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Showing papers on "Run-length encoding published in 1993"


Patent
21 Dec 1993
TL;DR: In this article, a method for compressing video movie data to a specified target size using intra-frame and inter-frame compression schemes is proposed. But the method does not consider the quality of the original video data.
Abstract: A method for compressing video movie data to a specified target size using intraframe and interframe compression schemes. In intraframe compression, a frame of the movie is compressed by comparing adjacent pixels within the same frame. In contrast, interframe compression compresses by comparing similarly situated pixels of adjacent frames. The method begins by compressing the first frame of the video movie using intraframe compression. The first stage of the intraframe compression process does not degrade the quality of the original data, e.g., the method uses run length encoding based on the pixels' color values to compress the video data. However, in circumstances where lossless compression is not sufficient, the method utilizes a threshold value, or tolerance, to achieve further compression. In these cases, if the color variance between pixels is less than or equal to the tolerance, the method will encode the two pixels using a single color value--otherwise, the method will encode the two pixels using different color values. The method increases or decreases the tolerance to achieve compression within the target range. In cases where compression within the target range results in an image of unacceptable quality, the method will split the raw data in half and compress each portion of data separately. Frames after the first frame are generally compressed using a combination of intraframe and interframe compression. Additionally, the method periodically encodes frames using intraframe compression only in order to enhance random frame access.

140 citations


Patent
26 May 1993
TL;DR: In this paper, a video processor system has separate and independent video processors for performing a variety of video processor functions required for encoding and decoding video signals, each of the separate video processors performs its own individual set of video processors functions.
Abstract: A video processor system has separate and independent video processors for performing a variety of video processor functions required for encoding and decoding video signals. Each of the separate video processors performs its own individual set of video processor functions. During the encode process the first video processor performs motion estimation to provide motion estimation information which it applies to the second video processor. The second video processor receives the motion estimation information and performs forward and inverse discrete cosine transforms, quantization and dequantization, frame addition and frame differencing, as well as run length encoding. The run length encoding operation produces run/value pairs which are then applied to the first video processor. The first video processor performs variable length encoding upon the run/value pairs. During the decoding process the first video processor performs a variable length decode and applies the variable length decoded data to the second video processor. The second video processor performs run length decoding, dequantization, inverse discrete cosine transforms and frame addition according to the received variable length data. The inverse transformed data produced by this operation is then applied to the first video processor.

34 citations


Patent
15 Jun 1993
TL;DR: In this paper, the Sequence Control Byte (SCB) is modified to communicate indications to a receiver that the compression mode of 1 to N bytes per character is being changed and to indicate what the change is or that a con, non master repeat character frequently encountered in data is being reefined to be another character or that characters are going to be encoded in multiple bytes.
Abstract: Improvements are made to standard run length encoding compression techniques to permit frequently occurring repeated bytes to be dynamically redefined or reset to a default value such as a blank character, repeated multiple byte units or strings to be more efficiently coded and run length encoded enhancements allow compression of data where characters are represented by multiple bytes. The Sequence Control Byte (SCB) is modified to communicate indications to a receiver that the compression mode of 1 to N bytes per character is being changed and to indicate what the change is or that a con, non master repeat character frequently encountered in data is being redefined to be another character or that characters are going to be encoded in multiple bytes. The SCB format which is well known in the prior art is modified to include specific bit patterns or codes in the first two bits of the SCB byte to indicate setting of the bytes per character encoding mode to a different value, resetting the encoding mode to a default value or redefining a commonly repeated character or defining a character to be multiple bytes or a string of characters which may be multiple byte characters. The other six bits of the SCB are assigned code values unused in the prior art to indicate the number of tines that a defined character is to be repeated, whether a master character that has been defined is to be repeated or whether a character string is to be repeated. Two fields of data are thus formatted in the SCB with new values to indicate to a receiver these new criteria.

20 citations


Journal ArticleDOI
TL;DR: This paper presents a non-iterative line thinning method that preserves X-crossings of the lines in the image via a histogram analysis of the lengths of runs, and intersections are detected at locations where the sequences of runs merge or split.
Abstract: For an image consisting of wire-like patterns, skeletonization (thinning) is often necessary as the first step towards feature extraction. But a serious problem which exists is that the intersections of the lines (X-crossings) will be elongated when applying a thinning algorithm to the image. That is, X-crossings are usually difficult to be preserved as the result of thinning. In this paper, we present a non-iterative line thinning method that preserves X-crossings of the lines in the image. The skeleton is formed by the mid-points of run-length encoding of the patterns. Line intersection areas are identified via a histogram analysis of the lengths of runs, and intersections are detected at locations where the sequences of runs merge or split.

12 citations


Patent
14 Jan 1993
TL;DR: In this paper, a data train A to be compressed is successively read for each character (high-order byte) and compared, the codes of the continuous characters and the number of continuous characters are recorded together with a special character showing the compression, and preprocessing data B of compression are prepared.
Abstract: PURPOSE:To efficiently compress Japanese data composed of two byte codes according to a run length encoding system by executing the preprocessing of compression to compress continuous character strings at every two strings. CONSTITUTION:In the preprocessing of compression, a data train A to be compressed is successively read for each character (high-order byte) and compared, the codes of the continuous characters and the number of continuous characters are recorded together with a special character showing the compression, and preprocessing data B of compression are prepared. Next, compressed data C are prepared by compressing low-order bytes. Thus, compressibility can be improved in comparison with data C' compressed by normal run length encoding.

2 citations