https://github.com/ImageMagick/ImageMagick/issues/1636

diff --git a/MagickCore/attribute.c b/MagickCore/attribute.c
index ae9f72f7506e1062ed40b64593e262befc215222..8c4c1984d17d8ab11b769959a86530bdc843984d 100644 (file)
--- a/MagickCore/attribute.c
+++ b/MagickCore/attribute.c
@@ -1492,6 +1492,7 @@ MagickExport MagickBooleanType SetImageType(Image *image,const ImageType type,
       quantize_info=AcquireQuantizeInfo(image_info);
       quantize_info->number_colors=2;
       quantize_info->colorspace=GRAYColorspace;
+      quantize_info->dither_method=NoDitherMethod;
       status=QuantizeImage(quantize_info,image,exception);
       quantize_info=DestroyQuantizeInfo(quantize_info);
       image->alpha_trait=UndefinedPixelTrait;

diff --git a/coders/pnm.c b/coders/pnm.c
index c6eb6342eb6e7aa8ba7c56bca7cec577e07a83cc..8b24e1d96592e08a0cb29ef70efff413c1c32dcd 100644 (file)
--- a/coders/pnm.c
+++ b/coders/pnm.c
@@ -604,7 +604,6 @@ static Image *ReadPNMImage(const ImageInfo *image_info,ExceptionInfo *exception)
         quantum_info=AcquireQuantumInfo(image_info,image);
         if (quantum_info == (QuantumInfo *) NULL)
           ThrowPNMException(ResourceLimitError,"MemoryAllocationFailed");
-        SetQuantumMinIsWhite(quantum_info,MagickTrue);
         extent=GetQuantumExtent(image,quantum_info,quantum_type);
         for (y=0; y < (ssize_t) image->rows; y++)
         {
@@ -1945,7 +1944,6 @@ static MagickBooleanType WritePNMImage(const ImageInfo *image_info,Image *image,
         if (quantum_info == (QuantumInfo *) NULL)
           ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
         (void) SetQuantumEndian(image,quantum_info,MSBEndian);
-        quantum_info->min_is_white=MagickFalse;
         pixels=GetQuantumPixels(quantum_info);
         for (y=0; y < (ssize_t) image->rows; y++)
         {
@@ -1988,7 +1986,6 @@ static MagickBooleanType WritePNMImage(const ImageInfo *image_info,Image *image,
         if (quantum_info == (QuantumInfo *) NULL)
           ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
         (void) SetQuantumEndian(image,quantum_info,MSBEndian);
-        quantum_info->min_is_white=MagickTrue;
         pixels=GetQuantumPixels(quantum_info);
         extent=GetQuantumExtent(image,quantum_info,GrayQuantum);
         for (y=0; y < (ssize_t) image->rows; y++)