Index: tiff-4.0.10/libtiff/tif_dirwrite.c =================================================================== --- tiff-4.0.10.orig/libtiff/tif_dirwrite.c 2018-06-24 22:26:30.335763566 +0200 +++ tiff-4.0.10/libtiff/tif_dirwrite.c 2018-11-19 14:21:42.703256410 +0100 @@ -1883,6 +1883,9 @@ TIFFWriteDirectoryTagTransferfunction(TI } m=(1<<tif->tif_dir.td_bitspersample); n=tif->tif_dir.td_samplesperpixel-tif->tif_dir.td_extrasamples; + if (tif->tif_dir.td_transferfunction[2] == NULL || + tif->tif_dir.td_transferfunction[1] == NULL) + n = 1; /* * Check if the table can be written as a single column, * or if it must be written as 3 columns. Note that we