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| | [No title] |
 | | The length of the original run is then calculated as 2^(N-2)+V+1 where N is the length of the encoded run and V is the value of the variable length code. | | | The size of the variable length code is N-2 bits where N is the length of the encoded run. | | | This new run length is calculated as N+2 where N is the number of bits in the variable length code as calculated above. |
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http://www.geocities.com/m99datacompression/papers/rle2.html
(1172 words)
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| | RLE - Run length Encoding |
| | Run length encoding is a straightforward way of encoding data so that it takes up less space. | | | Run length encoding is used within a number of image formats, for example PNG, TIFF, and TGA. | | | For example, there is no way in the above encoding to encode strings with numbers, that is, how would one know whether the number was the length of the run or part of the string content. |
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http://astronomy.swin.edu.au/~pbourke/dataformats/rle
(745 words)
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| | Run-Length Encoding (RLE) |
| | Another seldom-encountered RLE variant is a lossy run-length encoding algorithm. | | | The parts of run-length encoding algorithms that differ are the decisions that are made based on the type of data being decoded (such as the length of data runs). | | | A run of image data stored as 3-byte pixel values encodes to a 4-byte packet, with one run-count byte followed by three run-value bytes (shown in Figure 9-4, e). |
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http://www.fileformat.info/mirror/egff/ch09_03.htm
(2837 words)
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| | [No title] |
| | The counter in Run Length Encoder 560 is then reset to a value 1, contemporaneous with which the MHC of the encountered non-zero value from LUTs 540 is output to compressed/encoded data 570 such that the MHC follows the structures (F, R) output by Run Length Encoder 560. | | | Such encoding is inefficient where the number of zeroes greatly outweigh the non-zero, and especially where such zero data values are consecutive, creating a large"run"of zeroes in binary. | | | The inability to tune the binary encoding process to the characteristic of the data set (or subset of the data set), may result in overall compression ratios that are not optimal. |
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http://www.wipo.int/cgi-pct/guest/getbykey5?KEY=00/02319.000113&ELEMENT_SET=DECL
(7991 words)
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| | RLE (Run Length Encoding) Compression Algorithm |
| | Encoding: search two byte of the same value and put a value of how many byte of the same value occur again, even no more is found it is still required to put zero value indicating no more is found. | | | My implemetation and source for RLE can be found in tools section, please download it and play with it, but remember in my RLE program I used the value of 4 instead of 2 (example above) as the minimum repeatition, I do this because the minimum value of 4 have a better result (normally). | | | Decoding: whenever we found two same charactera in a row it means the next byte value is the value of how many more repeatition occur. |
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http://www.geocities.com/hmaxf_urlcr/rle.htm
(276 words)
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| | Run-length encoding - Wikipedia, the free encyclopedia |
| | Run-length encoding (RLE) is a very simple form of data compression in which runs of data (that is, sequences in which the same data value occurs in many consecutive data elements) are stored as a single data value and count, rather than as the original run. | | | Common formats for run-length encoded data include PackBits, PCX and ILBM. | | | This is most useful on data that contains many such runs; for example, simple graphic images such as icons and line drawings. |
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http://en.wikipedia.org/wiki/Run-length_encoding
(381 words)
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| | Run-length encoding - Computing Reference - eLook.org |
| | A kind of compression algorithm which replaces sequences ("runs") of consecutive repeated characters (or other units of data) with a single character and the length of the run. | | | This technique is particularly useful for encoding black and white images where the data units would be single bit pixels. | | | This can either be applied to all input characters, including runs of length one, or a special character can be used to introduce a run-length encoded group. |
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http://www.elook.org/computing/run-length-encoding.htm
(91 words)
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| | GameDev.net - 16-bit RLE Compression |
| | Run Length Encoding, also known as RLE, is a method of compressing data that has a lot of "runs" of bytes (or bits) in it. | | | However, if the text to be encoded is arbitrary, then it may contain numbers as well as letters, and bytes of all possible values. | | | In 8 bit version, when encoder reaches max run length, it is written out correctly, but is followed by a 1 length run of the next byte. |
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http://www.gamedev.net/reference/articles/article290.asp
(535 words)
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| | Pointless Database - RLE (Run Length Encoding) |
| | RLE stands for run length encoding and is a form of data compression used primarily for storing graphic data on computers. | | | RLE works by takings long strings of similar data and storing only one piece of it as well as the length of it. | | | Because of the way this compression algorithm works, it is very poor for storing documents, programs, or photographs, but it works very well for storing computer screenshots because they often have long runs of pixels of the same color. |
