CCR Exif v1.5.1

What it is: a small class library to edit, create and delete Exif (and now IPTC) metadata in JPEG files, Exif being the sort of metadata that most digital cameras write.

Features: 100% pure Delphi code — doesn’t use (say) LibExif, LibTiff or GDI+; reads/writes both small- and big-endian data; surfaces both standard Exif and Windows Explorer tags; understands the tag structures of Canon and Panasonic maker notes; protects maker note offsets when saving; keeps any associated XMP data in sync when changing Exif tags; includes standalone IPTC and XMP reader/writer classes.

Limitations: freeform editing not implemented for maker note tags yet.

Basic usage:

uses
  CCR.Exif;

procedure ReadCameraMakeAndModel(const FileName: string;
  out Make, Model: string);
var
  ExifData: TExifData;
begin
  ExifData := TExifData.Create;
  try
    ExifData.LoadFromGraphic(FileName);
    Make := ExifData.CameraMake;
    Model := ExifData.CameraModel;
  finally
    ExifData.Free;
  end;
end;

The preferred way to edit metadata is to use a LoadFromGraphic -> property setting -> SaveToGraphic cycle on a relevant class instance — TExifData for Exif data, TIPTCData for IPTC, and TXMPPacket for XMP:

uses
  CCR.Exif;

procedure SetSomeExifTags(const FileName: string);
var
  ExifData: TExifData;
begin
  ExifData := TExifData.Create;
  try
    ExifData.LoadFromGraphic(FileName);
    ExifData.Subject := 'Wimbledon Tennis';
    ExifData.SetKeyWords(['tennis', 'Wimbledon', 'match', 'SW19']);
    //Exif uses the degrees/minutes/seconds GPS format
    ExifData.GPSLatitude.Assign(51, 26, 1.48, ltNorth);
    ExifData.GPSLongitude.Assign(0, 12, 50.63, lnWest);
    ExifData.SaveToGraphic(FileName);
  finally
    ExifData.Free;
  end;
end;

 

uses
  CCR.Exif.IPTC;

procedure SetIPTCHeadlineAndCredit(const FileName,
  NewHeadline, NewCredit: string);
var
  IPTCData: TIPTCData;
begin
  IPTCData := TIPTCData.Create;
  try
    IPTCData.LoadFromGraphic(FileName);
    IPTCData.Headline := NewHeadline;
    IPTCData.Credit := NewCredit;
    IPTCData.SaveToGraphic(FileName);
  finally
    IPTCData.Free;
  end;
end;

Lastly, say you want to delete all Exif tags with binary (‘undefined’) data in a certain file. To cycle through the tags, you use the for-in syntax; on each iteratrion, you can then check the data type and call Delete as required:

uses
  CCR.Exif.TiffUtils{not needed before v1.5.0}, CCR.Exif;

procedure StripBinaryTags(const FileName: string);
var
  ExifData: TExifData;
  Section: TExifSection;
  Tag: TExifTag;
begin
  ExifData := TExifData.Create;
  try
    ExifData.LoadFromGraphic(FileName);
    for Section in ExifData do
      for Tag in Section do
        if Tag.DataType = tdUndefined then
          Tag.Delete;
    ExifData.SaveToGraphic(FileName);
  finally
    ExifData.Free;
  end;
end;

Documentation: the ZIP and repository (see below) includes a PDF documenting many properties and freestanding routines. There’s also various demos included.

Supported Delphi versions: Delphi 2006 and up, preferably Delphi 2007 and up. Supports XE2’s OS X and Win64 targets, though not iOS since the Delphi compiler and RTL are required.

Licence: MPL 1.1 (text here).

Download: the code in the form of a Subversion repository is on Google Code here – this is the recommended way to get it. However, a ZIP file containing the latest stable release is also available as the top link here.

Bug reports: it’s not exactly the most optimum way of doing things for sure, but if you have any issues or suggestions, please add a comment to the post announcing the current release (the comments below concern the 0.9.0 and 0.9.5 releases). Unfortunately, the theme I’m using messes up the display of nested comments more than three levels deep, so please keep that in mind when deciding whether to reply to a previous comment or just add a new one.

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