A method of decoding a bitstream comprising an encoded sequence of digital images, at least one portion of an image being encoded by motion compensation with respect to a reference image, the method comprising: obtaining (S502; S602, S604) for an image portion to be decoded, motion information predictors as motion information predictor candidates wherein the motion information predictors are actual motion information predictors, having motion vectors obtained from image portions of said image being decoded or of a reference image; testing (S512; S606) whether the number (N; N1) of motion information predictor candidates is lower than a target number (Nmax) and, if so, adding (S608, S610) one or more motion information predictors in a predetermined order as motion information predictor candidates to generate a set of motion information predictor candidates different from one another, said set having a number of motion information predictor candidates equal to the target number; decoding an item of information representative of a selected motion information predictor for said image portion to be decoded; and determining the selected motion information predictor for decoding motion information of said image portion to be decoded using the generated set of motion information predictor candidates, potential motion information predictors for addition include one or more further such actual motion information predictors and also include one or more virtual motion information predictors not having motion vectors obtained from image portions of said image being decoded or of a reference image; and characterized in that: the adding (S608, S610) of one or more motion information predictors comprises: performing a first adding process of adding (S608, S610) one or more said further actual motion information predictors; and making a second test whether the number of motion information predictor candidates is lower than said target number (Nmax) and, if so, performing a second adding process of adding (S618-S626) one or more said virtual motion information predictors as motion information predictor candidates. obtaining (S502; S602, S604) for an image portion to be decoded, motion information predictors as motion information predictor candidates wherein the motion information predictors are actual motion information predictors, having motion vectors obtained from image portions of said image being decoded or of a reference image; testing (S512; S606) whether the number (N; N1) of motion information predictor candidates is lower than a target number (Nmax) and, if so, adding (S608, S610) one or more motion information predictors in a predetermined order as motion information predictor candidates to generate a set of motion information predictor candidates different from one another, said set having a number of motion information predictor candidates equal to the target number; decoding an item of information representative of a selected motion information predictor for said image portion to be decoded; and determining the selected motion information predictor for decoding motion information of said image portion to be decoded using the generated set of motion information predictor candidates, potential motion information predictors for addition include one or more further such actual motion information predictors and also include one or more virtual motion information predictors not having motion vectors obtained from image portions of said image being decoded or of a reference image; and characterized in that: the adding (S608, S610) of one or more motion information predictors comprises: performing a first adding process of adding (S608, S610) one or more said further actual motion information predictors; and making a second test whether the number of motion information predictor candidates is lower than said target number (Nmax) and, if so, performing a second adding process of adding (S618-S626) one or more said virtual motion information predictors as motion information predictor candidates. performing a first adding process of adding (S608, S610) one or more said further actual motion information predictors; and making a second test whether the number of motion information predictor candidates is lower than said target number (Nmax) and, if so, performing a second adding process of adding (S618-S626) one or more said virtual motion information predictors as motion information predictor candidates.