Action Script3 / Pixel Bender Compound Blur effect?

Question

I need Action Script3 / Pixel Bender blur filter with mapping capability’s.

We have such image, we want to apply such blur map to get such result

alt text http://livedocs.adobe.com/en_US/AfterEffects/8.0/images/ef_182.png

Its also known as Compound Blur effect.

Has anyone seen it done with AS3/ Pixel Bender?

Does Anyone know where to download such effect with source?

Answer 1

The following .pbk should pretty much do it. You can take a look at the comments to see how you would deepen the blur effect.

<languageVersion : 1.0;>
kernel NewFilter
<   namespace : "Your Namespace";
    vendor : "Your Vendor";
    version : 1;
    description : "your description";
>
{
    input image4 src1;
    input image4 src2;
    output pixel4 dst;

    void
    evaluatePixel()
    {
        float2 pos = outCoord();

        // based on the current whiteness of pixel in src2 blur by a percentage.
        float4 val = sampleNearest(src2,pos);
        float percent = val[0];

        // this takes into account only the closest level of pixels to make the blur more in depth 
        // you can add the next 16 or even the 24 after that. 
        float4 pix = sampleNearest(src1,pos);
        float4 pixNE = sampleNearest(src1,float2(pos.x+1.0, pos.y+1.0));
        float4 pixE = sampleNearest(src1,float2(pos.x+1.0, pos.y));
        float4 pixSE = sampleNearest(src1,float2(pos.x+1.0, pos.y-1.0));
        float4 pixS = sampleNearest(src1,float2(pos.x, pos.y-1.0));
        float4 pixSW = sampleNearest(src1,float2(pos.x-1.0, pos.y-1.0));
        float4 pixW = sampleNearest(src1,float2(pos.x-1.0, pos.y));
        float4 pixNW = sampleNearest(src1,float2(pos.x-1.0, pos.y+1.0));
        float4 pixN = sampleNearest(src1,float2(pos.x, pos.y+1.0));

        float4 result;
        // the result is the whiteness percentage of the original pixel averaged with the surrounding pixels.
        // if you added more of the surrounding pixels you can consider them in the weighted average also and get a deeper blur.
        result[0] = percent*pix[0]+(1.0-percent)*(pixNE[0]+pixE[0]+pixSE[0]+pixS[0]+pixSW[0]+pixW[0]+pixNW[0]+pixN[0])/8.0;
        result[1] = percent*pix[1]+(1.0-percent)*(pixNE[1]+pixE[1]+pixSE[1]+pixS[1]+pixSW[1]+pixW[1]+pixNW[1]+pixN[1])/8.0;
        result[2] = percent*pix[2]+(1.0-percent)*(pixNE[2]+pixE[2]+pixSE[2]+pixS[2]+pixSW[2]+pixW[2]+pixNW[2]+pixN[2])/8.0;
        result[3] = pix[3];

        dst = result;
    }
}