diff --git a/include/perm16.hpp b/include/perm16.hpp
index f4b3d92b..da65c158 100644
--- a/include/perm16.hpp
+++ b/include/perm16.hpp
@@ -73,7 +73,16 @@ struct alignas(16) PTransf16 : public Vect16 {
     }
 
     /** Returns a mask for the image of \c *this */
-    epu8 image_mask(bool complement = false) const;
+    epu8 image_mask_cmpestrm(bool complement = false) const;
+    /** Returns a mask for the image of \c *this */
+    epu8 image_mask_ref(bool complement = false) const;
+    epu8 image_mask(bool complement = false) const {
+#ifdef SIMDE_X86_SSE4_2_NATIVE
+      return image_mask_cmpestrm(complement);
+#else
+      return image_mask_ref(complement);
+#endif
+    }
     /** Returns a bit mask for the image of \c *this */
     uint32_t image_bitset(bool complement = false) const;
     /** Returns a mask for the domain of \c *this */
diff --git a/include/perm16_impl.hpp b/include/perm16_impl.hpp
index 6e6bde42..44ccf42b 100644
--- a/include/perm16_impl.hpp
+++ b/include/perm16_impl.hpp
@@ -57,13 +57,20 @@ inline PTransf16 PTransf16::right_one() const {
     return domain_mask(true) | epu8id;
 }
 
-inline epu8 PTransf16::image_mask(bool complement) const {
 #ifdef SIMDE_X86_SSE4_2_NATIVE
+inline epu8 PTransf16::image_mask_cmpestrm(bool complement) const {
     return complement ? _mm_cmpestrm(v, 16, one().v, 16, FIND_IN_VECT)
                       : _mm_cmpestrm(v, 16, one().v, 16, FIND_IN_VECT_COMPL);
-#else
+}
 #endif
+inline epu8 PTransf16::image_mask_ref(bool complement) const {
+    epu8 res{};
+    for (auto x : *this)
+        if (x != 0xFF)
+             res[x] = 0xFF;
+    return complement ? static_cast<epu8>(!res) : res;
 }
+
 inline uint32_t PTransf16::image_bitset(bool complement) const {
     return simde_mm_movemask_epi8(image_mask(complement));
 }
@@ -73,10 +80,9 @@ inline PTransf16 PTransf16::left_one() const {
 inline uint32_t PTransf16::rank_ref() const {
     TPUBuild<epu8>::array tmp{};
     static_assert(TPUBuild<epu8>::size == 16, "Wrong size of EPU8 array");
-    for (size_t i = 0; i < 16; i++) {
-        if (v[i] != 0xFF)
-            tmp[v[i]] = 1;
-    }
+    for (auto x : *this)
+        if (x != 0xFF)
+            tmp[x] = 1;
     return std::accumulate(tmp.begin(), tmp.end(), uint8_t(0));
 }
 inline uint32_t PTransf16::rank() const {
diff --git a/include/vect_generic.hpp b/include/vect_generic.hpp
index 594a14ea..6c98f281 100644
--- a/include/vect_generic.hpp
+++ b/include/vect_generic.hpp
@@ -222,10 +222,10 @@ namespace std {
 template <size_t _Size, typename Expo>
 std::ostream &operator<<(std::ostream &stream,
                          const HPCombi::VectGeneric<_Size, Expo> &v) {
-    stream << "[" << std::setw(2) << unsigned(v[0]);
+    stream << "{" << std::setw(2) << unsigned(v[0]);
     for (unsigned i = 1; i < _Size; ++i)
         stream << "," << std::setw(2) << unsigned(v[i]);
-    stream << "]";
+    stream << "}";
     return stream;
 }
 
diff --git a/tests/test_epu.cpp b/tests/test_epu.cpp
index 7f8fe36d..fe80eb77 100644
--- a/tests/test_epu.cpp
+++ b/tests/test_epu.cpp
@@ -194,18 +194,18 @@ TEST_CASE_METHOD(Fix, "Epu8::less", "[Epu8][010]") {
 }
 
