( conversion ) \ |
| template <typename T> static void inline \ |
| lbb_ ## conversion( PEL* restrict pout, \ |
| const PEL* restrict pin, \ |
| const int bands, \ |
| const int lskip, \ |
| const double relative_x, \ |
| const double relative_y ) \ |
| { \ |
| T* restrict out = (T *) pout; \ |
| \ |
| const T* restrict in = (T *) pin; \ |
| \ |
| const int one_shift = -bands; \ |
| const int thr_shift = bands; \ |
| const int fou_shift = 2*bands; \ |
| \ |
| const int uno_two_shift = -lskip; \ |
| \ |
| const int tre_two_shift = lskip; \ |
| const int qua_two_shift = 2*lskip; \ |
| \ |
| const int uno_one_shift = uno_two_shift + one_shift; \ |
| const int dos_one_shift = one_shift; \ |
| const int tre_one_shift = tre_two_shift + one_shift; \ |
| const int qua_one_shift = qua_two_shift + one_shift; \ |
| \ |
| const int uno_thr_shift = uno_two_shift + thr_shift; \ |
| const int dos_thr_shift = thr_shift; \ |
| const int tre_thr_shift = tre_two_shift + thr_shift; \ |
| const int qua_thr_shift = qua_two_shift + thr_shift; \ |
| \ |
| const int uno_fou_shift = uno_two_shift + fou_shift; \ |
| const int dos_fou_shift = fou_shift; \ |
| const int tre_fou_shift = tre_two_shift + fou_shift; \ |
| const int qua_fou_shift = qua_two_shift + fou_shift; \ |
| \ |
| const double xp1over2 = relative_x; \ |
| const double xm1over2 = xp1over2 - 1.0; \ |
| const double onepx = 0.5 + xp1over2; \ |
| const double onemx = 1.5 - xp1over2; \ |
| const double xp1over2sq = xp1over2 * xp1over2; \ |
| \ |
| const double yp1over2 = relative_y; \ |
| const double ym1over2 = yp1over2 - 1.0; \ |
| const double onepy = 0.5 + yp1over2; \ |
| const double onemy = 1.5 - yp1over2; \ |
| const double yp1over2sq = yp1over2 * yp1over2; \ |
| \ |
| const double xm1over2sq = xm1over2 * xm1over2; \ |
| const double ym1over2sq = ym1over2 * ym1over2; \ |
| \ |
| const double twice1px = onepx + onepx; \ |
| const double twice1py = onepy + onepy; \ |
| const double twice1mx = onemx + onemx; \ |
| const double twice1my = onemy + onemy; \ |
| \ |
| const double xm1over2sq_times_ym1over2sq = xm1over2sq * ym1over2sq; \ |
| const double xp1over2sq_times_ym1over2sq = xp1over2sq * ym1over2sq; \ |
| const double xp1over2sq_times_yp1over2sq = xp1over2sq * yp1over2sq; \ |
| const double xm1over2sq_times_yp1over2sq = xm1over2sq * yp1over2sq; \ |
| \ |
| const double four_times_1px_times_1py = twice1px * twice1py; \ |
| const double four_times_1mx_times_1py = twice1mx * twice1py; \ |
| const double twice_xp1over2_times_1py = xp1over2 * twice1py; \ |
| const double twice_xm1over2_times_1py = xm1over2 * twice1py; \ |
| \ |
| const double twice_xm1over2_times_1my = xm1over2 * twice1my; \ |
| const double twice_xp1over2_times_1my = xp1over2 * twice1my; \ |
| const double four_times_1mx_times_1my = twice1mx * twice1my; \ |
| const double four_times_1px_times_1my = twice1px * twice1my; \ |
| \ |
| const double twice_1px_times_ym1over2 = twice1px * ym1over2; \ |
| const double twice_1mx_times_ym1over2 = twice1mx * ym1over2; \ |
| const double xp1over2_times_ym1over2 = xp1over2 * ym1over2; \ |
| const double xm1over2_times_ym1over2 = xm1over2 * ym1over2; \ |
| \ |
| const double xm1over2_times_yp1over2 = xm1over2 * yp1over2; \ |
| const double xp1over2_times_yp1over2 = xp1over2 * yp1over2; \ |
| const double twice_1mx_times_yp1over2 = twice1mx * yp1over2; \ |
| const double twice_1px_times_yp1over2 = twice1px * yp1over2; \ |
| \ |
| const double c00 = \ |
| four_times_1px_times_1py * xm1over2sq_times_ym1over2sq; \ |
| const double c00dx = \ |
| twice_xp1over2_times_1py * xm1over2sq_times_ym1over2sq; \ |
| const double c00dy = \ |
| twice_1px_times_yp1over2 * xm1over2sq_times_ym1over2sq; \ |
| const double c00dxdy = \ |
| xp1over2_times_yp1over2 * xm1over2sq_times_ym1over2sq; \ |
| \ |
| const double c10 = \ |
| four_times_1mx_times_1py * xp1over2sq_times_ym1over2sq; \ |
| const double c10dx = \ |
| twice_xm1over2_times_1py * xp1over2sq_times_ym1over2sq; \ |
| const double c10dy = \ |
| twice_1mx_times_yp1over2 * xp1over2sq_times_ym1over2sq; \ |
| const double c10dxdy = \ |
| xm1over2_times_yp1over2 * xp1over2sq_times_ym1over2sq; \ |
| \ |
| const double c01 = \ |
| four_times_1px_times_1my * xm1over2sq_times_yp1over2sq; \ |
| const double c01dx = \ |
| twice_xp1over2_times_1my * xm1over2sq_times_yp1over2sq; \ |
| const double c01dy = \ |
