deprecate im_contrast_surface()

slower than calling conv a few times

ChangeLog

@@ -10,6 +10,8 @@
 - vipsthumbnail allows non-square bounding boxes, thanks seth
 - add vips_matrixprint()
 - add @point subsample mode to vips_subsample()
+- im_contrast_surface() deprecated: it was slower than calling conv a few
+  times
 
 18/10/13	started 7.36.3
 - fix compiler warnings in ubuntu 13.10

TODO

@@ -1,4 +1,3 @@
-
 - do conv and morph quickly as simple wrappers over the vips7 operations
 
 - add vips_gaussian_blur() with approx / int / float precision, maybe

libvips/convolution/Makefile.am

@@ -12,7 +12,6 @@ libconvolution_la_SOURCES = \
 	im_aconvsep.c \
 	im_conv.c \
 	im_conv_f.c \
-	im_contrast_surface.c \
 	im_fastcor.c \
 	im_gradcor.c \
 	im_sharpen.c \

libvips/convolution/im_contrast_surface.c

@@ -1,263 +0,0 @@
-/* im_contrast_surface
- *
- * Copyright: 2006, The Nottingham Trent University
- *
- * Author: Tom Vajzovic
- * (based on algorithm by Nicos Dessipris & John Cupitt)
- *
- * Written on: 2006-03-13
- * 3/2/10
- * 	- gtkdoc
- * 	- small cleanups
- */
-
-/*
-
-    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., 51 Franklin Street, Fifth Floor, Boston, MA
-    02110-1301  USA
-
- */
-
-/*
-
-    These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
-
- */
-
-/** HEADERS **/
-
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif /*HAVE_CONFIG_H */
-
-#ifdef NOT_IN_VIPS
-#define _(s) (s)
-#else
-#include <vips/intl.h>
-#endif
-
-#include <stdlib.h>
-
-#include <vips/vips.h>
-#include <vips/region.h>
-
-/** MACROS **/
-
-/* from simple_macros.h */
-#define LESSER(a,b)  ((a)<(b)?(a):(b))
-#define DOUBLE(a)                ( (a)<<1 )
-#define DOUBLE_ADD_ONE(a)  ( 1 | ( (a)<<1 ) )
-
-/** LOCAL TYPES **/
-
-typedef struct cont_surf_params_s
-{
-  int half_win_size;
-  int spacing;
-
-} cont_surf_params_t;
-
-/** LOCAL FUNCTIONS DECLARATIONS **/
-
-int
-im_contrast_surface (IMAGE * in, IMAGE * out, int half_win_size, int spacing);
-
-int
-im_contrast_surface_raw (IMAGE * in, IMAGE * out, int half_win_size,
-			 int spacing);
-
-static int cont_surf_gen (REGION * to_make, void *seq, 
-			  void *a, void * b);
-
-static unsigned int calc_cont (REGION * reg, int win_size_less_one,
-			       int x_left, int y_top);
-
-/** EXPORTED FUNCTIONS **/
-
-/**
- * im_contrast_surface:
- * @in: input image
- * @out: output image
- * @half_win_size: window radius
- * @spacing: subsample output by this
- *
- * Generate an image where the value of each pixel represents the
- * contrast within a window of half_win_size from the corresponsing
- * point in the input image. Sub-sample by a factor of spacing.
- * 
- * See also: im_spcor(), im_gradcor().
- * 
- * Returns: 0 on success, -1 on error.
- */
-int
-im_contrast_surface (IMAGE * in, IMAGE * out, int half_win_size, int spacing)
-{
-  IMAGE *t1 = im_open_local (out, "im_contrast_surface intermediate", "p");
-
-  if (!t1
-      || im_embed (in, t1, 1, half_win_size, half_win_size,
-		   in->Xsize + DOUBLE (half_win_size),
-		   in->Ysize + DOUBLE (half_win_size))
-      || im_contrast_surface_raw (t1, out, half_win_size, spacing))
-
-    return -1;
-
-  out->Xoffset = 0;
-  out->Yoffset = 0;
-
-  return 0;
-}
-
-int
-im_contrast_surface_raw (IMAGE * in, IMAGE * out, int half_win_size,
-			 int spacing)
-{
-#define FUNCTION_NAME "im_contrast_surface_raw"
-
-  cont_surf_params_t *params;
-
-  if (im_piocheck (in, out) ||
-    im_check_uncoded (FUNCTION_NAME, in) ||
-    im_check_mono (FUNCTION_NAME, in) ||
