Inter frame

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

Method and system for a highly efficient low bit rate video codec

Abstract: A system and a method for wavelet-based low bitrate video coding is provided. The system and method of this invention processes each frame of a video sequence based on its content. The discrete wavelet transform of each frame is taken separately. If the difference between the contents of a first frame and a second frame is above a threshold, then the wavelet transformed second frame is quantized and lossless encoded. If the difference is less than a threshold, then motion estimation is employed in wavelet domain. Then the difference between the wavelet transformed second frame and the motion compensated wavelet transformed second frame is quantized and lossless encoded. The quantization is applied by using dynamic adjustment. The quantization tables are optimized based on the coded frame characteristics. In addition to the coded frames, the lossless coded motion vectors are also transmitted to the decoder unit. To improve the quality of the coded video sequence another decision criteria is used at the feedback loop of this invention. The coded second frame is decoded and compared with the original second frame. If the difference between the two frames is above a threshold, then the wavelet transformed second frame is quantized and lossless encoded instead of the motion compensated second frame.

A finite-state vector quantizer for low-rate image sequence coding

Abstract: Vector quantization (VQ) is an effective spatial domain image coding technique at under 1.0 bits per pixel (bpp). Its performance can be improved by incorporating block-to-block memory. Finite State VQs (FSVQ) do this by using a state variable to express characteristics of neighboring blocks and identify which subset of a supercodebook the FSVQ encoder and decoder are to use for the current vector. This paper describes a new method for image sequence coding that uses an interframe FSVQ In the spatial domain. Block-to-block and frame-to-frame memory is expressed through a state which is a function of block motion and the intensity gradients of a block's neighbors. A scalar predictor adds additional interframe memory and reduces the energy of residuals encoded by the VQ, improving edge rendition and limiting blocking artifacts. The codec at 0.6 bpp outperforms a similar, non-finite state intraframe VQ at 1.0 bpp. No motion compensation or conditional replenishment is used.

Apparatus and method for encoding and decoding digital video data

Abstract: Digital video data encoder and decoder operate to enable the low and high speed reproduction of variable rate encoded digital video data by reproducing and decoding intraframe encoded frames that are identified by previously reproduced intraframe encoded frames. In the encoder, digital video data is variable rate encoded, for example, intraframe and interframe encoded, entry points (i.e., beginning positions) of selected encoded video data are identified and which represent video frames that occur at predetermined intervals of time (e.g., 1, 2 and 4 seconds) in the video picture. Entry point data that identify these positions are generated and added to the encoded video data before the video data is recorded on a record medium. When the encoded data is reproduced from the record medium, the entry point data is extracted therefrom and stored, and a successive intraframe encoded frame identified by the extracted entry point data is reproduced and decoded. The invention further provides for a record medium having thereon the encoded digital video data, and also provides for an encoder and corresponding decoder which encode and decode, respectively, digital still image and audio data in which entry points refer to each of the still images and also to particular intervals of time of the audio data.

Adaptive frame rate modulation system and method thereof

Abstract: An adaptive frame rate modulation system and method thereof are described. A frame processing unit is employed to receive a first frame and a second frame for dividing the second frame into a plurality of second block frames. A frame change detection unit compares the first block frames with the second block frames correspondingly for detecting the change status between the first and second frames. A timing generator classifies the second block frames of the second frame to construct a plurality of frame rates based on the compared results of the first and second block frames. The timing generator further modulates the frame rates of the second frames.

Detecting video frame-rate up-conversion based on periodic properties of inter-frame similarity

Abstract: Video frame-rate up-conversion is one of the common operations for tampering digital videos in the temporal domain, such as creating fake high-quality videos and splicing two video clips with different frame rates. However, few existing works have been proposed for detecting this form of tampering operation. Based on the analysis of extensive experiments, we found that frame-rate up-conversion algorithms employed in most current video editing softwares will inevitably introduce some periodic artifacts into inter-frame similarity in the resulting video frame sequence. By analyzing such artifacts, we propose a simple yet very effective method to expose video after frame-rate up-conversion, and further estimate its original frame rate. The experimental results evaluated on 100 original videos at different frame rates have shown the effectiveness of the proposed method. The average detection accuracy can achieve as high as 99 % on noise-free videos in uncompressed and H.264/AVC formats. Besides, the proposed method is robust to noise as the detection accuracy could reach over 85 % and 95 % on noised videos with Gaussian white noise when SNR is 33 db and 36 db respectively.