What is motion compensation and estimation?
Motion estimation examines the movement of objects in an image sequence to try to obtain vectors representing the estimated motion. Motion compensation uses the knowledge of object motion so obtained to achieve data compression. Such motion is difficult to estimate and may require large amounts of processing.
What is motion estimation techniques?
Motion estimation is the process of determining motion vectors that describe the transformation from one 2D image to another; usually from adjacent frames in a video sequence. It is an ill-posed problem as the motion is in three dimensions but the images are a projection of the 3D scene onto a 2D plane.
What is motion compensation and motion estimation in video compression?
Motion compensation is an algorithmic technique used to predict a frame in a video, given the previous and/or future frames by accounting for motion of the camera and/or objects in the video. It is employed in the encoding of video data for video compression, for example in the generation of MPEG-2 files.
What is block based motion estimation?
A Block Matching Algorithm is a way of locating matching macroblocks in a sequence of digital video frames for the purposes of motion estimation. This movement, calculated for all the macroblocks comprising a frame, constitutes the motion estimated in a frame.
What is half pixel accuracy motion estimation state the reasons behind using this method in motion estimation in MPEG 1 video standard?
1.2. MPEG-1 allows half-pixel accuracy motion vectors. By estimating the displacement at a finer resolution, we can expect improved prediction and, thus, better performance than motion estimation with integer pixel accuracy.
What is multi resolution motion estimation?
Motion estimation is an important aspect for image sequence analysis, which is part of image sequence coding. Within the pyramid motion estimation is done top-down by matching each pixel, which results in a multiresolution motion vector field.
Why is motion estimation necessary in video compression?
The motion estimation block determines the displacement between the current frame and the stored frame. From the second frame onwards, both temporal as well as spatial redundancy can be exploited. Since these frames use inter-frame redundancy for data compression, these are referred to as inter-coded frames.
What is motion vector in video compression?
In video compression, a motion vector is the key element in the motion estimation process. It is used to represent a macroblock in a picture based on the position of this macroblock (or a similar one) in another picture, called the reference picture.
What is motion compensation VR?
Motion compensation is a feature that helps smooth frame rates in VR applications for a more seamless visual experience.
What is the main reason behind use of quarter pixel precision in motion compensation in H 264?
All motion vectors in H. 264/AVC are transmitted with quarter luma sample accuracy, providing improved opportunities for prediction compared to most previous standards, which allowed only half-sample accurate motion compensation.
What is the search window in motion estimation?
search window and of the associated search strategy are critical for a motion estimation algorithm. Figure 8 – Left: the current image with the block B p,q highlighted. Right: the reference image. The search window centered in (p,q)is shown. 6.1.1. Full search
Is there a diamond search algorithm for block matching motion estimation?
A new diamond search algorithm for fast block-matching motion estimation, IEEE Trans. on Image Processing (2000), 9 (2), pp. 287 – 290.
Is there an estimation-theoretic analysis of motion compensation?
An estimation-theoretic analysis of motion compensation is presented in (Orchard and Sullivan, 1994). OBMC is formulated as a probabilistic linear estimator of pixel intensities, which leads to improved prediction.
How to estimate motion in video coding?
4 Pel-recursive approaches Pel-recursive approaches are among the earliest methods to estimate motion with the objective of video coding applications. Essentially, these techniques recursively estimate the displacement which minimizes the Displaced Frame Difference (DFD) defined as