 TEST_CASE_METHOD(Fix, "Epu8::permuted", "[Epu8][011]") {
-    REQUIRE(equal(
+    REQUIRE_THAT(
         permuted(epu8{0, 1, 3, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15},
                  epu8{3, 2, 5, 1, 4, 0, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}),
-        epu8{2, 3, 5, 1, 4, 0, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}));
-    REQUIRE(equal(
+        Equals(epu8{2, 3, 5, 1, 4, 0, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}));
+    REQUIRE_THAT(
         permuted(epu8{3, 2, 5, 1, 4, 0, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15},
                  epu8{0, 1, 3, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}),
-        epu8{3, 2, 1, 5, 4, 0, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}));
-    REQUIRE(equal(
+        Equals(epu8{3, 2, 1, 5, 4, 0, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}));
+    REQUIRE_THAT(
         permuted(epu8{3, 2, 5, 1, 4, 0, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15},
                  epu8{2, 2, 1, 2, 3, 6, 12, 4, 5, 16, 17, 11, 12, 13, 14, 15}),
-        epu8{5, 5, 2, 5, 1, 6, 12, 4, 0, 3, 2, 11, 12, 13, 14, 15}));
+        Equals(epu8{5, 5, 2, 5, 1, 6, 12, 4, 0, 3, 2, 11, 12, 13, 14, 15}));
 }
 
 TEST_CASE_METHOD(Fix, "Epu8::shifted_left", "[Epu8][012]") {
diff --git a/tests/test_perm16.cpp b/tests/test_perm16.cpp
index d75e3146..8d3278e6 100644
--- a/tests/test_perm16.cpp
+++ b/tests/test_perm16.cpp
@@ -92,32 +92,55 @@ TEST_CASE("PTransf16::hash", "[PTransf16][001]") {
     REQUIRE(std::hash<PTransf16>()(PTransf16({4, 5, 0}, {9, 0, 1})) != 0);
 }
 
