Motion estimation method and apparatus for calculating a motion vector

A motion estimation apparatus for calculating a motion vector to estimate a current picture partially forming a moving picture on the basis of a reference picture partially forming said moving picture, said current picture including a current block defined by a plurality of pel values, said reference picture including a plurality of search windows each defined by a plurality of pel values, each of said search window having a plurality of candidate blocks each equal in size to said current block, and said motion vector being indicative of a displacement between said current block and one of said candidate blocks most similar to said current block, comprising:

• search window supplying means for supplying the pel values of said search windows;
• current block supplying means for supplying the pel values of said current block;
• a register group formed by a plurality of first and second registers for receiving and holding the pel values of one of said search windows;
• an arithmetic group formed by a plurality of arithmetic devices equal in number to said first registers, each of said arithmetic devices receiving the pel values of one of said search window from said first registers and receiving the pel values of said current block to calculate each of distortion values indicative of a difference between said current block and each of said candidate blocks;
• search window selecting means for selecting one from among said search windows;
• first instructing means for instructing said search window supplying means to supply said register group with the pel values of the search window selected by said selecting means;
• second instructing means for instructing said current block supplying means to supply said arithmetic group with the pel values of said current block;
• selecting means for selecting part of said first and second registers on the basis of the search window selected by said search window selecting means;
• third instructing means for instructing the selected first and second registers to shift the pel values of said search window therebetween;
• fourth instructing means for instructing the arithmetic devices to calculate said distortion values, respectively, on the basis of the received pel values of the candidate blocks of said selected search window received from the selected first registers and the received pel values of said current block;
• and
• detecting means for detecting the minimum distortion value from among said calculated distortion values to specify the candidate block of the select search window most similar to said current block.

A motion estimation apparatus for calculating a motion vector to estimate a current picture partially forming a moving picture on the basis of a reference picture partially forming said moving picture, said current picture being partially formed by a current block containing N.times.M pel values which are arranged in the form of a matrix with N rows by M columns, said reference picture being partially formed by first and second search windows containing H1.times.L1 pel values and H2.times.L2 pel values, respectively, which are arranged in the form of a matrix with H1 rows by L1 columns and H2 rows by L2 columns, respectively, said first and second search windows each having a plurality of candidate blocks each equal in size to said current block, said N and M being integers, respectively, and said H1 and L1 being integers greater than said N and M, respectively, said H2 and L2 being integers greater than said N and M, respectively, and smaller than said H1 and L1, said motion estimation apparatus assuming two different operation modes consisting of a first operation mode in which said apparatus calculates a motion vector indicative of a displacement between said current block and one of the candidate blocks of said first search window most similar to said current block, and a second operation mode in which said apparatus calculates a motion vector indicative of a displacement between said current block and one of the candidate blocks of said second search window most similar to said current block, comprising:

