Archive for December, 2009
An alternative to bitmap transparency in Flash
Posted by Will | Filed under Adobe Flash, Adobe Flex, Banners, Experiments, Tutorials
When it comes to using transparent bitmap images in Flash often you will find using a PNG is your best option. However, a major caveat with using PNG images is the significant increase in file size compared to non-transparent image types such as JPEGs and (non-transparent) GIFs. This often becomes an issue when working on projects with limited allocated file size, such as banner ads.
A transparent PNG of the above image has a file size of approximately 109kB
Lately I’ve been toying with an alternative to PNGs… using JPEGs. “Wait a minute…”, you say, “JPEGs don’t support transparency!”. That’s correct but by making use of Flash’s BitmapData class we can merge two non-transparent images together to make a single transparent image. Even though this method actually requires 2 separate JPEGs the total combined file size is almost always significantly smaller than a single PNG! (more…)
