Fallback for missing TIFFTag.PhotometricInterpretation

imageio/imageio-tiff/src/main/java/com/twelvemonkeys/imageio/plugins/tiff/TIFFImageReader.java

@@ -315,7 +315,7 @@ public class TIFFImageReader extends ImageReaderBase {
 
         int sampleFormat = getSampleFormat();
         int planarConfiguration = getValueAsIntWithDefault(TIFF.TAG_PLANAR_CONFIGURATION, TIFFBaseline.PLANARCONFIG_CHUNKY);
-        int interpretation = getValueAsInt(TIFF.TAG_PHOTOMETRIC_INTERPRETATION, "PhotometricInterpretation");
+        int interpretation = getPhotometricInterpretationWithFallback();
         int samplesPerPixel = getValueAsIntWithDefault(TIFF.TAG_SAMPLES_PER_PIXEL, 1);
         int bitsPerSample = getBitsPerSample();
         int dataType = getDataType(sampleFormat, bitsPerSample);
@@ -545,6 +545,37 @@ public class TIFFImageReader extends ImageReaderBase {
         }
     }
 
+    private int getPhotometricInterpretationWithFallback() throws IIOException {
+        // PhotometricInterpretation is a required TAG, but as it can be guessed this does a fallback that is equal to JAI ImageIO.
+        int interpretation = getValueAsIntWithDefault(TIFF.TAG_PHOTOMETRIC_INTERPRETATION, "PhotometricInterpretation", -1);
+        if (interpretation == -1) {
+            int compression = getValueAsIntWithDefault(TIFF.TAG_COMPRESSION, TIFFBaseline.COMPRESSION_NONE);
+            int samplesPerPixel = getValueAsIntWithDefault(TIFF.TAG_SAMPLES_PER_PIXEL, 1);
+            Entry extraSamplesEntry = currentIFD.getEntryById(TIFF.TAG_EXTRA_SAMPLES);
+            int extraSamples = extraSamplesEntry == null ? 0 : extraSamplesEntry.valueCount();
+
+            if (compression == TIFFBaseline.COMPRESSION_CCITT_MODIFIED_HUFFMAN_RLE
+                    || compression == TIFFExtension.COMPRESSION_CCITT_T4
+                    || compression == TIFFExtension.COMPRESSION_CCITT_T6) {
+                interpretation = TIFFBaseline.PHOTOMETRIC_WHITE_IS_ZERO;
+            }
+            else if (currentIFD.getEntryById(TIFF.TAG_COLOR_MAP) != null) {
+                interpretation = TIFFBaseline.PHOTOMETRIC_PALETTE;
+            }
+            else if ((samplesPerPixel - extraSamples) == 3) {
+                interpretation = TIFFBaseline.PHOTOMETRIC_RGB;
+            }
+            else if ((samplesPerPixel - extraSamples) == 4) {
+                interpretation = TIFFExtension.PHOTOMETRIC_SEPARATED;
+            }
+            else {
+                interpretation = TIFFBaseline.PHOTOMETRIC_BLACK_IS_ZERO;
+            }
+            processWarningOccurred("Missing PhotometricInterpretation, determining fallback: " + interpretation);
+        }
+        return interpretation;
+    }
+
     private int getOpaqueSamplesPerPixel(final int photometricInterpretation) throws IIOException {
         switch (photometricInterpretation) {
             case TIFFBaseline.PHOTOMETRIC_WHITE_IS_ZERO:
@@ -730,7 +761,7 @@ public class TIFFImageReader extends ImageReaderBase {
 
         WritableRaster destRaster = clipToRect(destination.getRaster(), dstRegion, param != null ? param.getDestinationBands() : null);
 
-        final int interpretation = getValueAsInt(TIFF.TAG_PHOTOMETRIC_INTERPRETATION, "PhotometricInterpretation");
+        final int interpretation = getPhotometricInterpretationWithFallback();
         final int compression = getValueAsIntWithDefault(TIFF.TAG_COMPRESSION, TIFFBaseline.COMPRESSION_NONE);
         final int predictor = getValueAsIntWithDefault(TIFF.TAG_PREDICTOR, 1);
         final int planarConfiguration = getValueAsIntWithDefault(TIFF.TAG_PLANAR_CONFIGURATION, TIFFBaseline.PLANARCONFIG_CHUNKY);

imageio/imageio-tiff/src/test/java/com/twelvemonkeys/imageio/plugins/tiff/TIFFImageReaderTest.java

@@ -29,7 +29,9 @@ package com.twelvemonkeys.imageio.plugins.tiff;/*
 import com.twelvemonkeys.imageio.util.ImageReaderAbstractTest;
 import org.junit.Test;
 
+import javax.imageio.ImageIO;
 import javax.imageio.ImageReadParam;
+import javax.imageio.ImageReader;
 import javax.imageio.event.IIOReadWarningListener;
 import javax.imageio.spi.ImageReaderSpi;
 import javax.imageio.stream.ImageInputStream;
@@ -39,9 +41,9 @@ import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.*;
-import static org.junit.Assert.assertNotNull;
 import static org.mockito.Matchers.contains;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.*;
@@ -329,4 +331,39 @@ public class TIFFImageReaderTest extends ImageReaderAbstractTest<TIFFImageReader
         }
     }
 
+    @Test
+    public void testPhotometricInterpretationFallback() throws IOException {
+        String[] files = {
+                "/tiff/guessPhotometric/group4.tif",
+                "/tiff/guessPhotometric/flower-rgb-contig-08.tif",
+                "/tiff/guessPhotometric/flower-separated-planar-08.tif"
+        };
+
+        final int[] results = {
+                TIFFBaseline.PHOTOMETRIC_WHITE_IS_ZERO,
+                TIFFBaseline.PHOTOMETRIC_RGB,
+                TIFFExtension.PHOTOMETRIC_SEPARATED
+        };
+
+        for (int i = 0; i < files.length; i++) {
+            final AtomicBoolean foundWarning = new AtomicBoolean(false);
+            final int expectedResult = results[i];
+
+            try (ImageInputStream iis = ImageIO.createImageInputStream(getClassLoaderResource(files[i]))) {
+                TIFFImageReader reader = createReader();
+
+                reader.setInput(iis);
+                reader.addIIOReadWarningListener(new IIOReadWarningListener() {
+                    @Override
+                    public void warningOccurred(ImageReader source, String warning) {
+                        if (warning.equals("Missing PhotometricInterpretation, determining fallback: " + expectedResult)) {
+                            foundWarning.set(true);
+                        }
+                    }
+                });
+                reader.read(0);
+            }
+            assertTrue("no correct guess for PhotometricInterpretation: " + results[i], foundWarning.get());
+        }
+    }
 }