Image processing apparatus and method

1. An image processing apparatus comprising:

circuitry configured to

decode an encoded image;

add together an image that has been decoded and a prediction image, and generate a decoded image;

perform motion compensation using, as a reference frame, a frame formed of the decoded image and using a motion vector in the encoded image, and extract a motion compensation image corresponding to the prediction image from the reference frame;

perform intra-frame prediction for a present frame for which the prediction image is to be generated, and generate an intra-prediction image corresponding to the prediction image from a portion of the decoded image; and

generate the prediction image by performing a filtering process to compensate the extracted motion compensation image and the generated intra-prediction image for high-frequency components by utilizing correlation in a time direction that is included in the extracted motion compensation image and the generated intra-prediction image, generation of the prediction image including:

applying a low-pass filter to a difference image between the extracted motion compensation image and the generated intra-prediction image,

applying a high-pass filter to an image obtained by applying the low-pass filter, and

adding the image obtained by applying the low-pass filter and an image obtained by applying the high-pass filter to the generated intra-prediction image.

2. The image processing apparatus according to claim 1 , wherein the circuitry is configured to add the image obtained by applying the low-pass filter and the image obtained by applying the high-pass filter to a motion compensation image extracted from a preceding frame with respect to a time of the prediction image.

3. The image processing apparatus according to claim 1 , wherein the circuitry is configured to:

perform unidirectional prediction using a plurality of motion compensation images, and generate the prediction image;

perform bidirectional prediction using a plurality of motion compensation images, and generate the prediction image; and

judge whether the prediction image is to be generated through unidirectional prediction, generated through bidirectional prediction, or generated through the filtering process using an identification flag included in a header of the encoded image.

4. An image processing method comprising:

decoding, using a processor, an encoded image;

adding, using the processor, together an image that has been decoded and a prediction image, and generating a decoded image;

performing, using the processor, motion compensation using, as a reference frame, a frame formed of the generated decoded image and using a motion vector in the encoded image, and extracting a motion compensation image corresponding to the prediction image from the reference frame;

performing, using the processor, intra-frame prediction for a present frame for which the prediction image is to be generated, and generating an intra-prediction image corresponding to the prediction image from a portion of the decoded image; and

generating, using the processor, the prediction image by performing a filtering process for compensating the motion compensation image and the intra-prediction image for high-frequency components by utilizing correlation in a time direction that is included in the motion compensation image and the intra-prediction image,

wherein said generating the prediction image includes:

performing low-pass filtering of a difference image between the extracted motion compensation image and the generated intra-prediction image,

performing high-pass filtering to an image obtained by performing the low-pass filtering, and

adding the image obtained by performing the low-pass filtering and the image obtained by performing the high-pass filtering to the generated intra-prediction image to obtain the prediction image.

5. An image processing apparatus comprising:

circuitry including:

an encoding circuitry portion that encodes an original image that is an encoding target image, and that generates an encoded image;

a detecting circuitry portion that detects a motion vector based on an image and the original image, the image being obtained by performing local decoding based on a residual signal indicating a difference between the original image and a prediction image;

an extracting circuitry portion that performs motion compensation using, as a reference frame, a frame formed of the image obtained by performing local decoding and using the motion vector detected by the detecting circuitry portion, and that extracts a motion compensation image corresponding to the prediction image from the reference frame;

an intra-prediction image generating circuitry portion that performs intra-frame prediction for a present frame for which the prediction image is to be generated, and that generates an intra-prediction image corresponding to the prediction image from a portion of an image of the frame; and

a generating circuitry portion that generates the prediction image by performing a filtering process for compensating the motion compensation image extracted by the extracting circuitry portion and the intra-prediction image generated by the intra-prediction image generating circuitry portion for high-frequency components by utilizing correlation in a time direction that is included in the motion compensation image,

wherein the generating circuitry portion includes:

a first filter that applies a low-pass filter to a difference image between the motion compensation image extracted by the first extracting circuitry portion and the intra-prediction image generated by the intra-prediction image generating circuitry portion,

a second filter that applies a high-pass filter to an image obtained by applying the low-pass filter using the first filter, and

an adder that adds the image obtained by applying the low-pass filter using the first filter and an image obtained by applying the high-pass filter using the second filter to the intra-prediction image generated by the intra-prediction image generating circuitry portion.

6. The image processing apparatus according to claim 5 , wherein the adder adds the image obtained by applying the low-pass filter using the first filter and the image obtained by applying the high-pass filter using the second filter to a motion compensation image extracted from a preceding frame with respect to a time of the prediction image.

7. The image processing apparatus according to claim 5 , wherein the encoding circuitry portion incorporates an identification flag into a header of the encoded image, the identification flag identifying whether a prediction image to be added to an image decoded by a decoding apparatus is to be generated through unidirectional prediction, generated through bidirectional prediction, or generated through the filtering process.

8. An image processing method comprising:

encoding, using processing circuitry, an original image that is an encoding target image, and generating an encoded image;

detecting, using the processing circuitry, a motion vector on the basis of an image and the original image, the image being obtained by performing local decoding on the basis of a residual signal indicating a difference between the original image and a prediction image;

performing, using the processing circuitry, motion compensation using, as a reference frame, a frame formed of the image obtained by performing local decoding and using the detected motion vector, and extracting a motion compensation image corresponding to the prediction image from the reference frame;

performing, using the processing circuitry, intra-frame prediction for a present frame for which the prediction image is to be generated, and generating an intra-prediction image corresponding to the prediction image from a portion of an image of the frame; and

generating, using the processing circuitry, the prediction image by performing a filtering process for compensating the extracted motion compensation image and the generated intra-prediction image for high-frequency components by utilizing correlation in a time direction that is included in the motion compensation image,

wherein said generating the prediction image includes:

performing low-pass filtering to a difference image between the extracted motion compensation image and the generated intra-prediction image,

performing high-pass filtering to an image obtained by performing the low-pass filtering, and

adding the image obtained by performing the low-pass filtering and the image obtained by performing the high-pass filtering to the generated intra-prediction image to obtain the prediction image.