Power-constrained　image　contrast　enhancement　is　a　fundamental　step　for　improving　the　battery　life　in　many　modern　consumer　devices　embedded　an　emissive-display　panel,　such　as　organic　light　emitting　diode.　Conventional　power-constrained　image　contrast　enhancement　approaches　in　OLED　displays　are　usually　performed　by　histogram-relevant　priors　or　heuristic　curve-fitted　techniques.　Often,　this　results　in　either　underexposure　effects　or　color　tone　changes　in　the　enhanced　image.　Different　from　the　existing　approaches,　this　paper　proposes　a　novel　power-constrained　sparse　representation　model　by　joint　l2,1-norm　regularized　sparse　coding　in　order　for　gaining　in　power-saving　and　perceptible　visual-quality　on　OLED　display,　simultaneously.　Experiments　on　both　quantitative　and　qualitative　evaluations　demonstrate　that　the　proposed　PCSR　approach　noticeably　outperforms　the　state-of-the-art　power-constrained　contrast-enhancement　approaches.