adaptive background subtraction clarification in computer vision

[david-sullivan]

the text says "The overloaded operators for ofxCvImage make such running averages straightforward." however this only seems true for ofxCvFloatImage. If the background image is a type of ofxGrayscaleImage (or any other than floatImage), the example will not work.
my workaround, which may not be the best way, was:

`//convert grayImage and grayBg to ofxCvFloatImage versions, multiply then convert back to grayImage

    grayImageFloat = grayImage; //from ofxGrayscaleImage to ofxFloatImage
    grayBgFloat = grayBg;
    grayImageFloat *= 0.01;
    grayBgFloat *= 0.99;
    grayBgFloat += grayImageFloat;
    grayBg = grayBgFloat; // back to ofxGrayscaleImage`

[jhrtn]

I just ran into the same issue and your workaround helped me get through the last part of the chapter. It would be good to see a clarification in the docs what the best way to do this is