Electronic device and method for splitting image

1. A method for splitting an image using an electronic device, the method comprising:

obtaining a largest coding unit (LCU) of the image, and dividing the LCU into a plurality of 2N×2N blocks;

calculating a pixel variance and an average value of pixels of each of the 2N×2N blocks;

obtaining a current 2N×2N block from the LCU according to a recursive order, determining whether the current 2N×2N block needs to be split according to the pixel variance of the current 2N×2N block;

splitting the current 2N×2N block into four N×N blocks upon the condition that the current 2N×2N block needs to be split; and

determining, using a processor, to whether a block merging operation needs to be executed for the LCU according to the average value of pixels of each of the 2N×2N blocks upon the condition that the current 2N×2N block does not need to be split, and executing the block merging operation when the block merging operation is needed.

2. The method according to claim 1 , wherein determining whether the current 2N×2N block needs to be split is performed by:

determining that the current 2N×2N block needs to be split upon the condition that the pixel variance of the current 2N×2N block is greater than or equal to a threshold value; or determining that the current 2N×2N block does not need to be split upon the condition that the pixel variance of the current 2N×2N block is less than the threshold value.

3. The method according to claim 1 , wherein the block merging operation comprising a first merging of 2N×2N block, the first merging of 2N×2N block is executed by:

determining whether the current 2N×2N block is the last block of a current 4N×4N block;

determining whether the current 4N×4N block comprises N×N block upon the condition that the current 2N×2N block is the last block of the current 4N×4N block;

determining whether the average values of pixels of four 2N×2N blocks in the current 4N×4N block are similar upon the condition that the current 4N×4N block does not comprise N×N block;

executing the first merging by merging the four 2N×2N blocks in the current 4N×4N block into one block upon the condition that the average values of pixels of the four 2N×2N blocks in the current 4N×4N block are similar.

4. The method according to claim 3 , wherein the average values of pixels of the four 2N×2N blocks in the current 4N×4N block are determined to be similar upon the condition that a deviation of the average values of pixels between every two 2N×2N blocks of the current 4N×4N block is less than a preset value.

5. The method according to claim 3 , wherein the first merging of 2N×2N block is executed by:

determining that the block merging operation is ended upon the condition that the current 4N×4N block comprises N×N block or that the average values of pixels of the four 2N×2N blocks in the current 4N×4N block are not similar.

6. The method according to claim 3 , wherein the first merging of 2N×2N block is executed by:

determining whether a second merging of 4N×4N block is needed upon the condition that the current 4N×4N block comprises N×N block, or that the average values of pixels of the four 2N×2N blocks in the current 4N×4N block are not similar, or that the first merging is executed.

7. The method according to claim 6 , wherein the second merging of 4N×4N block is executed by:

determining whether the current 2N×2N block is the last block of a current 8N×8N block;

determining whether the current 8N×8N block comprises blocks less than 4N×4N upon the condition that the current 2N×2N block is the last block of the current 8N×8N block;

determining whether the average values of pixels of four 4N×4N blocks in the current 8N×8N block are similar upon the condition that the current 8N×8N block does not comprise blocks less than 4N×4N block;

executing the second merging by merging the four 4N×4N blocks in the current 8N×8N block into one block upon the condition that the average values of pixels of the four 4N×4N blocks in the current 8N×8N block are similar.

8. An electronic device, comprising:

a processor;

a storage device storing a plurality of instructions, which when executed by the processor, causes the processor to:

obtain a largest coding unit (LCU) of an image, and divide the LCU into a plurality of 2N×2N blocks;

calculate a pixel variance and an average value of pixels of each of the 2N×2N blocks;

obtain a current 2N×2N block from the LCU according to a recursive order, determine whether the current 2N×2N block needs to be split according to the pixel variance of the current 2N×2N block;

split the current 2N×2N block into four N×N blocks upon the condition that the current 2N×2N block needs to be split; and

determine whether a block merging operation needs to be executed for the LCU according to the average value of pixels of each of the 2N×2N blocks upon the condition that the current 2N×2N block does not need to be split, and execute the block merging operation when the block merging operation is needed.

9. The electronic device according to claim 8 , wherein determining whether the current 2N×2N block needs to be split is performed by:

determining that the current 2N×2N block needs to be split upon the condition that the pixel variance of the current 2N×2N block is greater than or equal to a threshold value; or

determining that the current 2N×2N block does not need to be split upon the condition that the pixel variance of the current 2N×2N block is less than the threshold value.

10. The electronic device according to claim 8 , wherein the block merging operation comprising a first merging of 2N×2N block, the first merging of 2N×2N block comprising steps of:

determining whether the current 2N×2N block is the last block of a current 4N×4N block;

determining whether the current 4N×4N block comprises N×N block upon the condition that the current 2N×2N block is the last block of the current 4N×4N block;

determining whether the average values of pixels of four 2N×2N blocks in the current 4N×4N block are similar upon the condition that the current 4N×4N block does not comprise N×N block;

executing the first merging by merging the four 2N×2N blocks in the current 4N×4N block into one block upon the condition that the average values of pixels of the four 2N×2N blocks in the current 4N×4N block are similar.

