Display driver and method of operating image data processing device

1. A display driving device comprising:

an encoding unit configured to,

generate mode information based on a macro block and at least one reference pixel, the mode information indicating a selected mode from a plurality of modes, each of the plurality of modes indicating a way to divide pixels in the macro block into selection pixels and non-selection pixels, and the selected mode represented by information indicating selected locations of the selection pixels,

generate a compressed bit stream of the selection pixels in the macro block based on the mode information by compressing a size of the selection pixels,

generate a reconstruction reference value for each of the non-selection pixels, and

generate a final bit stream including the mode information, the reconstruction reference value, and the compressed bit stream; and

a frame memory configured to store the final bit stream and provide the final bit stream to a decoding unit,

wherein the selection pixels are pixels in the macro block selected for undergoing a compression operation,

the non-selection pixels are pixels not selected for undergoing the compression operation, and

the reconstruction reference value indicates encoding information for the non-selection pixels.

2. The display driving device of claim 1 , wherein

the at least one reference pixel includes a first reference pixel and a second reference pixel; and

the encoding unit is further configured to,

generate the fit t-mode information based on the macro block, the first reference pixel, and the second reference pixel,

generate the compressed bit stream based on the final-mode information, and

generate the final bit stream using the mode information, the reconstruction reference value, and the compressed bit stream.

3. The display driving device of claim 2 , wherein the encoding unit is further configured to reconstruct a pixel from a previous final bit stream as the first reference pixel, and reconstruct a compressed selection pixel as the second reference pixel.

4. The display driving device of claim 3 , wherein the encoding unit is configured to calculate, for each of the plurality of modes, a plurality of difference values including a first difference value and a second difference value, the first difference value being a difference between one of the non-selection pixels and the first reference pixel, and the second difference value being a difference between the non-selection pixel and an average value of the first reference pixel and the second reference pixel.

5. The display driving device of claim 4 , wherein the encoding unit is further configured to,

determine, for each of the plurality of modes, a minimum one of the plurality of difference values associated with each of the non-selection pixels, and determine, for each of the plurality of modes, a sum of the minimum difference values as a mode error, and

generate the mode information based on mode errors for the plurality of modes.

6. The display driving device of claim 5 , wherein the sum is one of SAD (sum of absolute differences), SSD (sum of squared differences), MAD (mean absolute difference), or NCC (normalized cross-correlation).

7. The display driving device of claim 2 , wherein the encoding unit is configured to generate the compressed bit stream by compressing the selection pixels based on the mode information.

8. The display driving device of claim 1 , wherein the decoding unit is configured to,

generate the compressed bit stream and decoded mode information by parsing the final bit stream,

generate selection pixel information using the compressed bit stream, and

generate a decoded macro block based on the selection pixel information and the decoded mode information.

9. The display driving device of claim 8 , wherein the decoding unit is configured to,

parse the final bit stream into the compressed bit stream, a header, and the reconstruction reference value, and

generate the decoded mode information based on the header and the reconstruction reference value.

10. The display driving device of claim 9 , wherein the decoding unit is further configured to reconstruct the selection pixels from the selection pixel information, and reconstruct the non-selection pixels from the mode information.

11. A host providing image compressed data to a display driving chip including a frame memory, the host comprising:

a host controller configured to transmit a control signal and un-compressed image data; and

an encoding unit configured to receive the control signal and the un-compressed image data with the host controller, the encoding unit configured to,

generate mode information based on a macro block and at least one reference pixel, the mode information indicating a selected mode from a plurality of modes, each of the plurality of modes indicating a way to divide pixels in the macro block into selection pixels and non-selection pixels, and the selected mode represented by information indicating selected locations of the selection pixels,

generate a compressed bit stream of the selection pixels in the macro block based on the mode information by compressing a size of the selection pixels,

generate a reconstruction reference value for each of the non-selection pixels, and

generate a final bit stream including the mode information, the reconstruction reference value, and the compressed bit stream,

wherein the selection pixels are pixels in the macro block selected for undergoing a compression operation,

the non-selection pixels are pixels not selected for undergoing the compression operation, and

the reconstruction reference value indicates encoding information for the non-selection pixels.

12. The host of claim 11 , wherein:

the at least one reference pixel includes a first reference pixel and a second reference pixel; and

the encoding unit is further configured to,

generate the mode information based on the macro block, the first reference pixel, and the second reference pixel, and

generate the compressed bit stream based on the mode information.

13. The host of claim 12 , wherein the encoding unit is further configured to reconstruct a pixel from a previous final bit stream as the first reference pixel, and reconstruct a compressed selection pixel as the second reference pixel.

14. The host of claim 13 , wherein the encoding unit is configured to calculate, for each of the plurality of modes, a plurality of difference values including a first difference value and a second difference value, the first difference value being a difference between one of the non-selection pixels and the first reference pixel, and the second difference value being a difference between the non-selection pixel and an average value of the first reference pixel and the second reference pixel.

15. The host of claim 14 , wherein the encoding unit is further configured to,

determine, for each of the plurality of modes, a minimum one of the plurality of difference values associated with each of the non-selection pixels, and determine, for each of the plurality of modes, a sum of the minimum difference values as a mode error, and

generate the mode information based on mode errors for the plurality of modes.

16. The host of claim 15 , wherein the sum is one of SAD (sum of absolute differences), SSD (sum of squared differences), MAD (mean absolute difference), or NCC (normalized cross-correlation).

17. The host of claim 11 , wherein the encoding unit is configured to generate the compressed bit stream by compressing the selection pixels based on the mode information.