Apparatus and method for encoding and decoding moving picture using wavelet transformation and motion estimation

• US 20030118108A1
• Filed: 12/20/2002
• Published: 06/26/2003
• Est. Priority Date: 12/20/2001
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Ho Keun, Ha, Yeong Ho, Shin, Jong Keun
• Granted Patent: US 6,985,528 B2
• Time in Patent Office: Days
• US Class Current: 375/240.19
• CPC Class Codes: H04N 19/43 Hardware specially adapted for motion estimation or compensation
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets

Abstract

An encoding and decoding apparatus using a wavelet transformation and motion estimation is disclosed. The apparatus includes an input module for receiving an image data, a wavelet module for wavelet-transforming the image data received through the input module, an estimation/compensation module, a storage module for storing the image data being transmitted from the input module and transmitting the stored data in a request from the respective modules, an output module for outputting one bit stream by coupling the data being inputted from the wavelet module and a data corresponding to the motion vector being inputted from the storage module, and a control module for controlling operations of the respective modules. According to the present invention, though memories of small amount are used, whole image can be wavelet-transformed and a motion of a block can be estimated in real time when the encoding and decoding a moving picture at real time.

Claims

1. An apparatus for encoding a moving picture by using wavelet transformation based on a frame and motion estimation based on a block comprising:

an input module for receiving original image data;

a wavelet module for wavelet-processing the data received through the input module;

a motion estimation module for obtaining a motion vector;

a motion compensation module for motion compensation by using the motion vector;

a storage module for storing the original image data being transmitted from the input module, the motion vector being transmitted from the motion estimation module, and difference signal data being transmitted from the motion compensation module, and for transmitting the stored data to a corresponding module according to request of the corresponding module;

an output module for outputting one bit stream by coupling the data being inputted from the wavelet module with the motion vector being inputted from the storage module; and

a control module for controlling operations of the respective modules.

2. The apparatus of claim 1, wherein the input module comprises an input buffer and output buffer,

wherein the input buffer transmits the original image data being inputted into the input module to the storage module,

wherein the output buffer reads data corresponding to the difference between a current frame and a previous frame being transmitted from the storage module and transmits the read data to the wavelet module.

3. The apparatus of claim 2, wherein the input buffer of the input module comprises:

a demultiplexer for separating a brightness data and chrominance data from the original image data being inputted into the input module respectively;

a brightness FIFO and a chrominance first-in first-out (FIFO) for storing the separated brightness data and the separated chrominance data outputting from the demultiplexer respectively;

a recording controller for controlling the brightness FIFO and the chrominance FIFO, and an operation of the demultiplexer; and

a reading controller for controlling whether data is outputted from the brightness FIFO and the chrominance FIFO.

4. The apparatus of claim 2, wherein the output buffer of the input module comprises:

a brightness FIFO and a chrominance FIFO for respectively separating and storing the brightness data and the separated chrominance data received from the storage module;

a splitter controller for controlling data input from the brightness FIFO and the chrominance FIFO;

a multiplexer for selecting a brightness data and chrominance data to be inputted into the wavelet module; and

a FIFO reading controller for controlling outputs of the brightness FIFO and the chrominance FIFO and an operation of the multiplexer.

5. The apparatus of claim 4, where the brightness FIFO of the output buffer comprises:

an odd brightness FIFO for storing an odd line brightness data; and

an even brightness FIFO for storing an even line brightness data;

wherein the chrominance FIFO of the output buffer comprises;

an odd chrominance FIFO for storing an odd line chrominance data; and

an even chrominance FIFO for storing an even line chrominance data.

6. The apparatus of claim 4, wherein the brightness FIFO and the chrominance FIFO respectively comprises:

a dual port RAM capable of performing reading and writing operations simultaneously;

a recording controller for generating an address for recording data on the dual port RAM;

a reading controller for generating an address for reading data from the dual port RAM; and

a flag controller for indicating whether a state of the dual port RAM is full or empty.

7. The apparatus of claim 1, wherein the motion estimation module comprises:

at least one input buffer for storing data being transmitted from the storing module;

an input buffer controller for controlling an output sequence of the data stored in the input buffer;

a delay for delaying an output data from the input buffer according to the input buffer controller;

a multiplexer for transmitting data outputted from the delay; and

a motion estimator for obtaining the motion vector by processing data outputted from the multiplexer.

8. The apparatus of claim 7, wherein the data being inputted into the input buffer of the motion estimation module comprises data corresponding to a reference block of a present frame and data corresponding to blocks within a corresponding searching region of a previous frame.

