Image coding device, image coding method, image coding integrated circuit and image coding program

Abstract

An image coding device ( 100 ) which codes input image data includes a coding flag generation unit ( 101 ) which determines whether or not the input image data is image data included in data of a moving picture which shows a motion of a predetermined motion amount or greater, and generate coding flag information which indicates a result of the determination, a coding method determination unit ( 102 ) which determines such a coding method in which the input image data references coded image data that the coded image data in the case where the coding flag information generated by the coding flag generation unit indicates that the input image data is included in the data of the moving picture is closer to the input image data than otherwise, and an mage coding unit ( 103 ) which compression-codes the input image data using the coding method determined by the coding method determination unit.

1 - 10 . (canceled) 
     
     
         11 . An image coding device, comprising:
 an input unit configured to receive input image data having an interlace structure; and   a coding unit configured to code a first picture using a coding method compliant with a predetermined moving-picture compression standard, the first picture being a current picture to be coded among pictures included in the input image data;   wherein said coding unit is configured to   select, depending on a motion amount for the first picture, a first number or fewer of reference pictures from (i) a picture included in a same frame as the first picture and being of parity different from parity of the first picture and (ii) pictures included in a frame preceding or following the first picture, the first number being an integer equal to or greater than one, and   code the first picture using the selected reference pictures.   
     
     
         12 . The image coding device according to  claim 11 ,
 wherein said coding unit is configured to set, in one or more reference pictures of the selected reference pictures, ranges to be searched for motion vectors to be used in the coding of the first picture, when the number of the selected pictures is a second number which is smaller than the first number.   
     
     
         13 . The image coding device according to  claim 12 ,
 wherein the ranges to be searched set by said coding unit are different from each other.   
     
     
         14 . The image coding device according to  claim 12 ,
 wherein, when said coding unit sets the ranges to be searched, said coding unit is configured to set the ranges to be searched so that the number of the ranges to be searched does not exceed the number of reference pictures selected in the case where the coding unit does not determine that the motion amount for the first picture is greater than a predetermined motion amount.   
     
     
         15 . The image coding device according to  claim 12 ,
 wherein said coding unit is configured to set the ranges to be searched in a reference picture which is of same parity as the parity of the first picture, the reference picture being included in the one or more reference pictures.   
     
     
         16 . The image coding device according to  claim 11 ,
 wherein, in the case where said coding unit determines that a motion amount for the first picture is greater than a predetermined motion amount, said coding unit is configured to select, as a reference picture, a picture included in a frame to be coded before or after the first picture, and code the first picture.   
     
     
         17 . The image coding device according to  claim 11 ,
 wherein, when said coding unit codes input image data captured by zooming or panning of a camera, said coding unit is configured to determine that a motion amount for a picture included in the input image data is greater than a predetermined amount.   
     
     
         18 . The image coding device according to  claim 11 ,
 wherein said coding unit is configured to obtain, as the motion amount, an absolute value of a difference between frames included in the input image data.   
     
     
         19 . The image coding device according to  claim 11 ,
 wherein said coding unit is configured to obtain, as the motion amount, picture coding information included in coded input image data.   
     
     
         20 . The image coding device according to  claim 19 ,
 wherein the motion amount is motion vector information applied to each macroblock of a picture included in the input image data.   
     
     
         21 . An image coding method, comprising:
 receiving input image data having an interlace structure;   coding a first picture using a coding method compliant with a predetermined moving-picture compression standard, the first picture being a current picture to be coded among pictures included in the input image data;   wherein said coding includes selecting, depending on a motion amount of the first picture, a first number or fewer of reference pictures from (i) a picture included in a same frame as the first picture and being of parity different from parity of the first picture and (ii) a picture included in a frame preceding or following the first picture, the first number being an integer equal to or greater than one, and   in said coding, the first picture is coded using the reference pictures selected in said selecting.   
     
     
         22 . An image coding integrated circuit, comprising:
 an input unit configured to receive input image data having an interlace structure; and   a coding unit configured to code a first picture using a coding method compliant with a predetermined moving-picture compression standard, the first picture being a current picture to be coded among pictures included in the input image data;   wherein said coding unit is configured to   select, depending on a motion amount for the first picture, a first number or fewer of reference pictures from (i) a picture included in a same frame as the first picture and being of parity different from parity of the first picture and (ii) pictures included in a frame preceding or following the first picture, the first number being an integer equal to or greater than one, and   code the first picture using the selected reference pictures.