TMI #163 Support for TIFF containing signed integral other than 16 bit.

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

@@ -521,10 +521,16 @@ public class TIFFImageReader extends ImageReaderBase {
             case TIFFBaseline.SAMPLEFORMAT_UINT:
                 return bitsPerSample <= 8 ? DataBuffer.TYPE_BYTE : bitsPerSample <= 16 ? DataBuffer.TYPE_USHORT : DataBuffer.TYPE_INT;
             case TIFFExtension.SAMPLEFORMAT_INT:
-                if (bitsPerSample == 16) {
+                switch (bitsPerSample) {
-                    return DataBuffer.TYPE_SHORT;
+                    case 8:
+                        return DataBuffer.TYPE_BYTE;
+                    case 16:
+                        return DataBuffer.TYPE_SHORT;
+                    case 32:
+                        return DataBuffer.TYPE_INT;
                 }
-                throw new IIOException("Unsupported BitsPerSample for SampleFormat 2/Signed Integer (expected 16): " + bitsPerSample);
+
+                throw new IIOException("Unsupported BitsPerSample for SampleFormat 2/Signed Integer (expected 8/16/32): " + bitsPerSample);
             case TIFFExtension.SAMPLEFORMAT_FP:
                 throw new IIOException("Unsupported TIFF SampleFormat: 3 (Floating point)");
             case TIFFExtension.SAMPLEFORMAT_UNDEFINED:

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

@@ -82,6 +82,7 @@ public class TIFFImageReaderTest extends ImageReaderAbstractTest<TIFFImageReader
                 new TestData(getClassLoaderResource("/tiff/cmyk_jpeg_no_profile.tif"), new Dimension(150, 63)), // CMYK, JPEG compressed, no ICC profile
                 new TestData(getClassLoaderResource("/tiff/cmyk_jpeg.tif"), new Dimension(100, 100)), // CMYK, JPEG compressed, with ICC profile
                 new TestData(getClassLoaderResource("/tiff/grayscale-alpha.tiff"), new Dimension(248, 351)), // Gray + unassociated alpha
+                new TestData(getClassLoaderResource("/tiff/signed-integral-8bit.tif"), new Dimension(439, 167)), // 8 bit gray, *signed* integral
                 // CCITT
                 new TestData(getClassLoaderResource("/tiff/ccitt/group3_1d.tif"), new Dimension(6, 4)), // B/W, CCITT T4 1D
                 new TestData(getClassLoaderResource("/tiff/ccitt/group3_1d_fill.tif"), new Dimension(6, 4)), // B/W, CCITT T4 1D