diff --git a/MagickCore/quantize.c b/MagickCore/quantize.c
index 09b8e48..c141df0 100644
--- a/MagickCore/quantize.c
+++ b/MagickCore/quantize.c
@@ -543,8 +543,7 @@
       image_view=AcquireAuthenticCacheView(image,exception);
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
       #pragma omp parallel for schedule(static,4) shared(status) \
-        if ((image->rows*image->columns) > 8192) \
-          num_threads(GetMagickResourceLimit(ThreadResource))
+        IsConcurrentDos(image->columns,image->rows,64)
 #endif
       for (y=0; y < (ssize_t) image->rows; y++)
       {
@@ -2381,8 +2380,7 @@
   if (image->storage_class == PseudoClass)
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
     #pragma omp parallel for schedule(static,4) shared(progress,status) \
-      if (image->colors > 256) \
-        num_threads(GetMagickResourceLimit(ThreadResource))
+      IsConcurrentUno(image->colors,256)
 #endif
     for (i=0; i < (ssize_t) image->colors; i++)
     {
@@ -2410,8 +2408,7 @@
   image_view=AcquireAuthenticCacheView(image,exception);
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
   #pragma omp parallel for schedule(static,4) shared(progress,status) \
-    if ((image->rows*image->columns) > 8192) \
-      num_threads(GetMagickResourceLimit(ThreadResource))
+    IsConcurrentDos(image->columns,image->rows,64)
 #endif
   for (y=0; y < (ssize_t) image->rows; y++)
   {
@@ -3308,8 +3305,7 @@
       image_view=AcquireAuthenticCacheView(image,exception);
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
       #pragma omp parallel for schedule(static,4) shared(status) \
-        if ((image->rows*image->columns) > 8192) \
-          num_threads(GetMagickResourceLimit(ThreadResource))
+        IsConcurrentDos(image->columns,image->rows,64)
 #endif
       for (y=0; y < (ssize_t) image->rows; y++)
       {
@@ -3387,8 +3383,7 @@
   image_view=AcquireAuthenticCacheView(image,exception);
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
   #pragma omp parallel for schedule(static,4) shared(status) \
-    if ((image->rows*image->columns) > 8192) \
-      num_threads(GetMagickResourceLimit(ThreadResource))
+    IsConcurrentDos(image->columns,image->rows,64)
 #endif
   for (y=0; y < (ssize_t) image->rows; y++)
   {