1. Technical Field
The present invention is directed to a device and method for removing grid noises, more specifically to a device and method for removing grid noises in an image processing system.
2. Description of the Related Art
It is common that grid noises occur during a color interpolation process in a Bayer pattern image inputted to an image processing system, due to a difference in line values of Gr (reddish green) and Gb (bluish green). This is described below with reference to the accompanying drawing.
FIG. 1 shows an example of average values of green pixels of a typical Bayer pattern image in the horizontal direction.
It can be seen in the drawing that there are substantial differences in average values of green pixels in the horizontal direction between even lines and odd lines. These differences cause grid noises through color interpolation, as shown in FIG. 2, which shows an example of grid noises occurred by color interpolation in a conventional image processing system.
A gaussian filter or a median filter has been conventionally used in order to remove these noises. Although these filters were able to remove the grid noises, they also damaged image details (e.g. the high-frequency edge or boundary). In other words, it has been practically impossible for the method of removing grid noises by use of a conventional filter to remove the grid noises while preserving the image details.