Warning: Here, there be noobs.

So, I'm in way over my head with the EXIF library at http://www.drewnoakes.com/code/exif/

I'm trying to pull the thumbnails embedded in the EXIFs of my JPEGs. Ideally, I would be loading them straight from the file, but I've settled on writing them directly to a tiny temporary BMP, which I can reload, because the smattering of examples I can find do just that, and no more.

I'm pretty sure I need to do this:
Code:

ExifDirectory directory = (ExifDirectory)metadata.getDirectory(ExifDirectory.class); 

But every time it reaches that line, it dies and says:
Invalid type: 70
Syntax error: ")" inserted to complete Arguments

I have no idea what that means. Other people have apparently run this line successfully... it seems to have the correct number of parenthesis everywhere... it gives the same error if I just plop "ExifDirectory.class" on a line all by itself.

In case it's relevent, here's the whole shebang. It's pointless, uncommented, and verbose at the moment, because I'm still at the 'cobbling things together' stage.

Code:

String[] picFiles = new String[0];
Metadata[] picData = new Metadata[0];

File picFolder = processing.app.Base.selectFolder("Pick a folder:",new File((String)""),new Frame(""));

String[] allFiles = processing.app.Base.listFiles(picFolder,false);

for (int x = 0; x < allFiles.length; x++){
  if((allFiles[x].substring(allFiles[x].length()-4,allFiles[x].length())).equals(".JPG")){
    picFiles = append(picFiles,allFiles[x]);
    println(picFiles[picFiles.length-1]);
  }
}

for (int x = 0; x < picFiles.length; x++){
  try{
    picData = (Metadata[])append(picData,JpegMetadataReader.readMetadata(new File(picFiles[x])));
    println(str(picData.length));}
   catch(com.drew.imaging.jpeg.JpegProcessingException message){println("Something bad has happened.");}
}

for (int x = 0; x < picData.length; x++){
    try{
	  ExifDirectory directory = (ExifDirectory)picData[x].getDirectory(ExifDirectory.class);
	  directory.writeThumbnail("../../pics/1/thumb.bmp");
    }catch(Exception message){println("Something bad has happened.");}
} 

Neither tweak worked.

I got as far as thinking, "maybe it thinks I'm trying to make a class or something...", but never reached the potential-solution stage.

I thought the Reference: Extended page was the extend of standard processing. All I could find there about files and directories was... nothing... except how to load a file that already lives in the data folder, and I think the first relevant result from the Search box was something crazy and non-processing-Java filled from the Hacks page. These "revisions" you speak of sound like a beautiful wonderland that I should look into..

I really hope someone can help me with this.  I've tried the above instructions, and have made a simple test sketch (below).  When I try to run the sketch, processing says: Cannot find anything named "ExifDirectory"

• I tried fully qualifying the name of the offending class: com.drew.metadata.exif.ExitDirectory, but that doesn't seem to solve the problem.
• I have the Exif library (metadata-extractor-2.3.1.jar) in a code subfolder of my sketch
• I am running Processing 1.06

Code:

import com.drew.*;

public class try_exif extends PApplet 
{

  File jpegFile;
  Metadata testMetaData;

  void setup()
  {

    jpegFile = new File (this.sketchPath + jpegFile.separator + "IMG_2025.jpg");


    try { 
      testMetaData = JpegMetadataReader.readMetadata (jpegFile);
    } 
    catch (JpegProcessingException message) 
    {
      println ("error");
    }

    Directory exifDirectory = testMetaData.getDirectory(((Object)ExifDirectory).getClass());
  }

  void loop ()
  {
  }

}
 

Phil,

Thanks for the suggestions.  As you surmised, I didn't know how imports work in Java.

So, I replaced what I had there before with
Code:

import com.drew.*;
import com.drew.metadata.*;
import com.drew.metadata.exif.*; 

As far as I can tell from the documentation at Code:

drewnoakes.com/code/exif/javadoc/ 

, the ExifDirectory class is located inside com.drew.metadata.exif

I also commented out the
Code:

public class try_exit extends PApplet 

stuff which was suggested in an earlier response to this topic.

I renamed "loop ()" to "draw()" (I also program Arduinos, so I mix things up from time to time).

Unfortunately, I'm still getting the same error.

Got it to work. As fry pointed out, the pre-processor doesn't appreciate the Foo.class syntax...
I chose the easy solution, to put this syntax out of the pre-processor sight! For this, I wrap my functions in a class and put them in a .java file.
Here is my current code. I am trying to see if I can get the thumbnail data directly in a PImage...
ExifReader.pde Code:

import com.drew.imaging.*;
import com.drew.imaging.jpeg.*;
import com.drew.metadata.*;
import com.drew.metadata.exif.*;
import com.drew.metadata.iptc.*;
import com.drew.metadata.jpeg.*;

void setup()
{
  size(800, 800);
  background(0);

  String pictureFolder = selectFolder("Image Folder");

  if (pictureFolder == null)
  {
    println("Canceled");
    return;
  }
  File pictFolder = new File(pictureFolder);
  File[] pictureFiles = pictFolder.listFiles(
	new FilenameFilter()
	{
	  boolean accept(File dir, String name)
	  {
	    String fn = name.toLowerCase();
	    // Exif is only in these files, no?
	    return fn.endsWith(".jpg") || fn.endsWith(".jpeg");
	  }
	}
  );
  int x = 10, y = 10;
  int maxHeight = 0;
  for (int fi = 0; fi < pictureFiles.length; fi++)
  {
    File pf = null;
    Metadata metadata = null;
    try
    {
	pf = pictureFiles[fi];
	println("\n" + pf);
	metadata = JpegMetadataReader.readMetadata(pf);
    }
    catch (JpegProcessingException ex)
    {
	println("Ouch! " + pf.getName());
    }
    if (metadata != null)
    {
	ExifProcessing.ShowInformation(metadata);
	ExifProcessing.WriteThumbnail(metadata, pf);
    }
  }
  exit();
}
 

ExifProcessing.java Code:

import java.util.*;
import java.io.*;

import java.awt.image.BufferedImage;

import com.drew.imaging.*;
import com.drew.imaging.jpeg.*;
import com.drew.metadata.*;
import com.drew.metadata.exif.*;
import com.drew.metadata.iptc.*;
import com.drew.metadata.jpeg.*;

class ExifProcessing
{
  static void ShowInformation(Metadata metadata)
  {
    Iterator directories = metadata.getDirectoryIterator();
    while (directories.hasNext())
    {
	Directory directory = (Directory) directories.next();
	// iterate through tags and print to System.out
	Iterator tags = directory.getTagIterator();
	while (tags.hasNext())
	{
	  Tag tag = (Tag) tags.next();
	  // use Tag.toString()
	  System.out.println(tag);
	}
    }
  }

  static void WriteThumbnail(Metadata metadata, File pictureFile)
  {
    ExifDirectory dir = (ExifDirectory) metadata.getDirectory(ExifDirectory.class);
    if (!dir.containsThumbnail())
    {
	System.out.println("No thumbnail");
	return;
    }
    String fileName = pictureFile.getName();
    File file = new File(pictureFile.getParentFile().getPath(),
	  fileName.replaceAll("\\.jpe?g$", ".thumb.jpg"));
    try
    {
	dir.writeThumbnail(file.getAbsolutePath());
	System.out.println("Thumbnail written: " + file.getAbsolutePath());
    }
    catch (MetadataException me)
    {
	System.out.println(me);
    }
    catch (IOException ioe)
    {
	System.out.println(ioe);
    }
  }
}
 

thank you PhiLo!  I am now unstuck.  

Michael