I came across a funny thing the other while trying to add images to my flash project. I needed to preload and show jpeg images dynamically for a flash based homepage, intended for a newspaper company in the netherlands.

The funny thing was, the jpeg images wouldn’t show up :S. At first i figured their might be something wrong with my load functions, but because there were no error messages it seemed kind of odd. I used multiple methods for loading the images, including the newer types of preloading which are implemented since flash 7.0.

No matter how hard i tried, screemed, yelled, banged my head into the walls….. the images wouldn’t show up.

After quite a few caffeine overdosed hours of searching for the problem… it finally hit me…… The images provided by the clients where saved in the jpeg format, but they used an option called ‘progressive jpg’. It seems that flash cannot handle the loading of such images.

The Macromedia Flash Player does not have a decompressor for progressive JPEG images, therefore files of this type cannot be loaded dynamically and will not display when using the loadMovie action.

The people who have seen the beginning of the internet might remember the wow-factor of adding images to a text-based web page. (a real web site was kind of rare those days). The problem then was, that people needed to squeeze those images through their 14k4 modems, which could take forever if the ‘webmaster’ was a big fan of multiple colourfull and joyfull images on his webpage.

That’s where the ‘progressive’ jpg came in. It split the jpg information in multiple layers kind of thingies, so that the viewers could watch the picture build up while downloading it, instead of having to wait for the whole thing.

A progressive JPEG is the JPEG equivalent of the interlaced GIF Graphics Interchange Format. It’s an image created using the JPEG suite of compression algorithms that will “fade in” in successive waves of lines until the entire image has completely arrived. Like the interlaced GIF, a progressive JPEG is a more appealing way to deliver an image at modem connection speeds. Users with faster connections are not likely to notice the difference.

The only solution for this problem is to resave the image in an picture editor program (e.g. Photoshop or Paint Shop Pro) and make sure you leave anything ‘progressive’ related off.

Just for a little bit of reminder, here are the the file types which are supported by at least Macromedia Flash MX [1]:

¹ you can review this list including an explanation at macromedia

Although you might be turned off by the looks of this website at first, you will discover how great and funny the whole thing is setup as soon as you take some time to look into it.

Cartoonsmart.com is a great site for people looking for tutorials in a lot of basic aspects of flash. The toonish way in which the grapics are drawn, made me bow in respect a couple of times. Very funny indeed.

A large portion of the video tutorials are hidden behind a payed section, but even for free viewers, a lot of interesting stuff can be found.

Great use of flash in this site, big compliments…

Been a while since my last post. French riviera took all of my free time ;) Let me return with a rather interesting post of a developed Rich Internet App i did just before me leaving.

The app is called ‘Watermanager’ and is a flash ‘RIA’ conversion of an existing desktop application. It’s intention is to let visitors view the current state of the rivers in the Netherlands and examin the effects on the water levels when they turn certain ‘measures’ on and off.

The Watermanager was my first real project developing RIA’s. It was a major challenge because it’s functional specification was kind of a big deal. The existing desktop application had some nice features in it, which where challenging to fit into a Flash interface.

I also tried out Macromedia Flash Professional’s project management functions in this project. Although they could use some tweaking, they did do their job correctly. I used an interface to Microsoft SourceSafe for maintaining script files and version controls. No problems there. You might want to try certain project management functionality out for yourself. They have the potential to safe you some headaches if you loose a file or two.

A few components where used in the application. e.g. the datagrid component which was a breeze to use. Just follow the instructions and it should work out fine. I linked the datagrid component to an xml datasource through AS. I still am surprised by the speed of flash 2004 when parsing xml files btw. Every time you click on the interface of the watermanager, a xml request is being send to the server. And a whole new xml tree is being parsed. A 10k xml file takes less then a second to convert into interface information.

Take a look into the app if you like. Any feedback is more then welcome.