9. The apparatus of claim 7, wherein the motion estimator of the motion estimation module comprises:

a processing element (PE) for calculating and accumulating an absolute error value between the data of the reference block and the data of the searching region; and

a shift register array having a two dimensional systolic structure,

wherein a pixel value is inputted into the shift register array, and the inputted pixel value of the reference block is inputted again into the PE.

10. The apparatus of claim 9, wherein a width of the register shift array of the motion estimator is identical with a width of the searching region.

11. The apparatus of claim 9, wherein the PE of the motion estimator has a size identical with a length of a row of the reference block.

12. The apparatus of claim 9, wherein the PE of the motion estimator comprises:

a reference input shift register (RSR) for transferring the reference block being inputted during a first early time to a next PE;

an absolute difference computer (ADC) for calculating an absolute difference between data regarding the reference block inputted from the reference input shift register and data of the searching region;

a first and second delays for transferring data being transferred from a previous PE after holding the transferred data for one clock; and

an adder for accumulating data regarding the reference block and data regarding a block of the searching region.

13. The apparatus of claim 12, wherein the processing element further comprises a third delay for tuning a synchronizing between the absolute difference computer and the adder.

14. The apparatus of claim 7, wherein the input buffer of the motion estimation module has a capacity as much as capable of accommodating data necessary for estimating motion of one macro block.

15. The apparatus of claim 1, wherein the motion compensation module comprises:

an input buffer for receiving data of a macro block which is stored in an address of the storage module being made by the motion vector;

a processing element for alternately receiving data regarding a previous frame and data regarding of a present frame and obtaining a difference value between the inputted data; and

an output buffer for outputting a result of the processing element in order for storing the result to the storage module.

16. The apparatus of claim 15, wherein the input buffer of the motion compensation module uses four 512 byte Static Random Access Memories (SRAM).

17. The apparatus of claim 15, wherein the output buffer of the motion compensation module changes order of an 8-bit result data simultaneously outputted from four processing elements and stores the change data in 32-bit format.

18. The apparatus of claim 1, wherein the storage module comprises a synchronous graphic RAM having two banks.

19. The apparatus of claim 1, wherein the storage module comprises a memory capable of storing an image data with respect to one frame transmitted from the input module, an image data with respect to two previous frames to be transmitted to motion estimation module and the compensation module, data corresponding to a motion vector generated as a result of the motion estimation in the motion estimation module, and data corresponding to a difference signal generated as a result of the motion compensation in the motion compensation module.

20. The apparatus of claim 1, wherein the storage module comprises a memory comprised of a first and second banks, and stores an image data in the respective banks transmitted from the input module by a field unit by storing data of a first odd line and a first even line of the image data in the first bank and data of a second odd line and a second even line of the image data in the second bank.

21. The apparatus of claim 1, wherein the storage module comprises a memory comprised of a first and second banks, and stores the difference signal data being transmitted from the motion compensation module in the respective banks by storing the difference signal data of a first block and second block in the first bank and the difference signal data of a third block and a fourth block in the second bank.

22. The apparatus of claim. 1., wherein the output module comprises:

a FIFO recording controller for gating an input of a stream FIFO and monitoring whether the stream FIFO is full or not;

a FIFO read controller for gating an output of the stream FIFO and monitoring whether the stream FIFO is empty or not;

a coupler for coupling the input data inputted from the wavelet module and the motion vector data inputted from the storage module; and

the stream FIFO for storing the data inputted from the coupler.

23. The apparatus of claim 22, wherein the stream FIFO of the output module has a size capable of storing data corresponding to one frame.

24. The apparatus of claim 1, wherein the control module controls on an I mode and P mode, and generates control an address of the storage module and signals with respect to the respective modules.

25. The apparatus of claim 1, wherein the storage module receives and transmits data in 32-bit, an input buffer of the input module includes an 8-to-32 converter, and an output buffer of the input module includes a 32-to-8 converter.

26. The apparatus of claim 1, wherein the wavelet module comprises a first and second wavelet modules, the first and second wavelet modules process an odd data and even data separately.

27. A moving picture decoding apparatus, using motion estimation based on a block and a wavelet transformation based on a frame, for decoding an image signal inputted by being encoded in one bit-stream type, the moving picture decoding apparatus comprising:

an input module for receiving the encoded image signal of the one bit-stream type;

a wavelet module for receiving a difference signal among the image signal from the input module and reversely wavelet-transforming the difference signal;

a FIFO for storing a signal outputted from the wavelet module;

a storage module to which a motion vector among the image signal is transmitted from the input module and the reverse-wavelet-transformed difference signal is transmitted from the FIFO;

a motion compensation module for compensating a motion by using the motion vector and the difference signal transmitted from the storage module; and

an output buffer for finally outputting an image signal encoded by the motion compensation module received from the storage module.