An apparatus for processing a digital image and storing the processed digital image, comprising: an image sensor configured to sense (S10, S20, S120) a hand-drawn sketch (111, 113) and convert the sensed hand-drawn sketch (111, 113) to a digital image, wherein the hand-drawn sketch (111, 113) corresponds to a sketch being expressed with a liquid or solid substance a storage unit configured to store (S10, S30, S140) the converted digital image; an image display unit configured to display (S20, S150) the stored digital image as a virtual hand-drawn sketch; and a controller configured to control the image sensor, the storage unit and the image display unit, wherein the controller is further configured to: sense (S10, S120) a first hand-drawn sketch having first sketching characteristics; store (S10, S140) the sensed first hand-drawn sketch as a first digital image; display (S20, S140) the stored first digital image as a first virtual hand-drawn sketch; sense (S30, S120) a second hand-drawn sketch being additionally drawn on the displayed first virtual hand-drawn sketch, the second hand-drawn sketch having second sketching characteristics; characterized in that the controller is further configured to: change the second sketching characteristics of the sensed second hand-drawn sketch to the first sketching characteristics of the stored first digital image; and store (S30, S140) the sensed second hand-drawn sketch as a second digital image with the changed second sketching characteristics. an image sensor configured to sense (S10, S20, S120) a hand-drawn sketch (111, 113) and convert the sensed hand-drawn sketch (111, 113) to a digital image, wherein the hand-drawn sketch (111, 113) corresponds to a sketch being expressed with a liquid or solid substance a storage unit configured to store (S10, S30, S140) the converted digital image; an image display unit configured to display (S20, S150) the stored digital image as a virtual hand-drawn sketch; and a controller configured to control the image sensor, the storage unit and the image display unit, wherein the controller is further configured to: sense (S10, S120) a first hand-drawn sketch having first sketching characteristics; store (S10, S140) the sensed first hand-drawn sketch as a first digital image; display (S20, S140) the stored first digital image as a first virtual hand-drawn sketch; sense (S30, S120) a second hand-drawn sketch being additionally drawn on the displayed first virtual hand-drawn sketch, the second hand-drawn sketch having second sketching characteristics; characterized in that the controller is further configured to: change the second sketching characteristics of the sensed second hand-drawn sketch to the first sketching characteristics of the stored first digital image; and store (S30, S140) the sensed second hand-drawn sketch as a second digital image with the changed second sketching characteristics. sense (S10, S120) a first hand-drawn sketch having first sketching characteristics; store (S10, S140) the sensed first hand-drawn sketch as a first digital image; display (S20, S140) the stored first digital image as a first virtual hand-drawn sketch; sense (S30, S120) a second hand-drawn sketch being additionally drawn on the displayed first virtual hand-drawn sketch, the second hand-drawn sketch having second sketching characteristics; characterized in that the controller is further configured to: change the second sketching characteristics of the sensed second hand-drawn sketch to the first sketching characteristics of the stored first digital image; and store (S30, S140) the sensed second hand-drawn sketch as a second digital image with the changed second sketching characteristics. change the second sketching characteristics of the sensed second hand-drawn sketch to the first sketching characteristics of the stored first digital image; and store (S30, S140) the sensed second hand-drawn sketch as a second digital image with the changed second sketching characteristics.