MOVING IMAGE ENCODING APPARATUS AND CONTROL METHOD, AND COMPUTER PROGRAM

Abstract

A moving image encoding apparatus, comprising, a first image transformation unit adapted to transform image data into first image information, with reference to reference image data, a second image transformation unit adapted to inverse transform the first image information into reconstructed image data and a determination unit adapted to determine, based on the image data and the reconstructed image data, whether or not to use the reconstructed image data as the reference image data, wherein the determination unit calculates a peak signal-to-noise ratio (PSNR) from the reconstructed image data and the image data, and, if the PSNR is greater than or equal to a predetermined threshold, determines to use the reconstructed image data as the reference image data.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example of the configuration of a moving image encoding apparatus corresponding to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of the configuration of a moving image encoding apparatus corresponding to a second embodiment of the present invention.

FIG. 3 is a flowchart illustrating an example of a process pertaining to a moving image encoding apparatus corresponding to the first embodiment of the present invention.

FIG. 4 is a flowchart depicting an example of a process pertaining to a moving image encoding apparatus corresponding to the second embodiment of the present invention.

Claims

1. A moving image encoding apparatus which can select an arbitrary reference image, comprising: a first image transformation unit adapted to transform image data into first image information, with reference to reference image data;a second image transformation unit adapted to inverse transform the first image information into reconstructed image data; anda determination unit adapted to determine, based on the image data and the reconstructed image data, whether or not to use the reconstructed image data as the reference image data,wherein said determination unit calculates a peak signal-to-noise ratio (PSNR) from the reconstructed image data and the image data, and, if the PSNR is greater than or equal to a predetermined threshold, determines to use the reconstructed image data as the reference image data.

2. The moving image encoding apparatus according to claim 1, further comprising: a storage unit adapted to store the reconstructed image data, andwherein, if another image data is transformed by the first image transformation unit, said determination unit performs the determination further based on the frame distance between the other image data and the reconstructed image data stored in the storage unit.

3. The moving image encoding apparatus according to claim 1, wherein said first image transformation unit comprising, at least: an orthogonal transformation processing unit adapted to perform an orthogonal transformation on difference data between prediction image data based on the reference image data, and the image data; anda quantization unit adapted to quantize a result of the orthogonal transformation to generate the first image information, andsaid second image transformation unit comprising, at least:an inverse-quantization unit adapted to inverse-quantize the first image information;an inverse-orthogonal transformation unit adapted to inverse-orthogonal transform a result of the inverse-quantization; anda generation unit adapted to generate the reconstructed image data from a sum total of a result of the inverse-orthogonal transformation and the image data.

4. A moving image encoding apparatus which can select an arbitrary reference image, comprising: a first image transformation unit adapted to transform image data into a first image information based on an intra-frame prediction and an inter-frame prediction;a second image transformation unit adapted to inverse transform the first image information into reconstructed image data;a determination unit adapted to determine, based on a calculation concerning an image degradation of the reconstructed image data in relation to the image data, whether the reconstructed image data is suitable as the reference image data; anda motion detection unit adapted to generate a motion vector using the reconstructed image data determined to be suitable by said determination unit.

5. A control method of a moving image encoding apparatus which can select an arbitrary reference image, said method comprising: a first image transformation step of transforming image data into first image information, with reference to reference image data;a second image transformation step of inverse transforming the first image information into reconstructed image data; anda determination step of determining, based on the image data and the reconstructed image data, whether or not to use the reconstructed image data as the reference image data,wherein in said determination step, a peak signal-to-noise ratio (PSNR) is calculated from the reconstructed image data and the image data, and, if the PSNR is greater than or equal to a predetermined threshold, it is determined to use the reconstructed image data as the reference image data.

6. The control method of the moving image encoding apparatus according to claim 5, wherein said moving image encoding apparatus comprising a storage unit adapted to store the reconstructed image data, andin said method, if another image data is transformed in the first image transformation step, the determination in said determination step further based on the frame distance between the other image data and the reconstructed image data stored in the storage unit.

7. The control method of the moving image encoding apparatus according to claim 1, wherein said first image transformation step comprising, at least:an orthogonal transformation step of performing an orthogonal transformation on difference data between prediction image data based on the reference image data, and the image data; anda quantization step of quantizing a result of the orthogonal transformation to generate the first image information, andsaid second image transformation step comprising, at least:an inverse-quantization step of inverse-quantizing the first image information;an inverse-orthogonal transformation step of inverse-orthogonal transforming a result of the inverse-quantization; anda generation step of generating the reconstructed image data from a sum total of a result of the inverse-orthogonal transformation and the image data.

8. A control method of a moving image encoding apparatus which can select an arbitrary reference image, comprising: a first image transformation step of transforming image data into first image information based on an intra-frame prediction and an inter-frame prediction;a second image transformation step of inverse transforming the first image information into reconstructed image data;a determination step of determining, based on a calculation concerning an image degradation of the reconstructed image data in relation to the image data, whether the reconstructed image data is suitable as the reference image data; anda motion detection step of generating a motion vector using the reconstructed image data determined to be suitable in said determination step.

9. A computer program stored in a computer-readable storage medium wherein the computer program causes a computer to function as a moving image encoding apparatus which can select an arbitrary reference image, said apparatus comprising: a first image transformation unit adapted to transform image data into first image information, with reference to reference image data;a second image transformation unit adapted to inverse transform the first image information into reconstructed image data; anda determination unit adapted to determine, based on the image data and the reconstructed image data, whether or not to use the reconstructed image data as the reference image data,wherein said determination unit calculates a peak signal-to-noise ratio (PSNR), from the reconstructed image data and the image data, and, if the PSNR is greater than or equal to a predetermined threshold, determines to use the reconstructed image data as the reference image data.

10. A computer program stored in a computer-readable storage medium wherein the computer program causes a computer to function as a moving image encoding apparatus which can select an arbitrary reference image, comprising: a first image transformation unit adapted to transform image data into first image information based on an intra-frame prediction and an inter-frame prediction;a second image transformation unit adapted to inverse transform the first image information into reconstructed image data;a determination unit adapted to determine, based on a calculation concerning an image degradation of the reconstructed image data in relation to the image data, whether the reconstructed image data is suitable as the reference image data; anda motion detection unit adapted to generate a motion vector using the reconstructed image data determined to be suitable by said determination unit.