Resolution detecting circuit and method thereof

An apparatus (10) and a related method for automatically detecting the resolution of an image signal (IS) and for adjusting the input images to the native resolution of a display device are disclosed. The resolution mode detection apparatus (10) comprises a front-end circuit (11), a back-end circuit (12) and a determining unit (13). In the front-end circuit, a measuring unit (111 ) measures parameters (IF) of the input image signal (IS). A mode detecting unit (112) selects one out of a plurality of resolution modes based on the parameters (IF) and creates synchronization signals (HSi,VSi) used by a data fetching unit (113) for sampling the image signal. In the back-end circuit (12), the image samples (IS') are stored in a line buffer (121) and are scaled (122) to the display device's native resolution. A determining unit (13) detects abnormal conditions (FB) like buffer underflows or overflows and generates a control signal (DT) to correct the selected resolution mode accordingly.