blur things easily! Render your scene into the ofxFboBlur object; it will keep your original scene, and a blurred copy of it. This way, you can draw your "clean" scene and overlay any amount of blur you want on top of it.
//choose your fbo settings
ofFbo::Settings s;
s.width = ofGetWidth();
s.height = ofGetHeight();
s.internalformat = GL_RGBA;
s.maxFilter = GL_LINEAR; GL_NEAREST;
s.numSamples = 4;
s.numColorbuffers = 3;
s.useDepth = true;
s.useStencil = false;
//setup thing
gpuBlur.setup(s);
//tweak your blurring
gpuBlur.blurOffset = 5 * ofMap(mouseY, 0, ofGetHeight(), 1, 0, true);
gpuBlur.blurPasses = 10. * ofMap(mouseX, 0, ofGetWidth(), 0, 1, true);
gpuBlur.numBlurOverlays = 1;
gpuBlur.blurOverlayGain = 255;
//draw your scene in the fbo, no drawing on screen yet
gpuBlur.beginDrawScene();
//YOUR STUFF HERE!
gpuBlur.endDrawScene();
//calc the fbo blurring, no drawing on screen yet
gpuBlur.performBlur();
//draw the "clean" scene on screen
ofEnableBlendMode(OF_BLENDMODE_ALPHA);
gpuBlur.drawSceneFBO();
//overlay the blurred fbo on top of the previously drawn clean scene
ofEnableBlendMode(OF_BLENDMODE_ADD);
gpuBlur.drawBlurFbo();