IIIIIIIH
US006222882B1
(12) United States Patent (io> Patent No.: us 6,222,882 Bi
Lee et al. (45) Date of Patent: Apr. 24,2001
(54) ADAPTIVE MOTION ESTIMATION
METHOD OF A LUMINANCE SIGNAL
(75) Inventors: Shi-hwa Lee; Jae-seob Shin, both of Seoul (KR)
(73) Assignee: Samsung Electronics Co., Ltd., Kyungki-do (KR)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 08/350,141
(22) Filed: Nov. 29, 1994
(30) Foreign Application Priority Data
Jan. 31, 1994 (KR) 94-1752
(51) Int. C I. II04N 7/18
(52) U.S. CI 375/240.16; 375/240.17
(58) Field of Search 348/416, 409,
348/419, 411, 699, 700, 415; 375/240.16,
240.17
(56) References Cited
U.S. PATENT DOCUMENTS
5,157,732 * 10/1992 Ishii 348/699
5,162,907 * 11/1992 Keating et al 348/416
5,361,105 * 11/1994 Iu 348/416
6,097,832 8/2000 Guillotel et al 382/107
FOREIGN PATENT DOCUMENTS
4-196794 7/1992 (JP) .
Correct motion estimation is performed by preventing an adverse effect due to the variation of lighting conditions when a motion estimation is performed in a motion image device. The method for estimating a motion by dividing an image frame represented by a luminance signal into a plurality of predetermined size blocks and detecting the most similar block in a previous frame with a block in a current frame and producing a corresponding movement distance as a motion vector, includes the steps of: producing a mean value of the luminance signal with regard to a block of the current frame; producing a mean value of the luminance signal with regard to a block to which a motion estimation of the previous frame is applied; compensating the luminance signal of the block to which the motion estimation of the previous frame is applied such that the two mean values have the same level; and selecting a block having the minimum sum of differences between luminance signals of each pixel, with regard to the block of the current frame and the block to which a motion estimation of the previous frame is applied, and producing the movement distance between these as a motion vector. Thus, a correct motion estimation can be made even when the light source is varied or a luminance signal is varied due to the moving of an object.
2 Claims, 6 Drawing Sheets