Method for processing image data

A method for processing image data adapted to an image data processing apparatus comprising a writing controller, a reading controller, a buffer and a state controller wherein the buffer comprises a first buffer area and a second buffer area, the method comprising the steps of:

• (a) horizontally writing the image data into the first buffer area by the writing controller until the first buffer area is fully written;
• (b) vertically reading the image data stored in the first buffer area by the reading controller and synchronously and horizontally writing the image data into the second buffer area by the writing controller;
• (c) while completely reading a first portion of the first buffer area by the reading controller, allocating the complete read the first portion of the first buffer area into the second buffer area by the state controller;
• (d) vertically reading the image data in a second portion of the first buffer area by the reading controller and writing the image data into the second buffer area by the writing controller;
• (e) while the state controller determines that the writing controller completely writes the second buffer area, vertically reading the image data of second buffer area by the reading controller and horizontally writing the image data into the first buffer area by the writing controller, and after completely reading a portion of the second buffer area by the reading controller, allocating the read portion of the second buffer area into the first buffer area by the state controller;
• and
• (f) repeating the steps of (a) through (e) to complete the access of the image data.