TIFF Group4 compression requires an image depth of 1

diff --git a/coders/tiff.c b/coders/tiff.c
index e2dfcee36c6c67e1ca45b3836ed4488231808524..8a854202cdd164d151664e15a0a3125e65e33855 100755 (executable)
--- a/coders/tiff.c
+++ b/coders/tiff.c
@@ -3194,6 +3194,7 @@ static MagickBooleanType WriteTIFFImage(const ImageInfo *image_info,
       case Group4Compression:
       {
         (void) SetImageType(image,BilevelType,exception);
+        (void) SetImageDepth(image,1,exception);
         break;
       }
       case JPEGCompression: