Writing Exif Metadata to JPEG

[lichtemo]

Hello,

I want to write Metadata to a JPEg image using the Exif 'XPComment' field.
Because the standart Java libraries does not support writing metadata I tried using the JAI (Java Advanced Imaging) and Sanselan (Commons Sanselan - Commons ) but I was not able to find an example or something else which helps me to create a working code.
Does anybody know how I can do this?

[travishein]

Sanselan: a Pure-Java Image Library.

which is really now

http://commons.apache.org/sanselan/

[lichtemo]

I know that and I tried to create some code which can write comments. But it fails writing the XPComment. It supports the UserCommet field (if you replace the used Variables).
My code is:

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
 
import org.apache.sanselan.ImageReadException;
import org.apache.sanselan.ImageWriteException;
import org.apache.sanselan.Sanselan;
import org.apache.sanselan.common.IImageMetadata;
import org.apache.sanselan.formats.jpeg.JpegImageMetadata;
import org.apache.sanselan.formats.jpeg.exifRewrite.ExifRewriter;
import org.apache.sanselan.formats.tiff.TiffField;
import org.apache.sanselan.formats.tiff.TiffImageMetadata;
import org.apache.sanselan.formats.tiff.constants.ExifTagConstants;
import org.apache.sanselan.formats.tiff.constants.TagInfo;
import org.apache.sanselan.formats.tiff.constants.TiffConstants;
import org.apache.sanselan.formats.tiff.constants.TiffFieldTypeConstants;
import org.apache.sanselan.formats.tiff.write.TiffOutputDirectory;
import org.apache.sanselan.formats.tiff.write.TiffOutputField;
import org.apache.sanselan.formats.tiff.write.TiffOutputSet;
 
 
 
public class Test2 {
    
    private static TiffField t;
    
    /**
     * Read metadata from image file and display it. 
     * @param file
     */
    public static void readMetaData(File file) {
        IImageMetadata metadata = null;
        try {
            metadata = Sanselan.getMetadata(file);
        } catch (ImageReadException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        if (metadata instanceof JpegImageMetadata) {
            JpegImageMetadata jpegMetadata = (JpegImageMetadata) metadata;
            System.out.println("\nFile: " + file.getPath());
            printTagValue(jpegMetadata,
                TiffConstants.TIFF_TAG_XRESOLUTION);
            printTagValue(jpegMetadata,
                TiffConstants.TIFF_TAG_DATE_TIME);
            printTagValue(jpegMetadata,
                TiffConstants.EXIF_TAG_DATE_TIME_ORIGINAL);
            printTagValue(jpegMetadata,
                TiffConstants.EXIF_TAG_CREATE_DATE);
            printTagValue(jpegMetadata,
                TiffConstants.EXIF_TAG_ISO);
            printTagValue(jpegMetadata,
                TiffConstants.EXIF_TAG_SHUTTER_SPEED_VALUE);
            printTagValue(jpegMetadata,
                TiffConstants.EXIF_TAG_APERTURE_VALUE);
            printTagValue(jpegMetadata,
                TiffConstants.EXIF_TAG_BRIGHTNESS_VALUE);
 
            // simple interface to GPS data
            TiffImageMetadata exifMetadata = jpegMetadata.getExif();
            if (exifMetadata != null) {
                try {
                    TiffImageMetadata.GPSInfo gpsInfo = exifMetadata.getGPS();
                    if (null != gpsInfo) {
                        double longitude = gpsInfo.getLongitudeAsDegreesEast();
                        double latitude = gpsInfo.getLatitudeAsDegreesNorth();
                        System.out.println("    " +
                            "GPS Description: " + gpsInfo);
                        System.out.println("    " +
                            "GPS Longitude (Degrees East): " +
                            longitude);
                        System.out.println("    " +
                            "GPS Latitude (Degrees North): " +
                            latitude);
                    }
                } catch (ImageReadException e) {
                    e.printStackTrace();
                }
            }
 
            System.out.println("EXIF items -");
            ArrayList<?> items = jpegMetadata.getItems();
            for (int i = 0; i < items.size(); i++) {
                Object item = items.get(i);
                System.out.println(item.getClass());
                System.out.println(((TiffImageMetadata.Item)item).getTiffField());
                t =((TiffImageMetadata.Item)item).getTiffField();
                System.out.println("    " + "item: " +
                    item);
            }
            System.out.println();
        }
    }
 
    private static void printTagValue(
        JpegImageMetadata jpegMetadata, TagInfo tagInfo) {
        TiffField field = jpegMetadata.findEXIFValue(tagInfo);
        if (field == null) {
            System.out.println(tagInfo.name + ": " +
                "Not Found.");
        } else {
            System.out.println(tagInfo.name + ": " +
                field.getValueDescription());
        }
    }
 
