Motion image coding apparatus, and control method and program of the apparatus
A motion detector detects the motion of an imaging device. On the basis of the detected motion information, a selector selects, from a plurality of frame memories for storing a plurality of frame data, a frame memory for storing reference frame data to be referred to when frame data to be coded is coded. A motion estimator estimates a motion vector on the basis of the reference frame data stored in the selected frame memory and the frame data to be coded. The frame data to be coded is coded by using the estimated motion vector, and the coded data is output.
1. A motion image coding apparatus which codes a motion image by executing motion compensation for frame data to be coded by referring to a plurality of frame data in the motion image, comprising:
a detecting unit that detects a motion of an imaging device;
a plurality of storage units that stores the plurality of frame data;
a determination unit that determines a number of reference frames to be referred when frame data to be coded is coded, wherein, in a case that motion information detected by said detecting unit is larger than a predetermined value, the number of reference frames is less than the number of reference frames in a case that motion information is equal or to smaller than the predetermined value;
a selecting unit that selects, from said plurality of storage units, storage units where frame data is stored, according to the number of reference frames determined by said determination unit;
an estimating unit that estimates a motion vector on the basis of frame data stored in the storage units selected by said selecting units and frame data to be coded;
a coding unit that codes frame data to be coded by using the motion vector estimated by said estimating unit; and
an output unit that outputs the coded data which is coded by said coding unit.
2. The motion image coding apparatus according to claim 1 , wherein said detecting unit detects the motion of said imaging device on the basis of a motion image sensed by said imaging device.
3. The motion image coding apparatus according to claim 1 , wherein said selecting unit comprises a control unit that controls write/read and power supply to said plurality of storage units, motion according to the number of reference frames determined by said determination unit.
4. The motion image coding apparatus according to claim 1 , further comprising a setting unit that sets an image sensing mode of said imaging device,
wherein said selecting unit comprises a control unit that controls write/read and power supply to said plurality of storage units on the basis of the image sensing mode set by said setting unit.
5. The motion image coding apparatus according to claim 3 or 4 , wherein said control unit stops power supply to storage units not selected by said selecting unit.
6. The motion image coding apparatus according to claim 1 , further comprising a search range control unit that controls a motion vector search range of said estimating unit on the basis of the motion image detected by said detecting unit.
7. A control method of a motion image coding apparatus which comprises a plurality of storage units for storing a plurality of frame data in a motion image, and codes the motion image by executing motion compensation for frame data to be coded by referring to frame data stored in the plurality of storage units, comprising:
a detection step of detecting a motion of an imaging device;
a determination step of determining a number of reference frames to be referred when frame data to be coded is coded, wherein, in a case that motion information detected by said detection step is larger than a predetermined value, the number of reference frames is less than the number of reference frames in a case that motion information is equal or to smaller than the predetermined value;
a selection step of selecting, from the plurality of storage units, storage units where frame data is stored, according to the number of reference frames determined by said determination step;
an estimation step of estimating a motion vector on the basis of frame data stored in the storage units selected in said selection step and frame data to be coded;
a coding step of coding the frame data to be coded by using the motion vector estimated in said estimation step; and
an output step of outputting the coded data which is coded in said coding step.
8. A program, stored on a non-transitory computer-readable storage medium, for implementing control of a motion image coding apparatus which comprises a plurality of storage units for storing a plurality of frame data in a motion image, and codes the motion image by executing motion compensation for frame data to be coded by referring to frame data stored in the plurality of storage units, comprising program codes of:
a detection step of detecting a motion of an imaging device;
a determination step of determining a number of reference frames to be referred when frame data to be coded is coded, wherein, in a case that motion information detected by said detection step is larger than a predetermined value, the number of reference frames is less than the number of reference frames in a case that motion information is equal or to smaller than the predetermined value;
a selection step of selecting, from the plurality of storage units, storage units where frame data is stored, according to the number of reference frames determined by said determination step;
an estimation step of estimating a motion vector on the basis of frame data stored in the storage units selected in said selection step and frame data to be coded;
a coding step of coding the frame data to be coded by using the motion vector estimated in said estimation step; and
an output step of outputting the coded data which is coded in said coding step.