diff --git a/autotests/read/avif/profile_gray.avif b/autotests/read/avif/profile_gray.avif
new file mode 100644
index 0000000..23c3490
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diff --git a/autotests/read/avif/profile_gray.avif.json b/autotests/read/avif/profile_gray.avif.json
new file mode 100644
index 0000000..690827a
--- /dev/null
+++ b/autotests/read/avif/profile_gray.avif.json
@@ -0,0 +1,11 @@
+[
+    {
+        "fileName" : "profile_gray.png",
+        "colorSpace" : {
+            "colorModel" : "Gray",
+            "primaries" : "Custom",
+            "transferFunction" : "SRgb",
+            "gamma" : 2.31
+        }
+    }
+]
diff --git a/autotests/read/avif/profile_gray.png b/autotests/read/avif/profile_gray.png
new file mode 100644
index 0000000..d96b3d7
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diff --git a/autotests/read/avif/profile_gray_gamma22.avif b/autotests/read/avif/profile_gray_gamma22.avif
new file mode 100644
index 0000000..2d3fb21
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diff --git a/autotests/read/avif/profile_gray_gamma22.avif.json b/autotests/read/avif/profile_gray_gamma22.avif.json
new file mode 100644
index 0000000..3caa46e
--- /dev/null
+++ b/autotests/read/avif/profile_gray_gamma22.avif.json
@@ -0,0 +1,11 @@
+[
+    {
+        "fileName" : "profile_gray_gamma22.png",
+        "colorSpace" : {
+            "colorModel" : "Gray",
+            "primaries" : "Custom",
+            "transferFunction" : "Gamma",
+            "gamma" : 2.2
+        }
+    }
+]
diff --git a/autotests/read/avif/profile_gray_gamma22.png b/autotests/read/avif/profile_gray_gamma22.png
new file mode 100644
index 0000000..f9495bb
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diff --git a/autotests/read/avif/profile_gray_gamma28.avif b/autotests/read/avif/profile_gray_gamma28.avif
new file mode 100644
index 0000000..4debd2c
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diff --git a/autotests/read/avif/profile_gray_gamma28.avif.json b/autotests/read/avif/profile_gray_gamma28.avif.json
new file mode 100644
index 0000000..ffa07a4
--- /dev/null
+++ b/autotests/read/avif/profile_gray_gamma28.avif.json
@@ -0,0 +1,11 @@
+[
+    {
+        "fileName" : "profile_gray_gamma28.png",
+        "colorSpace" : {
+            "colorModel" : "Gray",
+            "primaries" : "Custom",
+            "transferFunction" : "Gamma",
+            "gamma" : 2.8
+        }
+    }
+]
diff --git a/autotests/read/avif/profile_gray_gamma28.png b/autotests/read/avif/profile_gray_gamma28.png
new file mode 100644
index 0000000..5b0fcd7
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diff --git a/autotests/read/avif/profile_gray_linear.avif b/autotests/read/avif/profile_gray_linear.avif
new file mode 100644
index 0000000..2e39010
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diff --git a/autotests/read/avif/profile_gray_linear.avif.json b/autotests/read/avif/profile_gray_linear.avif.json
new file mode 100644
index 0000000..931ca64
--- /dev/null
+++ b/autotests/read/avif/profile_gray_linear.avif.json
@@ -0,0 +1,11 @@
+[
+    {
+        "fileName" : "profile_gray_linear.png",
+        "colorSpace" : {
+            "colorModel" : "Gray",
+            "primaries" : "Custom",
+            "transferFunction" : "Linear",
+            "gamma" : 1
+        }
+    }
+]
diff --git a/autotests/read/avif/profile_gray_linear.png b/autotests/read/avif/profile_gray_linear.png
new file mode 100644
index 0000000..048be29
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diff --git a/autotests/read/avif/profile_gray_prophoto.avif b/autotests/read/avif/profile_gray_prophoto.avif
new file mode 100644
index 0000000..6160a10
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diff --git a/autotests/read/avif/profile_gray_prophoto.avif.json b/autotests/read/avif/profile_gray_prophoto.avif.json
new file mode 100644
index 0000000..7c5e532
--- /dev/null
+++ b/autotests/read/avif/profile_gray_prophoto.avif.json
@@ -0,0 +1,12 @@
+[
+    {
+        "fileName" : "profile_gray_prophoto.png",
+        "colorSpace" : {
+            "description" : "grayscale D50 with ProPhoto TRC",
+            "colorModel" : "Gray",
+            "primaries" : "Custom",
+            "transferFunction" : "Custom",
+            "gamma" : 0
+        }
+    }
+]
diff --git a/autotests/read/avif/profile_gray_prophoto.png b/autotests/read/avif/profile_gray_prophoto.png
new file mode 100644
index 0000000..77873fa
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