    
    /**
     * Example of adding an EXIF item to metadata, in this case using ImageHistory field. 
     * (I have no idea if this is an appropriate use of ImageHistory, or not, just picked
     * a field to update that looked like it wasn't commonly mucked with.)
     * @param file
     */
    public static void addImageHistoryTag(File file) {
        File dst = null;
        IImageMetadata metadata = null;
        JpegImageMetadata jpegMetadata = null;
        TiffImageMetadata exif = null;
        OutputStream os = null;
        TiffOutputSet outputSet = new TiffOutputSet();
 
        // establish metadata
        try {
            metadata = Sanselan.getMetadata(file);
        } catch (ImageReadException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        // establish jpegMedatadata
        if (metadata != null) {
            jpegMetadata = (JpegImageMetadata) metadata;
        }
 
        // establish exif
        if (jpegMetadata != null) {
            exif = jpegMetadata.getExif();
        }
 
        // establish outputSet
        if (exif != null) {
            try {
                outputSet = exif.getOutputSet();
            } catch (ImageWriteException e) {
                e.printStackTrace();
            }
        }
 
        if (outputSet != null) {         
            // check if field already EXISTS - if so remove         
            TiffOutputField imageHistoryPre = outputSet
                    .findField(TiffConstants.EXIF_TAG_XPCOMMENT);
            if (imageHistoryPre != null) {
                System.out.println("REMOVE");
                outputSet.removeField(TiffConstants.EXIF_TAG_XPCOMMENT);
            }                    
            // add field 
            try {  
                String fieldData = "Hallo"; 
                  TiffOutputField imageHistory = new TiffOutputField(
                          TiffConstants.EXIF_TAG_XPCOMMENT, 
                          TiffFieldTypeConstants.FIELD_TYPE_BYTE, 
                          fieldData.length(), 
                          fieldData.getBytes());
//            
                  TiffOutputDirectory exifDirectory = outputSet.getOrCreateExifDirectory();
                  exifDirectory.add(imageHistory);
                 
                
               
            } catch (ImageWriteException e) {
 
                e.printStackTrace();
            }
        }
        
        try {
            dst = new File("Hallo.jpg");
            os = new FileOutputStream(dst);
            os = new BufferedOutputStream(os);
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        // write/update EXIF metadata to output stream
        try {
            new ExifRewriter().updateExifMetadataLossless(file,
                os, outputSet);
        } catch (ImageReadException e) {
            e.printStackTrace();
        } catch (ImageWriteException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                }
            }
        }
        
//        file.delete();
//      dst.renameTo(file);        
    }
 
 
    
    public static void main(String[] args) {
        readMetaData(new File ("Adler (2).jpg"));
        addImageHistoryTag(new File ("Adler (2).jpg"));
        readMetaData(new File ("Hallo.jpg"));
    }
 
}

I get the following output:

File: Adler (2).jpg
XResolution: 1
Date Time: Not Found.
Date Time Original: Not Found.
Create Date: Not Found.
ISO: Not Found.
Shutter Speed Value: Not Found.
Aperture Value: Not Found.
Brightness Value: Not Found.
EXIF items -
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
282 (0x11a: XResolution): 1 (1 Rational)
item: XResolution: 1
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
283 (0x11b: YResolution): 1 (1 Rational)
item: YResolution: 1
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
296 (0x128: Resolution Unit): 1 (1 Short)
item: Resolution Unit: 1
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
531 (0x213: YCbCr Positioning): 1 (1 Short)
item: YCbCr Positioning: 1
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
40092 (0x9c9c: XPComment): 104, 0, 103, 0, 102, 0, 0, 0 (8 Byte)
item: XPComment: 104, 0, 103, 0, 102, 0, 0, 0

REMOVE

File: Hallo.jpg
XResolution: 1
Date Time: Not Found.
Date Time Original: Not Found.
Create Date: Not Found.
ISO: Not Found.
Shutter Speed Value: Not Found.
Aperture Value: Not Found.
Brightness Value: Not Found.
EXIF items -
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
282 (0x11a: XResolution): 1 (1 Rational)
item: XResolution: 1
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
283 (0x11b: YResolution): 1 (1 Rational)
item: YResolution: 1
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
296 (0x128: Resolution Unit): 1 (1 Short)
item: Resolution Unit: 1
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
531 (0x213: YCbCr Positioning): 1 (1 Short)
item: YCbCr Positioning: 1
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
34665 (0x8769: Exif Offset): 74 (1 Long)
item: Exif Offset: 74
class org.apache.sanselan.formats.tiff.TiffImageMetadata $Item
40092 (0x9c9c: Unknown Tag): 72, 97, 108, 108, 111 (5 Byte)
item: Unknown Tag (0x9c9c): 72, 97, 108, 108, 111

You see that the knew image also includes a 0x9c9c tag, but this is why ever "Unknown" and windows also not show it.