rexif  --The library to handle JPEG/EXIF for Ruby

What's Rexif?

Rexif is a pure ruby library for handling JPEG/EXIF formatted images.

Rexif consists of two libraries; rjpeg.rb (for JPEG) and rexif.rb (for EXIF).

Requirements

• Ruby 1.6.x or higher
• A little bit of your energy :)

Download

The latest version is rexif-0.4 (Feb.17.2003.).

Old versions are here.

Installation

% su
# ruby install.rb

Usage

See API reference document for detail.

1) Processing after parseing

require 'rexif'

Jpeg::use_class_for(Jpeg::Segment::APP1,Exif)
j=Jpeg::load('EXIF_FILE.JPG')
if(j.app1.is_exif?)
    puts j.app1.ifd0.marker
end

2) Processing with parseing

require 'rexif'

Jpeg::load('EXIF_FILE.JPG'){|seg|
    if(seg.marker==Jpeg::Segment::APP1)
         Exif.new(seg.marker,seg.byte_data){|dir|
              if(dir.tag==Exif::Ifd::Directory::Maker)
                  puts dir
	      end
              dir
         }
    else
        seg
    end
}

In this method, each return value of Jpeg::load()'s and Exif::new()'s block is treated as Jpeg segment data and Exif directory data, and those return values are stored to Jpeg object and Exif object.

Copying

Copyright © 2003 NISHI Takao <zophos@koka-in.org> All rights reserved.
This is free software with ABSOLUTELY NO WARRANTY.

You can redistribute it and/or modify it under the terms of Ruby's licence.

Restrictions

• Decoding of JPEG image is not supported, and will NOT be supported through the future.
• A thumbnail image which formated in TIFF is not supported.
• MakerNote is not parsed.
• Enough testing to rewrite EXIF do not have done yet.

Changes

0.3 -> 0.4 (2003/2/17)

• Jpeg included Enumerable module. Many methods were changed.
• Exif#byte_data bug fixed.

0.2 -> 0.3 (2003/2/13)

• On call with block for Jpeg and Exif class, a retrun value of block will be stored to call object as the segment or directory value.
• All of Japanese API reference documents has been written.

0.1 -> 0.2 (2003/2/12)

• Some documentation added.
• Jpeg#to_s and Jpeg::Segment#to_s methods renamed to dump.
• Alredy, Exif and Exif::Ifd class have direct-access methods to Ifds and Directories.

0.0 -> 0.1 (2003/2/4)

• Jpeg::Marker class and many methods renamed.
• Return value of Exif::Ifd::Directory#value changed from Array to native object.
• Some sample applications added.

See Change Log for detail.