Rookie mistake, always sync the pixel cache
diff --git a/MagickCore/quantize.c b/MagickCore/quantize.c
index e96f7e5..a25d22d 100644
--- a/MagickCore/quantize.c
+++ b/MagickCore/quantize.c
@@ -2575,7 +2575,14 @@
SetPixelIndex(image,(Quantum) j,q);
q+=GetPixelChannels(image);
}
+ if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
+ {
+ status=MagickFalse;
+ break;
+ }
}
+ if (status == MagickFalse)
+ break;
/*
Calculate the new means (centroids) of the pixels in the new clusters.
*/