Customer Reviews

Programming Web Graphics with Perl & GNU Software (O'Reilly Nutshell)

5 star:		(9)
4 star:		(1)
3 star:		(2)
2 star:		(2)
1 star:		(1)

 

 

This is not an art book. There are not even any color illustrations. Rather, there is uniquely definitive and comprehensive coverage of the most important freeware graphics tools useful for web development. There is a strong bias toward programmatic tools, those which can be controlled from server-parsed HTML or CGI using Perl, which allow drawing graphics interactively with the user on the fly. One example with source code is a Perl "biorhythm" calculator, where the user enters a birthdate and the web page draws a customized GIF bar chart with a sinusoidal envelope, emulating the coin-operated "biorhythm" machine at the Vince Lombardi Rest Area on I-95 in New Jersey. This basic technique can be used for charts of stock performance, server activity, and any other on-demand drawing. The ImageMagick tool, which can be run from a command line to do batch processing (such as thumbnailing) or through a Perl API, is also well covered, showing how to draw text labels onto images and do other tasks essential to good web practice. The GIMP, a web-friendly freeware clone of Adobe Photoshop, is covered primarily from the point of view of its relatively unknown Perl API, but this is not a book about the GIMP and there are better choices of books (especially those with color) if interactive use of the GIMP is your main concern. However, use of the GIMP to create basic web elements such as flaming marbles or imploding cats is covered. This book stands in a class by itself on its subject matter, and is destined to become one of the classic O'Reilly references. While it does have copious pointers to web information via URLs, the book's most serious deficiency is certainly that it is heavily tied to the current snapshot of available tools, and the freeware tool development pace will doubtlessly necessitate frequent revisions of this book, possibly as often as annually. The author is also to be commended for not flinching from discussions of technical issues where appropriate, such as image compression, interlacing, and the internals of GIF, JPEG, and PNG file formats, but these discussions are not essential to the book if the reader has little interest in technical issues and wants to get right to the cookbook graphics recipes.

It's a reasonable start if you want to work with GD, ImageMagick and others, but it's too much a printed version of the manpages. With examples and some tips though. It also adresses GIMP but fails to provide indept info on scripting GIMP.

I don't know about the rest of you, but I can only stand to grab data out of a text file so many times... I have never done graphics programming before and found this book to be a nice introduction. I did notice that there wasn't a lot of troubleshooting information in the book so if you are experienced programming graphics, this book is probably a waste of your time and $$$, you would be better off busting out your lazerjet and printing the man pages...

Anyway, I really enjoyed this book and plan on using ImageMagick in my next project!

If you want something thats a slight change of pace, give this a try!

This book offers nothing but the documentation found at the CPAN website. They dont even go as far as to suggest any use (other than the obvious) for any function. So, I will give you one: When printing a string in an image, do @bounds=GD::Image->stringTTF(...) first. It will give you the string dimensions without actually graphing the string. You can then use the bounds array to see what the width and size of the string is so that you can center it. Want to know what the bounds array holds? Spend the money for the book, or go look it up at CPAN.org for free. Oh, by the way, this book does not even tell you that you can call stringTTF as a package subroutine, let alone the numerous reasons why you would want to use it as such.... Like I said - save your money.

I have no other option but accepting most of the negative reviews submitted to this book ( Graphics Programming with Perl and GNU software ). The book is definitely one of the horrible books that O'reilly was ever unfortunate enough to publish. I believe a similar title by "Manning" publication does a better job than this one. If you need the facts, read on.

If you want to purchase this book to learn how to program web graphics with Perl, stop right here and go to CPAN.org. Search for GD, GD::Graph and ImageMagick and read their manuals. That's all this book does any ways.

The only chapter I enjoyed was chapter one, "Image File Formats", which at least taught me something I hadn't known before.

Outlines of the chapters follow.

Chapter one - "Image File Formats" covers most of the basics you need to know to understand the anatomy of graphics, their compression algorithms and different formats available for the web, as well as their pros and cons. This is the chapter I enjoyed most. The chapter lasts over 30 pages.

Chapter two - "Serving graphics on the Web" talks a bit about serving images from within Perl. Talks how the browser loads the images, image load time and image caching. Shows the <IMG> tag, and its attributes. Lasts another 30 pages.

Chapter 3 - "A Litany of Libraries" lists references to some of the graphics libraries available on the web. I would expect to see this chapter as an appendix.

Starting chapter 4 - "On-the-Fly graphics with GD" is the start of all the disappointment, and to some extent, annoyance. After a clumsy introduction to GD and some of its classes and methods, starts coding a chess board. The application itself is not so useful, but the code is worth consideration. The chapter also lists all the methods available through GD classes with some description of each.

Chapter 5, 6 and 7 are written in the same style as the above sibling. They concentrate on Image::Magic (also known as PerlMagick), GD::Graph (previously known as GIFgraph ) and Gimp respectively. Chapter 7 teaches how to write Gimp Plug-ins. You might consider this chapter if you're a Gimp user/fan.

This book is exacly what you need for creating dynamic webpages. It covers everything from file types to advanced image manuipulation functions. This book is well written so it is easy to understand even if you aren't familiar with PERL yet. I sincerely recommend it if you are going to create graphics on the web.

Although the subject matter is great, it lacks a lot when it comes to substance. It is very sad when you have to trouble shoot the example source code from a book that was written to teach you. I am only halfway through the book and the two of example scripts failed do to coding problems with the modules.
The Biorhythm example fails even when you copy it from the author's web site. If you are going to write a book proof your code.

I can only use an example to show how inspirational I've found this book. A Sys Admin and I were sipping cold beer in early Spring sunshine, on a Monday lunchtime. As we're both old gits, we got to talking about Veritas disk mappings and how difficult they can be to visualise (yes, I know just how sad this is). How about a web page? he asked. I was at a loose end, so I agreed to take a look. With this book's enthusiastic help and superb encouragement, by Friday in the Pub, we had a fully working intranet site which could deliver complete dynamic charted disk mappings of every machine on our entire network. Easily printed from Netscape, this single CGI/GIFgraph web tool now delivers clear condensed disk map charts in full "browser-safe" colour onto standard printer paper, displaying both mirrored volumes and all the other gubbins a tortured soul could require. This will save our Sys Admin teams hundreds of hours of tedium in the next few months, as we rebuild all of our machines. And that was only Chapter 6. This week I'll be reading Chapter 7 on the Gimp, and already I've realised whatever Adobe may like to quote me in the future for a Photoshop licence, I'm never going to have to pay it. Another brick in the wall of the propriertary monolith comes tumbling down. Rejoice.

For those of you who know just about all there is to know about CGI using Perl, buy this book! This book introduced me to a side of Perl I had never thought of before.I just began writing custom system monitoring applications using Perl and the knowledge of the GIFgraph and GD modules gained from this book. It's well written and has relatively few technical errors (what O'Reilly book has many errors?). If you know Perl, you know the O'Reilly name is synonymous with excellence. This book is no exception.

Amazing, you really dont even need to know Perl, (though it helps:) Definitly buy it if you want to generate PNG, JPEG, and GIFs ON THE SEVER. A MUST HAVE!