1. A method of processing a mosaicked image, comprising: up-sampling the mosaicked image along a direction to generate a group of pixel data; and resizing the group of pixel data along the direction to generate an image comprising at least one full-sampled color plane and at least one sub-sampled color plane; wherein odd lines along the direction in a first color plane of the mosaicked image are sub-sampled, even lines along the direction in a second color plane of the mosaicked image are sub-sampled, and all lines along the direction in a third color plane of the mosaicked image are sub-sampled, and the step of up-sampling the mosaicked image along the direction to generate the group of pixel data comprises: converting the odd lines along the direction in the first color plane into full-sampled lines; converting the even lines along the direction in the second color plane into full-sampled lines; and converting all the lines along the direction in the third color plane into full-sampled lines.