diff --git a/src/libOpenImageIO/imagebufalgo_yee.cpp b/src/libOpenImageIO/imagebufalgo_yee.cpp
index 7ee875ebe5..25763dfdc8 100644
--- a/src/libOpenImageIO/imagebufalgo_yee.cpp
+++ b/src/libOpenImageIO/imagebufalgo_yee.cpp
@@ -52,7 +52,7 @@ class GaussianPyramid {
         if (lev >= PYRAMID_MAX_LEVELS)
             return 0.0f;
         else
-            return level[lev].getchannel(x, y, 0, 1);
+            return level[lev].getchannel(x, y, 0, 0);
     }
 
 #if 0 /* unused */
@@ -65,7 +65,7 @@ class GaussianPyramid {
     float operator()(int x, int y, int lev) const
     {
         OIIO_DASSERT(lev < PYRAMID_MAX_LEVELS);
-        return level[lev].getchannel(x, y, 0, 1);
+        return level[lev].getchannel(x, y, 0, 0);
     }
 #endif
 
diff --git a/testsuite/diff/ref/out-fmt6.txt b/testsuite/diff/ref/out-fmt6.txt
index e488da6520..1ddc33371e 100644
--- a/testsuite/diff/ref/out-fmt6.txt
+++ b/testsuite/diff/ref/out-fmt6.txt
@@ -16,7 +16,7 @@ Computing diff of "img1.exr" vs "img2.exr"
   121 pixels (2.95%) over 1e-06
 FAILURE
 Computing perceptual diff of "img1.exr" vs "img2.exr"
-  Max error  = 1.0 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
+  Max error  = 10.0 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
   121 pixels (2.95%) failed the perceptual test
 FAILURE
 Computing perceptual diff of "img1.exr" vs "img1.exr"
@@ -26,7 +26,7 @@ Comparing "img1.exr" and "img2.exr"
   Mean error = 0
   RMS error = 0
   Peak SNR = 0
-  Max error  = 1 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
+  Max error  = 10 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
   0 pixels (0%) over 0.008
   121 pixels (2.95%) over 0.004
   121 pixels (2.9541%) failed the perceptual test
@@ -38,7 +38,7 @@ Comparing "img1.exr" and "img2.exr"
   Mean error = 0
   RMS error = 0
   Peak SNR = 0
-  Max error  = 1 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
+  Max error  = 10 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
   0 pixels (0%) over 0.008
   121 pixels (2.95%) over 1.0
   121 pixels (2.9541%) failed the perceptual test
diff --git a/testsuite/diff/ref/out.txt b/testsuite/diff/ref/out.txt
index f5462e60c7..2000567703 100644
--- a/testsuite/diff/ref/out.txt
+++ b/testsuite/diff/ref/out.txt
@@ -16,7 +16,7 @@ Computing diff of "img1.exr" vs "img2.exr"
   121 pixels (2.95%) over 1e-06
 FAILURE
 Computing perceptual diff of "img1.exr" vs "img2.exr"
-  Max error  = 1 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
+  Max error  = 10 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
   121 pixels (2.95%) failed the perceptual test
 FAILURE
 Computing perceptual diff of "img1.exr" vs "img1.exr"
@@ -26,7 +26,7 @@ Comparing "img1.exr" and "img2.exr"
   Mean error = 0
   RMS error = 0
   Peak SNR = 0
-  Max error  = 1 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
+  Max error  = 10 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
   0 pixels (0%) over 0.008
   121 pixels (2.95%) over 0.004
   121 pixels (2.9541%) failed the perceptual test
@@ -38,7 +38,7 @@ Comparing "img1.exr" and "img2.exr"
   Mean error = 0
   RMS error = 0
   Peak SNR = 0
-  Max error  = 1 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
+  Max error  = 10 @ (5, 17, R)  values are 0.1, 0.1, 0.1 vs 0.1, 0.6, 0.1
   0 pixels (0%) over 0.008
   121 pixels (2.95%) over 1
   121 pixels (2.9541%) failed the perceptual test