An interview with Phil Harvey
2006-06-08 von Thorsten Schnebeck
(This is the original version of an interview I (e4l) did with Phil Harvey (PH) the creator of ExifTool in 2005. You can find the German translation here.)
e4l: Everything starts with a question in our forum concerning a generic exif writing tool which was not possible to do with ExifTool at that time.
Since then you started a remarkble pace to evolve and redesign ExifTool and now we noticed ExifTool 5.00 – a program standing on its own in Linux land, though written in Perl it runs on every platform.
So we want to know more about the guy who releases 3 updates in two days :-)
PH: (laugthing) True. I do turn out frequent updates. I don’t see the point in waiting if I fix a bug or make a useful improvement. Also, I have a script that automates the release process, so for me it is as easy as typing the word ‘publish’.
e4l: Can you please introduce yourself? Do you have a picture to show to our readers?
PH: I don’t have many pictures of myself – I’m usually the one behind the camera – but I’ve attached one that my wife took soon after I first got my 300D.
Phil Harvey and his wife (making the photo ;-)
I have an M.Sc. in nuclear physics, and am currently working at Queen’s University as a programmer for the Sudbury Neutrino Observatory project. My interest has always been in graphics programming, although I have done my fair share of data acquisition and data processing systems. I have written much of the C++ data acquisition code for SNO, as well as their primary event viewer (called XSNOED, it is a C++ X-Windows application, and I am webmaster for the SNO site.
e4l: What are your preferred photo themes, do you have a longer photo carreer?
PH: I’ve been taking pictures for many years, but photography really only a hobby for me. Although, since I went digital my interest in photography has increased substantially. I mainly enjoy landscape photography, and my favourite location to take pictures is in the 1000 Island area of the St. Lawrence river, which is where my family and I vacation each year. I’ve attached two sample pictures: One was taken in the 1000 Islands, and the other is from my back yard.
1000 Island area of the St. Lawrence river
back yard
e4l: What programs do you use to manage and rework your photos? What platform do you use?
PH: I’m running Mac OS X. I have GIMP installed, but prefer the native OSX applications such as Photoshop and GraphicConverter for image manipulations. But I’m a minimalist when it comes to retouching photos – I usually find that I don’t want to change anything in my favourite pictures. But what I could use is a simple way (that produces professional looking results) of framing an image and adding a caption for poster-sized printing. I haven’t discovered an easy way to do this using the software I have now.
e4l: How come you started writing ExifTool?
PH: It evolved from a few routines I wrote for an image cataloguing utility that I wrote initially to maintain the images in the SNO web site in 2001. That was my introduction to Perl – before that I was mainly a C++ programmer.
Since then, I have done some rather substantial projects in Perl, and have really come to enjoy programming in this language. Now I find it hard to live without the automatic memory handling, hash lookups, and regular expressions.
e4l: Why do you write OpenSource software?
PH: I’ve always liked the idea of sharing free software, and started by writing freeware games back in the early 80’s. However, I didn’t release any open source software until 1994, when I wrote a utility to generate statistics from web server log files. Since then, I have made a few small applications public, but ExifTool represents my largest effort so far in the open source community.
e4l: ExifTool is a Perl library with a comand line tool as backend. On your homepage you write that this helps to envolve ExifTool that fast. Now, with 5.00 ready, can you imagine to port this to a c/c++-lib?
PH: When I decided to add the writing features to ExifTool last December, I considered rewriting the project in C++ since the work required to add the writing abilities would be many times the effort of writing the original utility. But even if I ignored the cost of rewriting the existing code, it would have been twice the work to do this project in C++, so I decided to use Perl.
e4l: libexif is a weak lib compared to your perl lib but used by every bigger project – GIMP and digiKam comes to my mind. When I showed ExifTool to the digiKam developer there was some scepsis about it because it is a perl lib.
Both GIMP and digiKam are searching for better metatag suport these days. Are you in contact with other projects that want to use ExifTool?
PH: Basically, it seems to be only the Perl programmers that are interested in ExifTool. People are using it in conjunction with their CGI scripts for web servers, or with Net::MovableType for photo blogs.
e4l: How can your perl lib be used from a c/c++ program?
PH: The only method I could think of is to exec Perl from within the C++ program, but that isn’t a very appealing solution.
e4l: Can you tell us more about the future of ExifTool, do you miss any function?
PH: Right now, it contains all of the major features that I had wanted to add. I’m sure I’ll add more features as other people make requests, but the future will certainly involve continued support for manufacturer-specific information as new cameras are released and people discover more about the information contained in their images.
e4l: Thanks for the interview and for ExifTool. Watching the development the last months and seeing the progress was fun. If you are in Germany maybe there is time for a jointly photo shooting :-)
PH: I’ll be sure to look you up! :)
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