1. An image processing method applied in an electronic device comprising an input module, an image sensor module, an image processor and an image coding module, comprising the following steps of: receiving a user input from the input module for launching an image application; initializing the image sensor module in response to the user input; capturing at least one first image frame by the image sensor module upon the image sensor module turning to a first state during the initialization; processing the first image frame by the image processor; storing the first image frame processed by the image processor in a first buffer; receiving an image operation input from the input module; and encoding the first image frame stored in the first buffer by the image coding module in response to the image operation input.