... Basic algorithms for the production of stellar photometry from CCD observations are described and reviewed. ... The problem of doing accurate stellar photometry with calibrated charge-coupled device (CCD) data amounts to that of condensing the intensity values of hundreds, thousands, or even millions of picture elements (pixels) into a list containing the magnitude and position of each star on the CCD image. ... Center an aperture of N A pixels on the star. ... PIXEL.LT.PEAKMAX)) THEN BINGO = .TRUE....