An image processing device including a decoding section configured to decode an image from an encoded stream, a horizontal filtering section configured to apply a deblocking filter to a vertical block boundary within an image to be decoded by the decoding section, a vertical filtering section configured to apply a deblocking filter to a horizontal block boundary within an image to be decoded by the decoding section, and a control section configured to cause the horizontal filtering section to filter in parallel a plurality of vertical block boundaries included in a processing unit containing a plurality of coding units and cause the vertical filtering section to filter in parallel a plurality of horizontal block boundaries included in the processing unit.