Image encoding apparatus and method
A Joint Photographic Experts Group Extended Range (JPEG-XR) image encoding apparatus and method changes a quantized value or a coefficient prediction method for each block, thereby dramatically improving processing speed of the apparatus.
1. An image encoding apparatus comprising:
a scan converter for receiving a data block including a plurality of pieces of data set to correspond to pixel positions of a segmented image block, and scanning each piece of data in the received data block in a scan order represented in an order of a pixel position of the pieces of data;
a scan state holder for accumulating non-zero information of each piece of data in the received data block in accumulated non-zero information obtained by accumulating non-zero information of each piece of data in a previously received data block for each pixel position, and updating and holding the accumulated non-zero information for each pixel position; and
a scan order holder for searching for the updated accumulated non-zero information for every pixel position in the scan order, and when there is a part of the scan order where a value of the updated accumulated non-zero information is ascending, determining and holding a new scan order used in a following data block by replacing a scan order of two ascending pieces of accumulated non-zero information;
wherein a plurality of the scan converters are provided, in which a first scan converter is configured to receive a preceding data block and a second scan converter is configured to receive a following data block, the scan state holder sequentially updates accumulated non-zero information based on the preceding data block, and when the scan order holder partially determines a new scan order for a following data block based on a part of the updated accumulated non-zero information the scan state holder acquires data corresponding to a pixel position associated with the determined new scan order, from the following data block and updates accumulated non-zero information in the pixel position associated with the new scan order, and the scan order holder partially re-determines a new scan order for a following data block based on the updated accumulated non-zero information in the pixel position associated with the new scan order.
2. The image encoding apparatus of claim 1 , wherein the image encoding apparatus is applied to Joint Photographic Experts Group Extended Range (JPEG-XR) image encoding.
3. The image encoding apparatus of claim 1 , wherein the number of the scan converters corresponds to the number of pieces of data constituting a data block.
4. The image encoding apparatus of claim 1 , wherein when there is a part of the scan order where a value of the updated accumulated non-zero information is descending, the scan order holder determines and holds a new scan order used in a following data block by replacing a scan order of two descending pieces of accumulated non-zero information.
5. An image encoding method comprising:
a scan conversion step of receiving a data block including a plurality of pieces of data set to correspond to pixel positions of a segmented image block, and scanning each piece of data in the received data block in a scan order represented in an order of a pixel position of the pieces of data;
a scan state holding step of accumulating non-zero information of each piece of data in the received data block in accumulated non-zero information obtained by accumulating non-zero information of each piece of data in the previously received data block for each pixel position, and updating and holding the accumulated non-zero information for each pixel position; and
a scan order holding step of searching for the updated accumulated non-zero information for every pixel position in the scan order, and when there is a part of the scan order where a value of the updated accumulated non-zero information is ascending, determining and holding a new scan order used in a following data block by replacing a scan order of two pieces of ascending accumulated non-zero information;
wherein parallel scan conversion is performed, in which a preceding data block is received in a first scan conversion and a following data block is received in a second scan conversion; and
wherein accumulated non-zero information is sequentially updated based on the preceding data block, a new scan order for a following data block is partially determined based on a part of the updated accumulated non-zero information data corresponding to a pixel position associated with the determined new scan order is acquired from the following data block, accumulated non-zero information in the pixel position associated with the determined new scan order is updated, and a new scan order for a following data block is partially re-determined based on the updated accumulated non-zero information in the pixel position associated with the new scan order.
6. The image encoding method of claim 5 , wherein the image encoding method is applied to Joint Photographic Experts Group Extended Range (JPEG-XR) image encoding.
7. The image encoding method of claim 5 , wherein the number of the scan conversion processes corresponds to the number of pieces of data constituting a data block.
8. The image encoding method of claim 5 , wherein when there is a part of the scan order where a value of the updated accumulated non-zero information is descending, the scan order holder determines and holds a new scan order used in a following data block by replacing a scan order of two descending pieces of accumulated non-zero information.