#865 TIFF: Half decoding fix, now uses standard conversion.

haraldk · Nov 15, 2023 · 0378f50 · 0378f50
1 parent 1d3a7fe
commit 0378f50
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Showing 2 changed files with 12 additions and 10 deletions.
diff --git a/imageio/imageio-metadata/src/main/java/com/twelvemonkeys/imageio/metadata/tiff/Half.java b/imageio/imageio-metadata/src/main/java/com/twelvemonkeys/imageio/metadata/tiff/Half.java
@@ -87,11 +87,6 @@ public static float shortBitsToFloat(final short shortBits) {
         }
         else if (exponent != 0) {                   // Normalized value
             exponent += 0x1c000;                    // exp - 15 + 127
-
-            // Smooth transition
-            if (mantissa == 0 && exponent > 0x1c400) {
-                return Float.intBitsToFloat((shortBits & 0x8000) << 16 | exponent << 13 | 0x3ff);
-            }
         }
         else if (mantissa != 0) {                   // && exp == 0 -> subnormal
             exponent = 0x1c400;                     // Make it normal

diff --git a/imageio/imageio-metadata/src/test/java/com/twelvemonkeys/imageio/metadata/tiff/HalfTest.java b/imageio/imageio-metadata/src/test/java/com/twelvemonkeys/imageio/metadata/tiff/HalfTest.java
@@ -1,16 +1,16 @@
 package com.twelvemonkeys.imageio.metadata.tiff;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
+import com.twelvemonkeys.io.FastByteArrayOutputStream;
+
+import org.junit.Test;
 
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.util.Random;
 
-import org.junit.Test;
-
-import com.twelvemonkeys.io.FastByteArrayOutputStream;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 /**
  * HalfTest.
@@ -36,6 +36,13 @@ public void testRoundTrip() {
         }
     }
 
+    @Test
+    public void testExactEncoding() {
+        for (short half = -2048; half < 2048; half++) {
+            assertEquals(String.valueOf(half), half, Half.shortBitsToFloat(Half.floatToShortBits(half)), 0);
+        }
+    }
+
     @Test
     public void testRoundTripBack() {
         for (int i = 0; i < 1024; i++) {