1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method, and a computer program.
2. Description of the Related Art
RAW data output from a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) used as an imaging element of a digital camera includes various noises. As a method of effectively removing noises, there is a method which changes a noise removal strength in consideration of a human visual feature (for example, see Japanese Unexamined Patent Application Publication No. 2004-151907).
For example, in the case where an image is developed by converting RAW data into signals of different formats, it is necessary to effectively remove noises included in the converted signals. For example, in the case where the RAW data is converted into image data (for example, YCC data) including a luminance signal and a color difference signal, a noise of an image is classified into a luminance noise and a color noise. In addition, a method is widely used which is capable of improving image quality by removing the color noise.
In the past, in order to remove the color noise, after obtaining the image data including the luminance signal and the color difference signal through the conversion, a noise reduction process is performed on the color difference signal so as to remove a noise therefrom. When such a noise reduction process is performed, it is possible to remove only the color noise while using the current luminance signal.