-// TODO uncomment
-// TEST_CASE("PTransf16::image_mask", "[PTransf16][002]") {
-//     REQUIRE(equal(PTransf16({}).image_mask(), Epu8(FF));
-//     REQUIRE(equal(PTransf16({}).image_mask(false), Epu8(FF));
-//     REQUIRE(equal(PTransf16({}).image_mask(true), Epu8(0));
-//     REQUIRE(equal(PTransf16({4, 4, 4, 4}).image_mask(), Epu8({0, 0, 0, 0},
-//     FF)); REQUIRE(equal(PTransf16({4, 4, 4, 4}).image_mask(false),
-//                Epu8({0, 0, 0, 0}, FF));
-//     REQUIRE(equal(PTransf16({4, 4, 4, 4}).image_mask(true),
-//                Epu8({FF, FF, FF, FF}, 0));
-//     REQUIRE(equal(PTransf16(Epu8(1)).image_mask(), Epu8({0, FF}, 0));
-//     REQUIRE(equal(PTransf16(Epu8(2)).image_mask(), Epu8({0, 0, FF}, 0));
-//     REQUIRE(equal(PTransf16(Epu8({2, 2, 2, 0xf}, 2)).image_mask(),
-//                Epu8({0, 0, FF, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, FF}, 0));
-//     REQUIRE(equal(
-//         PTransf16(Epu8({0, 2, 2, 0xf, 2, 2, 2, 2, 5, 2}, 2)).image_mask(),
-//         Epu8({FF, 0, FF, 0, 0, FF, 0, 0, 0, 0, 0, 0, 0, 0, 0, FF}, 0));
-//     REQUIRE(equal(
-//         PTransf16(Epu8({0, 2, 2, 0xf, 2, 2, 2, 2, 5, 2},
-//         2)).image_mask(false), Epu8({FF, 0, FF, 0, 0, FF, 0, 0, 0, 0, 0, 0,
-//         0, 0, 0, FF}, 0));
-//     REQUIRE(equal(
-//         PTransf16(Epu8({0, 2, 2, 0xf, 2, 2, 2, 2, 5, 2},
-//         2)).image_mask(true), Epu8({0, FF, 0, FF, FF, 0, FF, FF, FF, FF, FF,
-//         FF, FF, FF, FF, 0}, 0));
-// }
+TEST_CASE("PTransf16::image_mask", "[PTransf16][002]") {
+    REQUIRE_THAT(PTransf16({}).image_mask(), Equals(Epu8(FF)));
+    REQUIRE_THAT(PTransf16({}).image_mask(false), Equals(Epu8(FF)));
+    REQUIRE_THAT(PTransf16({}).image_mask(true), Equals(Epu8(0)));
+    REQUIRE_THAT(PTransf16({4, 4, 4, 4}).image_mask(),
+                 Equals(Epu8({0, 0, 0, 0}, FF)));
+    REQUIRE_THAT(PTransf16({4, 4, 4, 4}).image_mask(false),
+                 Equals(Epu8({0, 0, 0, 0}, FF)));
+    REQUIRE_THAT(PTransf16({4, 4, 4, 4}).image_mask(true),
+                 Equals(Epu8({FF, FF, FF, FF}, 0)));
+    REQUIRE_THAT(PTransf16(Epu8(1)).image_mask(), Equals(Epu8({0, FF}, 0)));
+    REQUIRE_THAT(PTransf16(Epu8(2)).image_mask(), Equals(Epu8({0, 0, FF}, 0)));
+    REQUIRE_THAT(PTransf16(Epu8({2, 2, 2, 0xf}, 2)).image_mask(),
+                 Equals(Epu8({0, 0, FF, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, FF}, 0)));
+    REQUIRE_THAT(
+        PTransf16(Epu8({0, 2, 2, 0xf, 2, 2, 2, 2, 5, 2}, 2)).image_mask(),
+        Equals(Epu8({FF, 0, FF, 0, 0, FF, 0, 0, 0, 0, 0, 0, 0, 0, 0, FF}, 0)));
+    REQUIRE_THAT(
+        PTransf16(Epu8({0, 2, 2, 0xf, 2, 2, 2, 2, 5, 2}, 2)).image_mask(false),
+        Equals(Epu8({FF, 0, FF, 0, 0, FF, 0, 0, 0, 0, 0, 0, 0, 0, 0, FF}, 0)));
+    REQUIRE_THAT(
+        PTransf16(Epu8({0, 2, 2, 0xf, 2, 2, 2, 2, 5, 2}, 2)).image_mask(true),
+        Equals(Epu8({0, FF, 0, FF, FF, 0, FF, FF, FF, FF, FF, FF, FF, FF, FF, 0}, 0)));
+}
+
+TEST_CASE("PTransf16::image_mask_ref_ref", "[PTransf16][002]") {
+    REQUIRE_THAT(PTransf16({}).image_mask_ref(), Equals(Epu8(FF)));
+    REQUIRE_THAT(PTransf16({}).image_mask_ref(false), Equals(Epu8(FF)));
+    REQUIRE_THAT(PTransf16({}).image_mask_ref(true), Equals(Epu8(0)));
+    REQUIRE_THAT(PTransf16({4, 4, 4, 4}).image_mask_ref(),
+                 Equals(Epu8({0, 0, 0, 0}, FF)));
+    REQUIRE_THAT(PTransf16({4, 4, 4, 4}).image_mask_ref(false),
+                 Equals(Epu8({0, 0, 0, 0}, FF)));
+    REQUIRE_THAT(PTransf16({4, 4, 4, 4}).image_mask_ref(true),
+                 Equals(Epu8({FF, FF, FF, FF}, 0)));
+    REQUIRE_THAT(PTransf16(Epu8(1)).image_mask_ref(), Equals(Epu8({0, FF}, 0)));
+    REQUIRE_THAT(PTransf16(Epu8(2)).image_mask_ref(), Equals(Epu8({0, 0, FF}, 0)));
+    REQUIRE_THAT(PTransf16(Epu8({2, 2, 2, 0xf}, 2)).image_mask_ref(),
+                 Equals(Epu8({0, 0, FF, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, FF}, 0)));
+    REQUIRE_THAT(
+        PTransf16(Epu8({0, 2, 2, 0xf, 2, 2, 2, 2, 5, 2}, 2)).image_mask_ref(),
+        Equals(Epu8({FF, 0, FF, 0, 0, FF, 0, 0, 0, 0, 0, 0, 0, 0, 0, FF}, 0)));
+    REQUIRE_THAT(
+        PTransf16(Epu8({0, 2, 2, 0xf, 2, 2, 2, 2, 5, 2}, 2)).image_mask_ref(false),
+        Equals(Epu8({FF, 0, FF, 0, 0, FF, 0, 0, 0, 0, 0, 0, 0, 0, 0, FF}, 0)));
+    REQUIRE_THAT(
+        PTransf16(Epu8({0, 2, 2, 0xf, 2, 2, 2, 2, 5, 2}, 2)).image_mask_ref(true),
+        Equals(Epu8({0, FF, 0, FF, FF, 0, FF, FF, FF, FF, FF, FF, FF, FF, FF, 0}, 0)));
+}
 
 // TODO uncomment
 // TEST_CASE("PTransf16::left_one", "[PTransf16][003]") {