• a plurality of processor elements for receiving and holding the pel values of said search window and for receiving the pel values of said current block to calculate distortion values each indicative of a difference between said current block and each of said candidate blocks, the number of said processor elements being equal to the number of said candidate blocks included in said second search window;
• a plurality of intermediate registers for receiving and holding the pel values of said search window, the sum of the number of said processor elements and the number of said intermediate registers being (H1-N+1).times.(L1-M+1), said processor elements and said intermediate registers respectively forming (H1-N+1).times.(L1-M+1) matrix elements arranged in the form of a matrix array with (H1-N+1) rows by (L1-M+1) columns;
• (L1-M+1) side register units for receiving and holding the pel values of said search window, said (L1-M+1) side register units being related to at least one of each of the (L1-M+1) matrix elements of the 1st row and each of the (L1-M+1) matrix elements of the (H1-N+1)th row, the side register unit related to the matrix element of the lth column of said matrix array being assumed to be a side register unit of the lth column, and said l being an integer defined by 1.ltoreq.l.ltoreq.(L1-M+1);
• mode selecting means for selecting one of said first and second operation modes, all of the columns and rows of said matrix array being counted as columns and rows of a matrix array for said first search window when said first operation mode is selected, part of the columns and the rows of said matrix array including at least one processor element are counted as columns and rows of a matrix array for said second search window when said second operation mode is selected;
• an input register unit for receiving and holding the pel values of said selected search window, said input register unit being electrically connected to the side register unit of the (L1-M+1)th column of said first or matrix array and the matrix elements of the (L1-M+1)th column of said matrix array;
• search window supplying means for supplying the pel values of said first search window to said input register unit when said first operation mode is selected, and for supplying the pel values of said second search window to said input register unit when said second operation mode is selected;
• current block supplying means for supplying the pel values of said current block into said processor elements;
• transmission control means for repeatedly transmitting H1 or H2 pel values of said first or second search window from said input register unit to the matrix elements and side register unit of the (L1-M+1)th column until all of the pel values of said first or second search window are received by the matrix elements and the side register unit of the (L1-M+1)th column;
• first shift control means for parallel shifting the pel values from the matrix elements of the lth column of said matrix array to the matrix elements of the (l-1)th column of said matrix array and from the side register unit of the lth column of said matrix array to the side register unit of the (l-1)th column in simultaneous relationship to each of the repetitions by said transmission control means, said first shift control means being operated on assumption that all of the rows and columns of said matrix array are counted as columns of said matrix array when said first operation mode is selected, and that the rows and columns of said matrix array each including at least one processor element are counted as columns of said matrix array when said second operation mode is selected;
• second shift control means for parallel shifting, (N-1) times in each of said intervals, the pel values from the side register units of the odd columns to the matrix elements occupying intersections of the odd columns and the 1st row of said matrix array, from the matrix elements occupying intersections of the odd columns and the hth row of said matrix array to the matrix elements occupying intersections of the odd columns and the (h+1)th row of said matrix array, and from the matrix elements occupying intersections of the odd columns and the (H1-N+1)th row of said matrix array to the side register units of the odd columns, said h being an integer defined by 1.ltoreq.h<(H1-N+1), said second shift control means being operated on assumption that the columns of said matrix array including at least one processor element and all of the rows of said matrix array are counted as columns and rows of said matrix array when said first operation mode is selected, and that the rows and columns of said matrix array each including as least one processor element are counted as rows and columns of said matrix array when said second operation mode is selected;
• third shift control means for parallel shifting, (N-1) times in each of said intervals, the pel values from the side register units of the even columns to the matrix elements occupying intersections of the even columns and the (H1-N+1)th row of said matrix array, from the matrix elements occupying intersections of the even columns and the (h+1)th row of said matrix array to the matrix elements occupying intersections of the even columns and the hth row of said matrix array, and from the matrix elements occupying intersections of the even columns and the 1st row of said matrix array to the side register units of the even columns, said third shift control means being operated on assumption that the columns of said matrix array including at least one processor element and all of the rows of said matrix array are counted as columns and rows of said matrix array when said first operation mode is selected, and that the rows and columns of said matrix array each including as least one processor element are counted as rows and columns of said matrix array when said second operation mode is selected;
• odd column input control means for instructing said current block supplying means to input the pel values of said current block into the processor elements of the odd columns of said matrix array in first predetermined order simultaneously when the pel values of each of said candidate blocks are received by each of said processor elements;
• even column input control means for instructing said current block supplying means to input the pel values of said current block into the processor elements of the even columns of said matrix array in second predetermined order different from said first predetermined order simultaneously when the pel values of said candidate blocks are received by each of said processor elements;
• and
• calculation control means for instructing each of said processor elements to calculate each of the distortion values on the basis of the received pel values of each of said candidate blocks of said first search window and the received pel values of said current block when said first operation mode is selected by said mode selecting means, and for instructing each of said processor elements to calculate each of the distortion values on the basis of the received pel values of each of said candidate blocks of said second search window and the received pel values of said current block when said second operation mode is selected by said mode selecting means.