A data processing apparatus for processing image data includes a variance
information calculator configured to calculate variance information
indicating the degree of variance of pixel values for each of a plurality
of pixels constituting the image data; a smoothing section configured to
smooth the variance information and to output a smoothed value; a
determination section configured to determine an area to which the pixel
belongs on the basis of the smoothed value and to output area information
indicating the area; a parameter determination section configured to
determine a parameter for a noise removal process for each of the pixels
constituting the image data on the basis of the area information and the
smoothed value; and a noise removal section configured to perform the
noise removal process on the image data on the basis of the parameter
determined for each of the pixels.