11. The electronic device according to claim 10 , wherein the average values of pixels of the four 2N×2N blocks in the current 4N×4N block are determined to be similar upon the condition that a deviation of the average values of pixels between every two 2N×2N blocks of the current 4N×4N block is less than a preset value.

12. The electronic device according to claim 10 , wherein the first merging of 2N×2N block is executed by:

determining that the block merging operation is ended upon the condition that the current 4N×4N block comprises N×N block or that the average values of pixels of the four 2N×2N blocks in the current 4N×4N block are not similar.

13. The electronic device according to claim 10 , wherein the first merging of 2N×2N block is executed by:

determining whether a second merging of 4N×4N block is needed upon the condition that the current 4N×4N block comprises N×N block, or that the average values of pixels of four 2N×2N blocks in the current 4N×4N block are similar, or that the first merging is executed.

14. The electronic device according to claim 13 , wherein the second merging of 4N×4N block is executed by:

determining whether the current 2N×2N block is the last block of a current 8N×8N block;

determining whether the current 8N×8N block comprises blocks less than 4N×4N upon the condition that the current 2N×2N block is the last block of the current 8N×8N block;

determining whether the average values of pixels of four 4N×4N blocks in the current 8N×8N block are similar upon the condition that the current 8N×8N block does not comprise blocks less than 4N×4N block;

executing the second merging by merging the four 4N×4N blocks in the current 8N×8N block into one block upon the condition that the average values of pixels of the four 4N×4N blocks in the current 8N×8N block are similar.

15. A non-transitory storage medium having stored thereon instructions that, when executed by a processor of an electronic device, causes the electronic device to perform a method for splitting an image, the method comprising:

obtaining a largest coding unit (LCU) of the image, and dividing the LCU into a plurality of 2N×2N blocks;

calculating a pixel variance and an average value of pixels of each of the 2N×2N blocks;

obtaining a current 2N×2N block from the LCU according to a recursive order, determining whether the current 2N×2N block needs to be split according to the pixel variance of the current 2N×2N block;

splitting the current 2N×2N block into four N×N blocks upon the condition that the current 2N×2N block needs to be split; and

determining whether a block merging operation needs to be executed for the LCU according to the average value of pixels of each of the 2N×2N blocks upon the condition that the current 2N×2N block does not need to be split, and executing the block merging operation when the block merging operation is needed.

16. The non-transitory storage medium according to claim 15 , wherein determining whether the current 2N×2N block needs to be split is performed by:

determining that the current 2N×2N block needs to be split upon the condition that the pixel variance of the current 2N×2N block is greater than or equal to a threshold value; or

determining that the current 2N×2N block does not need to be split upon the condition that the pixel variance of the current 2N×2N block is less than the threshold value.

17. The non-transitory storage medium according to claim 15 , wherein the block merging operation comprising a first merging of 2N×2N block, the first merging of 2N×2N block is executed by:

determining whether the current 2N×2N block is the last block of a current 4N×4N block;

determining whether the current 4N×4N block comprises N×N block upon the condition that the current 2N×2N block is the last block of the current 4N×4N block;

determining whether the average values of pixels of four 2N×2N blocks in the current 4N×4N block are similar upon the condition that the current 4N×4N block does not comprise N×N block;

executing the first merging by merging the four 2N×2N blocks in the current 4N×4N block into one block upon the condition that the average values of pixels of the four 2N×2N blocks in the current 4N×4N block are similar.

18. The non-transitory storage medium according to claim 17 , wherein the average values of pixels of the four 2N×2N blocks in the current 4N×4N block are determined to be similar upon the condition that a deviation of the average values of pixels between every two 2N×2N blocks of the current 4N×4N block is less than a preset value.

19. The non-transitory storage medium according to claim 17 , wherein the first merging of 2N×2N block is executed by:

determining that the block merging operation is ended upon the condition that the current 4N×4N block comprises N×N block or that the average values of pixels of the four 2N×2N blocks in the current 4N×4N block are not similar.

20. The non-transitory storage medium according to claim 17 , wherein the first merging of 2N×2N block is executed by:

determining whether a second merging of 4N×4N block is needed upon the condition that the current 4N×4N block comprises N×N block, or that the average values of pixels of four 2N×2N blocks in the current 4N×4N block are similar, or that the first merging is executed.

21. The non-transitory storage medium according to claim 20 , wherein the second merging of 4N×4N block is executed by:

determining whether the current 2N×2N block is the last block of a current 8N×8N block;

determining whether the current 8N×8N block comprises blocks less than 4N×4N upon the condition that the current 2N×2N block is the last block of the current 8N×8N block;

determining whether the average values of pixels of four 4N×4N blocks in the current 8N×8N block are similar upon the condition that the current 8N×8N block does not comprise blocks less than 4N×4N block;

executing the second merging by merging the four 4N×4N blocks in the current 8N×8N block into one block upon the condition that the average values of pixels of the four 4N×4N blocks in the current 8N×8N block are similar.