From 0957fd69eeb86ca9a4ca6801b7a87f37bd644d09 Mon Sep 17 00:00:00 2001
From: James Zern <jzern@google.com>
Date: Thu, 31 Mar 2022 21:38:00 -0700
Subject: [PATCH] tiffdec: add grayscale support

the file is always decoded to RGBA, so just the samples_per_px needed an
update

Bug: webp:563
Change-Id: I95d95c3b9e45dc8ecb2223f89f4ba791f0b21e8b
---
 imageio/tiffdec.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/imageio/tiffdec.c b/imageio/tiffdec.c
index 9c71bc65..d711fa4b 100644
--- a/imageio/tiffdec.c
+++ b/imageio/tiffdec.c
@@ -188,7 +188,9 @@ int ReadTIFF(const uint8_t* const data, size_t data_size,
     fprintf(stderr, "Error! Cannot retrieve TIFF samples-per-pixel info.\n");
     goto End;
   }
-  if (samples_per_px < 3 || samples_per_px > 4) goto End;  // not supported
+  if (!(samples_per_px == 1 || samples_per_px == 3 || samples_per_px == 4)) {
+    goto End;  // not supported
+  }
 
   if (!(TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &image_width) &&
         TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &image_height))) {