From 9b8a528e6cd0d30f4cde233b09ae22b9d108a441 Mon Sep 17 00:00:00 2001
From: anthony <anthony@git.imagemagick.org>
Date: Wed, 15 Sep 2010 07:48:39 +0000
Subject: [PATCH] Bug fix for handling filters with negative weights

---
 magick/resample.c | 18 ++++++++++--------
 magick/resize.c   |  4 ++--
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/magick/resample.c b/magick/resample.c
index 59dc1880b..4d77496a1 100644
--- a/magick/resample.c
+++ b/magick/resample.c
@@ -962,7 +962,7 @@ MagickExport MagickBooleanType ResamplePixelColor(
       case DitherVirtualPixelMethod:
       case HorizontalTileEdgeVirtualPixelMethod:
       case VerticalTileEdgeVirtualPixelMethod:
-        /* We need an average edge pixel, for the right edge!
+        /* We need an average edge pixel, from the correct edge!
            How should I calculate an average edge color?
            Just returning an averaged neighbourhood,
            works well in general, but falls down for TileEdge methods.
@@ -1122,10 +1122,15 @@ MagickExport MagickBooleanType ResamplePixelColor(
   /*
     Result sanity check -- this should NOT happen
   */
-  if ( hit < 4 || divisor_c < 1.0 ) {
+  if ( hit < 4 ) {
     /* not enough pixels in resampling, resort to direct interpolation */
+#if 0
+    pixel->opacity = pixel->red = pixel->green = pixel->blue = 0;
+    pixel->red = QuantumRange; /* show pixels for which EWA fails */
+#else
     status=InterpolateResampleFilter(resample_filter,
       resample_filter->interpolate,u0,v0,pixel);
+#endif
     return status;
   }
 
@@ -1437,11 +1442,8 @@ MagickExport void SetResampleFilter(ResampleFilter *resample_filter,
         resample_filter->support = (double)WLUT_WIDTH; /* not used yet */
 #endif
       for(Q=0; Q<WLUT_WIDTH; Q++)
-        //if ( (double) Q < resample_filter->support )
-          resample_filter->filter_lut[Q] = (double)
-               GetResizeFilterWeight(resize_filter,sqrt((double)Q)*r_scale);
-        //else
-        //  resample_filter->filter_lut[Q] = 0.0;
+        resample_filter->filter_lut[Q] = (double)
+             GetResizeFilterWeight(resize_filter,sqrt((double)Q)*r_scale);
       resize_filter = DestroyResizeFilter(resize_filter);
       break;
     }
@@ -1472,7 +1474,7 @@ MagickExport void SetResampleFilter(ResampleFilter *resample_filter,
 #endif
   }
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
-  if( GetOpenMPThreadId() == 0 )
+  /* if( GetOpenMPThreadId() == 0 ) */
 #endif
     if (GetImageArtifact(resample_filter->image,"resample:verbose")
           != (const char *) NULL)
diff --git a/magick/resize.c b/magick/resize.c
index 88e362807..1c4d95b0d 100644
--- a/magick/resize.c
+++ b/magick/resize.c
@@ -1043,7 +1043,7 @@ MagickExport ResizeFilter *AcquireResizeFilter(const Image *image,
     Expert Option Request for verbose details of the resulting filter
   */
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
-  if( GetOpenMPThreadId() == 0 ) {
+  /* if( GetOpenMPThreadId() == 0 ) { */
 #endif
     artifact=GetImageArtifact(image,"filter:verbose");
     if (artifact != (const char *) NULL)
@@ -1094,7 +1094,7 @@ MagickExport ResizeFilter *AcquireResizeFilter(const Image *image,
             GetMagickPrecision(), 0.0);
       }
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
-    }
+    /* } */
 #endif
   return(resize_filter);
 }
-- 
2.50.1