Abstract: A video encoding method, a video encoding apparatus, a video decoding method, and a video decoding apparatus are provided. The video encoding method includes producing a fast transform matrix based on a transform matrix which is used for frequency transformation on a block which has a predetermined size; producing a transformed block by transforming the block having the predetermined size by using the fast transform matrix; and performing scaling with respect to the transformed block in order to correct a difference between the transform matrix used for the frequency transformation and the fast transform matrix.

Abstract: A video encoding method, a video encoding apparatus, a video decoding method, and a video decoding apparatus are provided. The video encoding method includes producing a fast transform matrix based on a transform matrix which is used for frequency transformation on a block which has a predetermined size; producing a transformed block by transforming the block having the predetermined size by using the fast transform matrix; and performing scaling with respect to the transformed block in order to correct a difference between the transform matrix used for the frequency transformation and the fast transform matrix.

Abstract: A video encoding method, a video encoding apparatus, a video decoding method, and a video decoding apparatus are provided. The video encoding method includes producing a fast transform matrix based on a transform matrix which is used for frequency transformation on a block which has a predetermined size; producing a transformed block by transforming the block having the predetermined size by using the fast transform matrix; and performing scaling with respect to the transformed block in order to correct a difference between the transform matrix used for the frequency transformation and the fast transform matrix.

Abstract: A method of encoding a video is provided, the method includes: determining a filtering boundary on which deblocking filtering is to be performed based on at least one data unit from among a plurality of coding units that are hierarchically configured according to depths indicating a number of times at least one maximum coding unit is spatially spilt, and a plurality of prediction units and a plurality of transformation units respectively for prediction and transformation of the plurality of coding units, determining filtering strength at the filtering boundary based on a prediction mode of a coding unit to which pixels adjacent to the filtering belong from among the plurality of coding units, and transformation coefficient values of the pixels adjacent to the filtering boundary, and performing deblocking filtering on the filtering boundary based on the determined filtering strength.

Abstract: A computed tomography (CT) apparatus includes a reconstruction unit which reconstructs a first CT image corresponding to a field of view (FOV) by using a first sinogram acquired by a CT scan of an object; and a correction unit which acquires a second sinogram by performing forward projection on the first CT image and acquires a second CT image by using the second sinogram and a third sinogram representing a portion of the object that is not included in the FOV. Thus, the CT apparatus reduces generation of image errors to thereby provide a high-quality reconstructed CT image.

Abstract: Provided are a method and apparatus for encoding a video signal and a method and apparatus for decoding a video signal. The method of encoding the video signal includes: determining an optimum scaling bit depth of the video signal in consideration of a maximum bit number of an intermediate value obtained during transformation of the video signal and a maximum bit precision of the video signal; scaling the video signal according to a local shift value corresponding to a difference between the determined optimum scaling bit depth and an original bit depth of the video signal; and transforming the scaled video signal.

Abstract: A video encoding method, a video encoding apparatus, a video decoding method, and a video decoding apparatus are provided. The video encoding method includes producing a fast transform matrix based on a transform matrix which is used for frequency transformation on a block which has a predetermined size; producing a transformed block by transforming the block having the predetermined size by using the fast transform matrix; and performing scaling with respect to the transformed block in order to correct a difference between the transform matrix used for the frequency transformation and the fast transform matrix.

Abstract: A method of encoding a video is provided, the method includes: determining a filtering boundary on which deblocking filtering is to be performed based on at least one data unit from among a plurality of coding units that are hierarchically configured according to depths indicating a number of times at least one maximum coding unit is spatially spilt, and a plurality of prediction units and a plurality of transformation units respectively for prediction and transformation of the plurality of coding units, determining filtering strength at the filtering boundary based on a prediction mode of a coding unit to which pixels adjacent to the filtering belong from among the plurality of coding units, and transformation coefficient values of the pixels adjacent to the filtering boundary, and performing deblocking filtering on the filtering boundary based on the determined filtering strength.

Abstract: Provided are a method and apparatus for encoding a video signal and a method and apparatus for decoding a video signal. The method of encoding the video signal includes: determining an optimum scaling bit depth of the video signal in consideration of a maximum bit number of an intermediate value obtained during transformation of the video signal and a maximum bit precision of the video signal; scaling the video signal according to a local shift value corresponding to a difference between the determined optimum scaling bit depth and an original bit depth of the video signal; and transforming the scaled video signal.

Abstract: Provided are a method and apparatus for encoding a video signal and a method and apparatus for decoding a video signal. The method of encoding the video signal includes: determining an optimum scaling bit depth of the video signal in consideration of a maximum bit number of an intermediate value obtained during transformation of the video signal and a maximum bit precision of the video signal; scaling the video signal according to a local shift value corresponding to a difference between the determined optimum scaling bit depth and an original bit depth of the video signal; and transforming the scaled video signal.

