A luminance correcting system for an organic light emitting display includes an image analyzing unit for analyzing an image on a display unit and for measuring luminance and color coordinates of reference gray level data, a reference offset value setting unit for setting reference offset values of respective color data in the reference gray level data to correspond to an image analysis result obtained by the image analyzing unit, a controller for detecting a difference in reference offset values of at least two color data among the respective color data in the reference gray level data and for comparing the difference with a reference value, and an additional offset value setting unit for setting an additional offset value corresponding to at least one gray level among gray level data excluding the reference gray level data when the difference in the reference offset values is not less than the reference value.
展开▼