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http://www.thealmightyguru.com/Database/DB-RLE.html
(154 words)
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| | CS 352 Fall 2003 Project Specification Part 2: Encoding and Rate Control |
| | In the RLE encoding scheme, these pixels would be represented by a 2 byte count (2500) and a 3 byte value (255,255,255) for a total number of 5 bytes. | | | In the encoding scheme in part 1, this data would repeat the RGB values of 255,255,255 for 50 x 50 or 2500 times, sending a total of 7500 bytes into the network. | | | As in part 1 of the project, the video data protocol packets follow the following format described in Figure 2, however, the encoding scheme for run length encoding is specified as a the ``number 2'' in 16-bit big-endian format in the encoding field. |
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http://remus.rutgers.edu/cs352/F03/project/part2
(2921 words)
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| | The RLE compression algorithm |
| | RLE is probably the easiest compression algorithm there is. It replaces sequences of the same data values within a file by a count number and a single value. | | | RLE compression is only efficient with files that contain lots of repetitive data. | | | This algorithm is very easy to implement and does not require much CPU horsepower. |
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http://www.prepressure.com/techno/compressionrle.htm
(283 words)
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| | [No title] |
| | As indicated in lines 150-153, the run count is recovered from an input code received by the decompressor 110 by adding the illustrated values to the received code in accordance with the respective received Reserved Code as depicted. | | | If so, the input code represents a run count which is recovered by subtracting the extant code in the Code Counter 123 from the received input code. | | | A special run enhancement engine is utilized at the input to the decompressor to regenerate the missing codes. |
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http://www.wipo.int/cgi-pct/guest/getbykey5?KEY=00/79687.001228&ELEMENT_SET=DECL
(10325 words)
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| | 10.2 Run Length Encoding |
| | Runs are represented with a count and the original data byte. | | | Other image file formats that use run length encoding are RLE and GEM. | | | This variable length coding is the idea behind Huftman coding. |
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http://www.netnam.vn/unescocourse/computervision/102.htm
(564 words)
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| | [No title] |
| | After every run has been returned, nextRun() returns null, which lets the calling program know that there are no more runs in the encoding. | | | One constructs a run-length encoding of an empty ocean, and the other constructs a run-length encoding based on two arrays provided as parameters to the constructor. | | | For a correct encoding, you must separate sharks based on their hunger!) If you are familiar with.GIF image files (often encountered on the Web), you might be interested to know that they use run-length encoding to reduce their sizes. |
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http://www.cs.berkeley.edu/~jrs/61b/hw/pj1/readme
(2935 words)
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| | Run Length Encoding (RLE) Discussion and Implementation |
| | As with my other compression implementations, my intent is to publish an easy to follow ANSI C implementation of a run length encoding (RLE) algorithm. | | | For more information on RLE and other compression algorithms, visit DataCompression.info. | | | The entire library is contained in its own zipped archive which includes the source files and all the necessary build instructions. |
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http://michael.dipperstein.com/rle
(912 words)
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| | Energy Citations Database (ECD) - Energy and Energy-Related Bibliographic Citations |
| | For data strings of 18 bytes or longer, a set offset and an encoded run-length are written to the output buffer and then a run byte is written to the output buffer. | | | Longer data strings are then encoded in one of two ways depending on the length of the string. | | | Data bytes that are not part of data strings of sufficient length are written directly to the output buffer. |
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http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=453526&query_id=0
(269 words)
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| | DataCompression.info - Run Length Encoding/RLE |
| | This is the Assembler code used to compress or decompress some data by modified RLE algorithm. | | | A paper by Michael A. Maniscalco that desribes an RLE algorithm tailored for use with the BWT compression technique. |
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http://datacompression.info/RLE.shtml
(973 words)
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| | [No title] |
| | The following example shows the output file that would be obtained by performing run-length encoding on an input file containing 4 rows by 5 columns of cells. | | | Run-Length Encoding: The file called ELEV.DAT is a raster data file of elevations for Africa. | | | Run the QuickBASIC program called MAPRUN.BAS to display a map of the output file. |
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http://www.ncgia.ucsb.edu/Publications/tech-reports/91/91-14/data/four/assign4.txt
(1240 words)
