tried to search for this but both ofxCvGrayscaleImage and brightnessContrast are too long for the restrictions
Getting an error when trying to use this in of_preRelease_v0061_osxSL_FAT/opencvExample. I just added this
// take the abs value of the difference between background and incoming and then threshold:
grayDiff.brightnessContrast(10, 10);