-    im_check_format (FUNCTION_NAME, in, IM_BANDFMT_UCHAR))
-    return -1;
-
-  if (half_win_size < 1 || spacing < 1)
-    {
-      im_error (FUNCTION_NAME, "%s", _("bad parameters"));
-      return -1;
-    }
-
-  if (DOUBLE (half_win_size) >= LESSER (in->Xsize, in->Ysize))
-    {
-      im_error (FUNCTION_NAME,
-		"%s", _("parameters would result in zero size output image"));
-      return -1;
-    }
-
-  params = IM_NEW (out, cont_surf_params_t);
-
-  if (!params)
-    return -1;
-
-  params->half_win_size = half_win_size;
-  params->spacing = spacing;
-
-  if (im_cp_desc (out, in))
-    return -1;
-
-  out->BandFmt = IM_BANDFMT_UINT;
-
-  out->Xsize = 1 + ((in->Xsize - DOUBLE_ADD_ONE (half_win_size)) / spacing);
-  out->Ysize = 1 + ((in->Ysize - DOUBLE_ADD_ONE (half_win_size)) / spacing);
-
-  out->Xoffset = -half_win_size;
-  out->Yoffset = -half_win_size;
-
-  if (im_demand_hint (out, IM_FATSTRIP, in, NULL))
-    return -1;
-
-  return im_generate (out, im_start_one, cont_surf_gen, im_stop_one, in,
-		      params);
-
-#undef FUNCTION_NAME
-}
-
-/** LOCAL FUNCTIONS DEFINITIONS **/
-static int
-cont_surf_gen (REGION * to_make, void * seq, void *unrequired, void * b)
-{
-  /* I don't need *in, but I will recieve it anyway since im_start_one() needs it */
-
-  REGION * make_from = (REGION *) seq;
-  cont_surf_params_t * params = (cont_surf_params_t *) b;
-
-  unsigned int *row =
-    (unsigned int *) IM_REGION_ADDR (to_make, to_make->valid.left,
-				     to_make->valid.top);
-  int xoff;
-  int y;
-  int bottom = to_make->valid.top + to_make->valid.height;
-  size_t lskip = IM_REGION_LSKIP (to_make) / sizeof (unsigned int);
-
-  Rect area = {
-    params->spacing * to_make->valid.left,
-    params->spacing * to_make->valid.top,
-    DOUBLE_ADD_ONE (params->half_win_size) +
-      (params->spacing * (to_make->valid.width - 1)),
-    DOUBLE_ADD_ONE (params->half_win_size) +
-      (params->spacing * (to_make->valid.height - 1))
-  };
-
-  if (im_prepare (make_from, &area)
-      || !im_rect_equalsrect (&make_from->valid, &area))
-    return -1;
-
-  for (y = to_make->valid.top; y < bottom; ++y, row += lskip)
-
-    for (xoff = 0; xoff < to_make->valid.width; ++xoff)
-
-      row[xoff] =
-	calc_cont (make_from, DOUBLE (params->half_win_size),
-		   (xoff + to_make->valid.left) * params->spacing,
-		   y * params->spacing);
-
-  return 0;
-}
-
-static unsigned int
-calc_cont (REGION * reg, int win_size_less_one, int x_left, int y_top)
-{
-  unsigned char val;
-  unsigned char all_black = 1;
-  unsigned char *row;
-  unsigned int contrast = 0;
-  int xoff;
-  int yoff;
-  size_t lskip = IM_REGION_LSKIP (reg) / sizeof (unsigned char);
-
-  row = (unsigned char *) IM_REGION_ADDR (reg, x_left, y_top);
-  val = *row;
-
-  for (yoff = 0; yoff <= win_size_less_one && all_black; ++yoff, row += lskip)
-    for (xoff = 0; xoff <= win_size_less_one; ++xoff)
-      if (row[xoff] != val)
-	{
-	  all_black = 0;
-	  break;
-	}
-
-  if (all_black)
-    return contrast;
-
-  row = (unsigned char *) IM_REGION_ADDR (reg, x_left, y_top);
-
-  for (yoff = 0; yoff < win_size_less_one; ++yoff, row += lskip)
-    {
-      for (xoff = 0; xoff < win_size_less_one; ++xoff)
-	contrast +=
-	  abs (row[xoff + 1] - row[xoff]) + abs (row[xoff + lskip] -
-						 row[xoff]);
-
-      contrast += abs (row[xoff + lskip] - row[xoff]);
-    }
-
-  for (xoff = 0; xoff < win_size_less_one; ++xoff)
-    contrast += abs (row[xoff + 1] - row[xoff]);
-
-  return contrast;
-}

