Image processing device and image processing method that horizontal filtering on pixel blocks

An image processing method comprising:

• performing with circuitry horizontal filtering determination processes across a plurality of vertical block boundaries among a plurality of blocks within a locally decoded image, each horizontal filtering determination process determines whether to apply a horizontal filter to pixels neighboring a respective vertical block boundary;
• applying, in parallel, the horizontal filter to the pixels that neighbor the plurality of vertical block boundaries within the image to which the horizontal filter is determined to be applied by the horizontal filtering determination processes to generate a first filtered image, the horizontal filter being applied to each of the plurality of vertical boundaries within the image to which the horizontal filter is determined to be applied by the horizontal filtering determination processes without depending on horizontal filter results of the other vertical block boundaries of the plurality of blocks to which the horizontal filter is determined to be applied;
• performing with the circuitry vertical filtering determination processes across a plurality of horizontal block boundaries among the plurality of blocks within the first filtered image, each vertical filtering determination process determines whether to apply a vertical filter to pixels that neighbor a respective horizontal block boundary;
• applying, in parallel, the vertical filter to the pixels that neighbor the horizontal block boundaries within the first filtered image generated by the horizontal filtering to which the vertical filter is determined to be applied by the vertical filtering determination processes to generate a second filtered image, the vertical filter being applied to each of the plurality of horizontal boundaries within the first filtered image to which the vertical filter is determined to be applied without depending on vertical filter results for the other horizontal block boundaries of the plurality of blocks to which the vertical filter is determined to be applied;
• and
• encoding an image using the second filtered image.