Paul Robertson's words, punctuated

Thoughts on development, user-centered design, code, etc. by Paul Robertson

ActionScript BitmapData and Filters resources

Personally I ran into two big stumbling blocks as I was trying to get my head around the new bitmap manipulation capabilites in Flash 8, particularly the ones in the BitmapData class and the more “low-level” filters (like DisplacementMapFilter and ConvolutionFilter). First of all, I wasn’t sure exactly what the filters could be used for. What sorts of effects would you create using a convolution filter? When would I choose to use a displacement map? Second, there are a lot of concepts that you need to understand to work with bitmap data manipulation, and frankly I hadn’t had occasion to do that sort of programming before.

So, I dug in and started spending a lot of time studying these concepts and looking for inspiration. Through all of that I found lots of articles and sites that I felt were good resources. A word of warning – none of these sites talk specifically about how to implement the concepts or effects in ActionScript. Those that do provide code usually provide it in other languages, and several of them don’t give any code at all – they are sites that show examples of the type of effects that can be created using particular filters.

In summary, if you’re looking for an easy tutorial, this isn’t the list for you, but if you want to get a better grounding in the conceptual underpinnings and possible applications of the BitmapData and filters classes in Flash/ActionScript, here is a list of great resources:

Note: I have listed a source when the article was recommended by someone else; otherwise, the source is our friend Google.

Graphics programming concepts

Blending modes

Perlin noise


Displacement Map

Color Transformation

BitmapData - specific effects