libvips/deprecated/vips7compat.c

@@ -2236,6 +2236,41 @@ im_addgnoise( IMAGE *in, IMAGE *out, double sigma )
 	return( 0 );
 }
 
+/* This replaces some custom code in 7.36 and earlier. The hand-made one was
+ * slower for spacing == 1, though faster for large values of spacing. 
+ *
+ * Not worth maintaining a special operator for. 
+ */
+int
+im_contrast_surface (IMAGE * in, IMAGE * out, int half_win_size, int spacing)
+{
+	VipsImage **t = (VipsImage **) 
+		vips_object_local_array( VIPS_OBJECT( out ), 10 );
+	int size = half_win_size * 2; 
+
+	int x, y;
+
+	t[0] = vips_image_new_matrixv( 1, 2, -1.0, 1.0 );
+	t[1] = vips_image_new_matrixv( 2, 1, -1.0, 1.0 );
+	t[8] = vips_image_new_matrix( size, size ); 
+
+	for( y = 0; y < size; y++ )
+		for( x = 0; x < size; x++ )
+			*VIPS_MATRIX( t[8], x, y ) = 1.0;
+
+	if( vips_conv( in, &t[2], t[0], NULL ) ||
+		vips_conv( in, &t[3], t[1], NULL ) ||
+		vips_abs( t[2], &t[4], NULL ) ||
+		vips_abs( t[3], &t[5], NULL ) ||
+		vips_add( t[4], t[5], &t[6], NULL ) ||
+		vips_conv( t[6], &t[7], t[8], NULL ) ||
+		vips_subsample( t[7], &t[9], spacing, spacing, NULL ) ||
+		vips_image_write( t[9], out ) )
+		return( -1 ); 
+
+	return( 0 );
+}
+
 static int
 vips__round( VipsImage *in, VipsImage *out, VipsOperationRound round )
 {

libvips/include/vips/convolution.h

@@ -94,8 +94,6 @@ int im_grad_y( VipsImage *in, VipsImage *out );
 int im_fastcor( VipsImage *in, VipsImage *ref, VipsImage *out );
 int im_spcor( VipsImage *in, VipsImage *ref, VipsImage *out );
 int im_gradcor( VipsImage *in, VipsImage *ref, VipsImage *out );
-int im_contrast_surface( VipsImage *in, VipsImage *out, 
-	int half_win_size, int spacing );
 
 #ifdef __cplusplus
 }

libvips/include/vips/vips7compat.h

@@ -918,6 +918,9 @@ int im_lindetect( VipsImage *in, VipsImage *out, INTMASK *mask );
 
 int im_addgnoise( VipsImage *in, VipsImage *out, double sigma );
 
+int im_contrast_surface( VipsImage *in, VipsImage *out, 
+	int half_win_size, int spacing );
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus*/