private void checkThumbnail(ExifData exifData) {
IfdData ifd1 = exifData.getIfdData(IfdId.TYPE_IFD_1);
if (ifd1 != null) {
if (ifd1.getTag(ExifTag.TAG_COMPRESSION).getUnsignedShort(0) == ExifTag.Compression.JPEG) {
assertTrue(exifData.hasCompressedThumbnail());
byte[] thumbnail = exifData.getCompressedThumbnail();
assertTrue(BitmapFactory.decodeByteArray(thumbnail, 0, thumbnail.length) != null);
} else {
// Try to check the strip count with the formula provided by EXIF spec.
int planarType = ExifTag.PlanarConfiguration.CHUNKY;
ExifTag planarTag = ifd1.getTag(ExifTag.TAG_PLANAR_CONFIGURATION);
if (planarTag != null) {
planarType = planarTag.getUnsignedShort(0);
}
ExifTag heightTag = ifd1.getTag(ExifTag.TAG_IMAGE_LENGTH);
ExifTag rowPerStripTag = ifd1.getTag(ExifTag.TAG_ROWS_PER_STRIP);
int imageLength = getUnsignedIntOrShort(heightTag);
int rowsPerStrip = getUnsignedIntOrShort(rowPerStripTag);
int stripCount = ifd1.getTag(ExifTag.TAG_STRIP_OFFSETS).getComponentCount();
if (planarType == ExifTag.PlanarConfiguration.CHUNKY) {
assertTrue(stripCount == (imageLength + rowsPerStrip - 1) / rowsPerStrip);
} else {
ExifTag samplePerPixelTag = ifd1.getTag(ExifTag.TAG_SAMPLES_PER_PIXEL);
int samplePerPixel = samplePerPixelTag.getUnsignedShort(0);
assertTrue(
stripCount == (imageLength + rowsPerStrip - 1) / rowsPerStrip * samplePerPixel);
}
for (int i = 0; i < stripCount; i++) {
ExifTag byteCountTag = ifd1.getTag(ExifTag.TAG_STRIP_BYTE_COUNTS);
if (byteCountTag.getDataType() == ExifTag.TYPE_UNSIGNED_SHORT) {
assertEquals(byteCountTag.getUnsignedShort(i), exifData.getStrip(i).length);
} else {
assertEquals(byteCountTag.getUnsignedLong(i), exifData.getStrip(i).length);
}
}
}
}
}
