Effective

Effective pixels - Though your digicam may claim to have 3.34 million pixels on it's CCD, some of the pixels will not be used for taking pictures. Usually those around the edge of the sensor are painted black to provide a colour balance, while others fall outside the range of the lens. Effective pixels are the ones actually used to capture the image. If the effective figure is larger than the total figure the camera interpolates or makes up, the rest of the pixels are taken from information from the original pixels.