diff --git a/testsuite/openexr-decreasingy/ref/out-alt.txt b/testsuite/openexr-decreasingy/ref/out-alt.txt
new file mode 100644
index 0000000000..2b3b12b12a
--- /dev/null
+++ b/testsuite/openexr-decreasingy/ref/out-alt.txt
@@ -0,0 +1,8 @@
+increasingY.exr      : 4080 x 3072, 3 channel, half openexr
+    SHA-1: F1BB46E882CB2F57C3E5E3546DA421BC65BE2856
+increasingY-copy.exr : 4080 x 3072, 3 channel, half openexr
+    SHA-1: F1BB46E882CB2F57C3E5E3546DA421BC65BE2856
+decreasingY.exr      : 4080 x 3072, 3 channel, half openexr
+    SHA-1: F1BB46E882CB2F57C3E5E3546DA421BC65BE2856
+decreasingY-copy.exr : 4080 x 3072, 3 channel, half openexr
+    SHA-1: F1BB46E882CB2F57C3E5E3546DA421BC65BE2856
diff --git a/testsuite/openexr-decreasingy/ref/out.txt b/testsuite/openexr-decreasingy/ref/out.txt
index 5e92b1164a..97e3d468aa 100644
--- a/testsuite/openexr-decreasingy/ref/out.txt
+++ b/testsuite/openexr-decreasingy/ref/out.txt
@@ -1,56 +1,8 @@
-Reading increasingY-resize.exr
-increasingY-resize.exr : 4080 x 3072, 3 channel, half openexr
-    channel list: R, G, B
-    compression: "zip"
-    Orientation: 1 (normal)
-    PixelAspectRatio: 1
-    ResolutionUnit: "in"
-    screenWindowCenter: 0, 0
-    screenWindowWidth: 1
-    XResolution: 72
-    YResolution: 72
-    oiio:subimages: 1
-    openexr:lineOrder: "increasingY"
-Reading increasingY-copy.exr
+increasingY.exr      : 4080 x 3072, 3 channel, half openexr
+    SHA-1: 55ECB0DBDCDA7AC0716E402DBB572E6EFAFBCBCB
 increasingY-copy.exr : 4080 x 3072, 3 channel, half openexr
-    channel list: R, G, B
-    compression: "zip"
-    Orientation: 1 (normal)
-    PixelAspectRatio: 1
-    ResolutionUnit: "in"
-    screenWindowCenter: 0, 0
-    screenWindowWidth: 1
-    XResolution: 72
-    YResolution: 72
-    oiio:subimages: 1
-    openexr:lineOrder: "increasingY"
-Reading decreasingY-resize.exr
-decreasingY-resize.exr : 4080 x 3072, 3 channel, half openexr
-    channel list: R, G, B
-    compression: "zip"
-    Orientation: 1 (normal)
-    PixelAspectRatio: 1
-    ResolutionUnit: "in"
-    screenWindowCenter: 0, 0
-    screenWindowWidth: 1
-    XResolution: 72
-    YResolution: 72
-    oiio:subimages: 1
-    openexr:lineOrder: "decreasingY"
-Reading decreasingY-copy.exr
+    SHA-1: 55ECB0DBDCDA7AC0716E402DBB572E6EFAFBCBCB
+decreasingY.exr      : 4080 x 3072, 3 channel, half openexr
+    SHA-1: 55ECB0DBDCDA7AC0716E402DBB572E6EFAFBCBCB
 decreasingY-copy.exr : 4080 x 3072, 3 channel, half openexr
-    channel list: R, G, B
-    compression: "zip"
-    Orientation: 1 (normal)
-    PixelAspectRatio: 1
-    ResolutionUnit: "in"
-    screenWindowCenter: 0, 0
-    screenWindowWidth: 1
-    XResolution: 72
-    YResolution: 72
-    oiio:subimages: 1
-    openexr:lineOrder: "decreasingY"
-Comparing "increasingY-copy.exr" and "decreasingY-copy.exr"
-PASS
-Comparing "increasingY-resize.exr" and "decreasingY-resize.exr"
-PASS
+    SHA-1: 55ECB0DBDCDA7AC0716E402DBB572E6EFAFBCBCB
diff --git a/testsuite/openexr-decreasingy/run.py b/testsuite/openexr-decreasingy/run.py
index db350c9319..d8b567ff20 100644
--- a/testsuite/openexr-decreasingy/run.py
+++ b/testsuite/openexr-decreasingy/run.py
@@ -14,31 +14,24 @@
 redirect = " >> out.txt 2>&1 "
 
 # Create reference images stored in increasingY order (default)
-# Resizing to a large image size to ensure scanline chunking logic is triggered.
-command += oiiotool("../common/tahoe-tiny.tif --resize 4080x3072 -o increasingY-resize.exr")
-command += info_command("increasingY-resize.exr", safematch=True, hash=False)
-command += oiiotool("increasingY-resize.exr -o increasingY-copy.exr")
-command += info_command("increasingY-copy.exr", safematch=True, hash=False)
+# Use a large image size to ensure scanline chunking logic is triggered.
+command += oiiotool("-pattern:type=half fill:topleft=1,0,0:topright=0,1,0:bottomleft=0,0,1:bottomright=1,1,1 4080x3072 3 -o increasingY.exr")
+command += info_command("increasingY.exr", safematch=True, hash=True, verbose=False)
+# Just do a straight copy of it via oiiotool, all default operations
+command += oiiotool("increasingY.exr -o increasingY-copy.exr")
+command += info_command("increasingY-copy.exr", safematch=True, hash=True, verbose=False)
 
-# Create an image in decreasing order via resizing (Tests ImageOutput::write_image() logic)
-command += oiiotool("../common/tahoe-tiny.tif --resize 4080x3072 --attrib openexr:lineOrder decreasingY -o decreasingY-resize.exr")
-command += info_command("decreasingY-resize.exr", safematch=True, hash=False)
+# Create an image in decreasing order (Tests ImageOutput::write_image() logic)
+command += oiiotool("-pattern:type=half fill:topleft=1,0,0:topright=0,1,0:bottomleft=0,0,1:bottomright=1,1,1 4080x3072 3 --attrib openexr:lineOrder decreasingY -o decreasingY.exr")
+command += info_command("decreasingY.exr", safematch=True, hash=True, verbose=False)
 
 # Create an image in decreasing order via copying a reference image. (Tests ImageBuf::write() logic)
-command += oiiotool("decreasingY-resize.exr --attrib openexr:lineOrder decreasingY -o decreasingY-copy.exr")
-command += info_command("decreasingY-copy.exr", safematch=True, hash=False)
+command += oiiotool("decreasingY.exr --attrib openexr:lineOrder decreasingY -o decreasingY-copy.exr")
+command += info_command("decreasingY-copy.exr", safematch=True, hash=True, verbose=False)
 
-# They should match
-command += diff_command("increasingY-copy.exr", "decreasingY-copy.exr")
-command += diff_command("increasingY-resize.exr", "decreasingY-resize.exr")
+# The hashes should all match!
 
 # Outputs to check against references.
-# This makes sure the images look the same since the line order is a storage detail and should not
-# change how the image actually looks. These comparisons help verify chunk order and scanlines are
-# processed properly.
 outputs = [
     "out.txt"
 ]
-
-
-#print "Running this command:\n" + command + "\n"