Inter frame

About: Inter frame is a research topic. Over the lifetime, 4154 publications have been published within this topic receiving 63549 citations.

Motion-Compensated Frame Rate Up-Conversion—Part I: Fast Multi-Frame Motion Estimation

Abstract: Motion-compensated frame rate up-conversion is used to convert video/film materials of low frame rates to a higher frame rate so that the materials can be displayed with smooth motion and high-perceived quality. It consists of two key elements: motion estimation and motion-compensated frame interpolation. It requires accurate motion trajectories to ensure quality results and low computational cost to ensure practical applications. This paper presents a novel motion estimation algorithm that combines the accuracy of maximum a posteriori probability (MAP) estimation with the speed of hierarchical block-matching algorithm (BMA). This MAP estimation uses three consecutive pictures, instead of the conventional two, and one previously estimated motion field to exploit the temporal correlation between motion fields and to determine motion in occluded areas. The optimization of the MAP estimation is performed using full-search and implemented by means of look-up tables. The full search ensures that the optimization converges to the global minimum, while the look-up tables dramatically reduce the computational cost. Experimental results show that the proposed algorithm provides motion trajectories that are much more accurate than those obtained using either the full-search BMA or hierarchical BMA alone. Also, it is much faster than the full-search BMA.

Optimal motion vector accuracy for block-based motion-compensated video coders

Abstract: In block-based motion-compensated video coding, a fixed-resolution motion field with one motion vector per image block is used to improve the prediction of the frame to be coded. All motion vectors are encoded with the same fixed accuracy, typically 1 or 1/2 pixel accuracy. In this work, we explore the benefits of encoding the motion vectors with other accuracies, and of encoding different motion vectors with different accuracies within the same frame. To do this, we analytically model the effect of motion vector accuracy and derive expressions for the encoding rates for both motion vectors and difference frames, in terms of the accuracies. Minimizing these expressions leads to simple formulas that indicate how accurately to encode the motion vectors in a classical block-based motion-compensated video coder. These formulas also show that the motion vectors must be encoded more accurately where more texture is present, and less accurately when there is much interframe noise. We implement video coders based on our analysis and present experimental results on real video frames. These results suggest that our equations are accurate, and that significant bit rate savings can be achieved when our optimal motion vector accuracies are used.

Predictive video encoding using measured subject velocity

Abstract: In an encoding system for use with video signals, the velocity of a subject between two frames is estimated and used to predict the location of the subject in a succeeding frame. Differential encoding between this prediction and the actual succeeding frame are used to update the prediction at the receiver. As only the velocity and the updating difference information need be transmitted, this provides a reduction in the communication channel capacity required for video transmission. The scheme may be implemented by comparing the intensities of points in consecutive frames, identifying those points having a significant frame to frame intensity difference as part of the moving subject, determining an estimated velocity of the identified subject, predicting the present frame by translating a portion of the previous frame by the estimated velocity (the translated portion forming the identified subject), and transmitting the updating difference between the actual and predicted present frames along with the predictive velocity information.

Data compression method and apparatus in which quantizing bits are allocated to a block in a present frame in response to the block in a past frame

Abstract: A digital input signal is compressed to provide a compressed output signal in a manner which prevents pre-echo, a common defect of data compressors The digital input signal is divided in time into frames, and into at least one block of data in each frame The frames include a past frame preceding a present frame Block floating is applied to the data in the block in each frame Quantizing bits are adaptively allocated to the data in the block in the present frame in response to the block in the past frame Finally, the resulting quantized data is added to the compressed output signal In a first variation, a signal energy or an allowable noise level is determined for the block in each frame A word length is determined for the block in each frame in response to the determined signal energy or allowable noise level of the block The quantizing bits are allocated to the data in the block in the present frame in response to the word length for the block in the past frame In a second variation, a signal energy in the block in each frame is determined, and quantizing bits are adaptively allocated to the data in the block in the present frame in response to an interpolation between the signal energy for the block in the present frame and for the block in the past frame

Apparatus and method of converting frame and/or field rate using adaptive motion compensation

Abstract: An apparatus and method which includes estimating a motion vector of a frame and/or field to be interpolated and the accuracy of the motion vector using motion vectors of previous and next frames and/or fields; determining motion information by analyzing the estimated motion vector, and calculating a correlation between the motion vector of the current block and the motion vectors of neighboring blocks; generating pixels to be interpolated by performing motion compensation in a frame and/or field to be interpolated using the estimated motion vector and using pixels neighboring a pixel to be interpolated in the frame and/or field to be interpolated and pixels neighboring a pixel to be interpolated in the previous and next frame and/or field of the pixel to be interpolated; and outputting the generated pixels as interpolation values according to the accuracy of the estimated motion vector, the motion information, and the correlation.