Abstract: A video encoding method, a video encoding apparatus, a video decoding method, and a video decoding apparatus are provided. The video encoding method includes producing a fast transform matrix based on a transform matrix which is used for frequency transformation on a block which has a predetermined size; producing a transformed block by transforming the block having the predetermined size by using the fast transform matrix; and performing scaling with respect to the transformed block in order to correct a difference between the transform matrix used for the frequency transformation and the fast transform matrix.

Abstract: A method of encoding a video is provided, the method includes: determining a filtering boundary on which deblocking filtering is to be performed based on at least one data unit from among a plurality of coding units that are hierarchically configured according to depths indicating a number of times at least one maximum coding unit is spatially spilt, and a plurality of prediction units and a plurality of transformation units respectively for prediction and transformation of the plurality of coding units, determining filtering strength at the filtering boundary based on a prediction mode of a coding unit to which pixels adjacent to the filtering belong from among the plurality of coding units, and transformation coefficient values of the pixels adjacent to the filtering boundary, and performing deblocking filtering on the filtering boundary based on the determined filtering strength.

Abstract: Provided are a method and apparatus for encoding a video signal and a method and apparatus for decoding a video signal. The method of encoding the video signal includes: determining an optimum scaling bit depth of the video signal in consideration of a maximum bit number of an intermediate value obtained during transformation of the video signal and a maximum bit precision of the video signal; scaling the video signal according to a local shift value corresponding to a difference between the determined optimum scaling bit depth and an original bit depth of the video signal; and transforming the scaled video signal.

Abstract: An image processing method of an image processing apparatus includes projecting centers of pixels of a pixel grid onto a preset common axis, mapping a boundary of a detector cell comprised in the detection unit on the preset common axis, and determining a detector value based on the projecting the centers of the pixels onto the preset common axis and the mapping the boundary of the detector cell on the preset common axis.

Abstract: A video encoding method, a video encoding apparatus, a video decoding method, and a video decoding apparatus are provided. The video encoding method includes producing a fast transform matrix based on a transform matrix which is used for frequency transformation on a block which has a predetermined size; producing a transformed block by transforming the block having the predetermined size by using the fast transform matrix; and performing scaling with respect to the transformed block in order to correct a difference between the transform matrix used for the frequency transformation and the fast transform matrix.

Abstract: A medical imaging apparatus includes a data acquirer configured to acquire measured data acquired by detecting an X-ray transmitted by an X-ray source to an object, and an image processor configured to acquire an initial image based on the measured data, alternately estimate region of interest (ROI)-outside measured data and ROI-inside measured data based on the measured data and the initial image, and acquire a reconstructed image based on the ROI-inside measured data.

Abstract: A method of encoding a video is provided, the method includes: determining a filtering boundary on which deblocking filtering is to be performed based on at least one data unit from among a plurality of coding units that are hierarchically configured according to depths indicating a number of times at least one maximum coding unit is spatially spilt, and a plurality of prediction units and a plurality of transformation units respectively for prediction and transformation of the plurality of coding units, determining filtering strength at the filtering boundary based on a prediction mode of a coding unit to which pixels adjacent to the filtering belong from among the plurality of coding units, and transformation coefficient values of the pixels adjacent to the filtering boundary, and performing deblocking filtering on the filtering boundary based on the determined filtering strength.

Abstract: A video encoding method, a video encoding apparatus, a video decoding method, and a video decoding apparatus are provided. The video encoding method includes producing a fast transform matrix based on a transform matrix which is used for frequency transformation on a block which has a predetermined size; producing a transformed block by transforming the block having the predetermined size by using the fast transform matrix; and performing scaling with respect to the transformed block in order to correct a difference between the transform matrix used for the frequency transformation and the fast transform matrix.

Abstract: A method of encoding a video is provided, the method includes: determining a filtering boundary on which deblocking filtering is to be performed based on at least one data unit from among a plurality of coding units that are hierarchically configured according to depths indicating a number of times at least one maximum coding unit is spatially spilt, and a plurality of prediction units and a plurality of transformation units respectively for prediction and transformation of the plurality of coding units, determining filtering strength at the filtering boundary based on a prediction mode of a coding unit to which pixels adjacent to the filtering belong from among the plurality of coding units, and transformation coefficient values of the pixels adjacent to the filtering boundary, and performing deblocking filtering on the filtering boundary based on the determined filtering strength.

Abstract: Provided are a method and apparatus for encoding a video signal and a method and apparatus for decoding a video signal. The method of encoding the video signal includes: determining an optimum scaling bit depth of the video signal in consideration of a maximum bit number of an intermediate value obtained during transformation of the video signal and a maximum bit precision of the video signal; scaling the video signal according to a local shift value corresponding to a difference between the determined optimum scaling bit depth and an original bit depth of the video signal; and transforming the scaled video signal.