| twice_1px_times_ym1over2 * xm1over2sq_times_yp1over2sq; \ |
| const double c01dxdy = \ |
| xp1over2_times_ym1over2 * xm1over2sq_times_yp1over2sq; \ |
| \ |
| const double c11 = \ |
| four_times_1mx_times_1my * xp1over2sq_times_yp1over2sq; \ |
| const double c11dx = \ |
| twice_xm1over2_times_1my * xp1over2sq_times_yp1over2sq; \ |
| const double c11dy = \ |
| twice_1mx_times_ym1over2 * xp1over2sq_times_yp1over2sq; \ |
| const double c11dxdy = \ |
| xm1over2_times_ym1over2 * xp1over2sq_times_yp1over2sq; \ |
| \ |
| int band = bands; \ |
| \ |
| do \ |
| { \ |
| const double double_result = \ |
| lbbicubic( c00, \ |
| c10, \ |
| c01, \ |
| c11, \ |
| c00dx, \ |
| c10dx, \ |
| c01dx, \ |
| c11dx, \ |
| c00dy, \ |
| c10dy, \ |
| c01dy, \ |
| c11dy, \ |
| c00dxdy, \ |
| c10dxdy, \ |
| c01dxdy, \ |
| c11dxdy, \ |
| in[ uno_one_shift ], \ |
| in[ uno_two_shift ], \ |
| in[ uno_thr_shift ], \ |
| in[ uno_fou_shift ], \ |
| in[ dos_one_shift ], \ |
| in[ 0 ], \ |
| 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_one_shift ], \ |
| in[ qua_two_shift ], \ |
| in[ qua_thr_shift ], \ |
| in[ qua_fou_shift ] ); \ |
| \ |
| const T result = to_ ## conversion<T>( double_result ); \ |
| in++; \ |
| *out++ = result; \ |
| } while (--band); \ |
| } |
| |
| LBB_CONVERSION( fptypes ) |
| LBB_CONVERSION( withsign ) |
| LBB_CONVERSION( nosign ) |
| |
| #define CALL( T, conversion ) \ |
| lbb_ ## conversion<T>( out, \ |
| p, \ |
| bands, \ |
| lskip, \ |
| relative_x, \ |
| relative_y ); |
| |
| /* |
| * We need C linkage: |
| */ |
| extern "C" { |
| G_DEFINE_TYPE( VipsInterpolateLbb, vips_interpolate_lbb, |
| VIPS_TYPE_INTERPOLATE ); |
| } |
| |
| static void |
| vips_interpolate_lbb_interpolate( VipsInterpolate* restrict interpolate, |
| PEL* restrict out, |
| REGION* restrict in, |
| double absolute_x, |
| double absolute_y ) |
| { |
| /* |
| * 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 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. FAST_PSEUDO_FLOOR fits the bill. |
| * |
| * Then, x is the x-coordinate of the sampling point relative to the |
| * position of the top left corner of the convex hull of the 2x2 |
| * block of closest pixels. Similarly for y. Range of values: [0,1). |
| */ |
| 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 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 double relative_x = absolute_x - ix; |
| const double relative_y = absolute_y - iy; |
| |
| /* |
| * VIPS versions of Nicolas's pixel addressing values. |
| */ |
| const int actual_bands = in->im->Bands; |
| const int lskip = IM_REGION_LSKIP( in ) / IM_IMAGE_SIZEOF_ELEMENT( in->im ); |
| /* |
| * Double the bands for complex images to account for the real and |
| * imaginary parts being computed independently: |
| */ |
| const int bands = |
| vips_bandfmt_iscomplex( in->im->BandFmt ) ? 2 * actual_bands : actual_bands; |
| |
| switch( in->im->BandFmt ) { |
| case IM_BANDFMT_UCHAR: |
| CALL( unsigned char, nosign ); |
| break; |
| |
| case IM_BANDFMT_CHAR: |
| CALL( signed char, withsign ); |
| break; |
| |
| case IM_BANDFMT_USHORT: |
| CALL( unsigned short, nosign ); |
| break; |
| |
| case IM_BANDFMT_SHORT: |
| CALL( signed short, withsign ); |
| break; |
| |
| case IM_BANDFMT_UINT: |
| CALL( unsigned int, nosign ); |
| break; |
| |
| case IM_BANDFMT_INT: |
| CALL( signed int, withsign ); |
| break; |
| |
| /* |
| * Complex images are handled by doubling of bands. |
| */ |
| case IM_BANDFMT_FLOAT: |
| case IM_BANDFMT_COMPLEX: |
| CALL( float, fptypes ); |
| break; |
| |
| case IM_BANDFMT_DOUBLE: |
| case IM_BANDFMT_DPCOMPLEX: |
| CALL( double, fptypes ); |
| break; |
| |
| default: |
| g_assert( 0 ); |
| break; |
| } |
| } |
| |
| static void |
| vips_interpolate_lbb_class_init( VipsInterpolateLbbClass *klass ) |
| { |
| VipsObjectClass *object_class = VIPS_OBJECT_CLASS( klass ); |
| VipsInterpolateClass *interpolate_class = |
| VIPS_INTERPOLATE_CLASS( klass ); |
| |
| object_class->nickname = "lbb"; |
| object_class->description = _( "Reduced halo bicubic" ); |
| |
| interpolate_class->interpolate = vips_interpolate_lbb_interpolate; |
| interpolate_class->window_size = 4; |
| interpolate_class->window_offset = 2; |
| /* |
| * Note from nicolas: If things were sane, window_offset should be |
| * 1, not 2. |
| */ |
| } |
| |
| static void |
| vips_interpolate_lbb_init( VipsInterpolateLbb *lbb ) |
| { |
| } |
