Visible emission images digitized by Image Processor were applicated in two ways. First, the intensity of visible emission from blackbody cavity obtained by CCD array camera was converted into temperature by broadband pyrometry analysis using the theoretical background of effective wavelength method. The calculated cavity temperature agreed with thermocouple measured temperature within 1% error range. Second, by introducing the concept of intensity field, flame monitoring system using quantitative visible emission image was developed, and the pseudo-coloring technique was applied for enhancement of discrimination. And the system can be expected to promote the conventional system in acquiring, analyzing, and storing the image of flame.