diff --git a/unitTests/CMakeLists.txt b/unitTests/CMakeLists.txt
index 5c8096c6..60e3b539 100644
--- a/unitTests/CMakeLists.txt
+++ b/unitTests/CMakeLists.txt
@@ -11,6 +11,7 @@ add_executable(unit_tests mainTestRunner.cpp
     test_cr2header_int.cpp
     test_helper_functions.cpp
     test_slice.cpp
+    test_image_int.cpp
     $<TARGET_OBJECTS:exiv2lib_int>
 )
 
diff --git a/unitTests/test_image_int.cpp b/unitTests/test_image_int.cpp
new file mode 100644
index 00000000..a8dd52cc
--- /dev/null
+++ b/unitTests/test_image_int.cpp
@@ -0,0 +1,48 @@
+#include "gtestwrapper.h"
+
+#include <image_int.hpp>
+
+using namespace Exiv2::Internal;
+
+static const unsigned char buf[10] = {'a', 'b', 'c', 1, 4, 0, 'e', 136, 0, 'a'};
+
+TEST(binaryToString, zeroStart)
+{
+    // a, b, c are printable, 1 & 4 are not => '.', 0 at last position => skipped
+    ASSERT_STREQ(binaryToString(buf, 6, 0).c_str(), "abc..");
+
+    // same as previous, but now last element is not ignored since it is not 0
+    ASSERT_STREQ(binaryToString(buf, 5, 0).c_str(), "abc..");
+
+    // same as first, only now the 0 & 136 are converted to '.'
+    ASSERT_STREQ(binaryToString(buf, 8, 0).c_str(), "abc...e.");
+
+    // should result in the same as previously, as trailing zero is ignored
+    ASSERT_STREQ(binaryToString(buf, 9, 0).c_str(), "abc...e.");
+
+    // ensure that the function does not overread when last element != 0
+    ASSERT_STREQ(binaryToString(buf, sizeof(buf), 0).c_str(), "abc...e..a");
+}
+
+TEST(binaryToString, nonZeroStart)
+{
+    // start @ index 1, read 6 characters (until e)
+    ASSERT_STREQ(binaryToString(buf, 6, 1).c_str(), "bc...e");
+
+    // start @ index 3, read until end
+    ASSERT_STREQ(binaryToString(buf, sizeof(buf) - 3, 3).c_str(), "...e..a");
+}
+
+TEST(binaryToString, DataBuf)
+{
+    const Exiv2::DataBuf data_buf(buf, sizeof(buf));
+
+    // same as first case in zeroStart
+    ASSERT_EQ(binaryToString(data_buf, 6, 0), "abc..");
+
+    // try to pass a too large value for size
+    ASSERT_EQ(binaryToString(data_buf, 200, 0), "abc...e..a");
+
+    // make it blow up by setting start larger than zero...
+    ASSERT_EQ(binaryToString(data_buf, 200, 1), "bc...e..a");
+}