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| | Run-Length-Limited Encoding Simulation |
| | The RLL encoding of the data is then sent to the magnetic disk using NRZI transmission encoding. | | | Applets might not run on Windows 95 or Mac OS 8 or 9. | | | Applets on this website were written by Teresa Carrigan in 2004, for use in computer science courses at Blackburn College, with the exception of the Fireworks applet. |
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http://www.frontiernet.net/~prof_tcarr/RLL-Encoding
(184 words)
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| | comp.compression Frequently Asked Questions (part 1/3) - [8] What about patents on data compression algorithms? |
| | The first one covers run length encoding in its most primitive form: a length byte followed by the repeated byte. | | | A series of fixed length overlapping segments, called hash strings, are formed from an input data sequence. | | | If a string to be compressed is found in the symbol stream, a code is output designating the location within the search window of the matching string and the length of the matching string. |
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http://www.cd.sc.ehu.es/DOCS/mice/compression-faq/part1/faq-doc-7.html
(2350 words)
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| | Run-length Limited Encoding - RLE |
| | Short for Run-length Limited Encoding, RLE is a type of file format used with computer graphics files to help reduce the overall size of a file. | | | Although a graphics file may end with an extension of.RLE, there are graphic files such as some BMP files and TIFF files that may utilize RLE, but end with their appropriate file extension. | | | Also see our file extension page for addition listings of computer file extensions. |
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http://www.computerhope.com/jargon/r/rle.htm
(82 words)
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| | CPSC 461 Labs 2&3 Data Compression Review Part 2 |
| | Question 7: We want to compress a file using Run Length Enconding but all possible bit strings are used in the data so none are readily available for use as a repetition code. | | | PART B - As the sum of the differences between frequencies approaches zero, varying length codes no longer make sense (ie - when all the frequencies are the same). | | | Most images will have sequential pixel patterns that occur frequently throughout the file. |
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http://pages.cpsc.ucalgary.ca/~gwen/TA/cpsc461/datacomp2.html
(656 words)
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| | What is RLE? - A Word Definition From the Webopedia Computer Dictionary |
| | The file extension for graphics that have been reduced using run-length encoding. | | | It works best with black-and-white or cartoon-style graphics, and is used to compress Windows start-up logos. | | | You are in the: Small Business Computing Channel |
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http://www.webopedia.com/TERM/R/RLE.html
(116 words)
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| | Database Compression |
| | There is always some minimum amount of repetition that must be present when implementing run-length encoding for it to be effective. | | | This is because the compressed version of these strings would be just as long (or longer in the case of DD) than the original string, so there is no use encoding them. | | | - Requires only one run through the data, and is not computationally complex |
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http://www.cs.brown.edu/people/johnny/run.html
(288 words)
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| | Run Length Encoding |
| | A zig-zag scan would further reduce the requirement to 30 bits, using 5 bits for the lengths. | | | Other approaches find the edges of objects and then encode the edges using Fourier descriptors or 8-bit chain codes. | | | )/J then gives the entropy for the entire binary image using run length coding as |
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http://www.marquette.edu/~matthysd/web226/L0425.htm
(353 words)
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| | Run-Length Coding |
| | With RLE, this would only require two bytes to store, the count (15) is stored as the first byte and the symbol (A) as the second byte. | | | Run-length encoding is supported by most bitmap file formats such as TIFF, BMP and PCX. | | | RLE cannot acheive high compression ratios compared to other compression methods, but it is easy to implement and is quick to execute. |
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http://www.eee.bham.ac.uk/WoolleySI/All7/run_1.htm
(163 words)
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| | Lecture 15 |
| | Because the longest run you could represent would be represented by the hex digit FF, and it would take up 3 bytes to represent this code. | | | The blanks in the data are NOT to be encoded; they are simply inserted to make it easier for you to read and count characters. | | | SUMMARY: If I gave you a series of numbers (of some length n which is a power of 2), you could compute its Walsh transform, and vice versa. |
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http://longwood.cs.ucf.edu/~moshell/IDS2680/lecture15.html
(3100 words)
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| | Articles - Run Length Limited |
| | RLL encoding was invented by IBM engineers, who used it in mainframe disk drives. | | | The length of time usually expressed in channel bits between consecutive transitions 0 to 1 or 1 to 0 is known as the runlength. | | | Run Length Limited codes, or RLL codes are widely used in hard disk drives and notably digital optical discs, such as CD, DVD and BluRay disc. |
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http://www.digital-voicerecorders.net/articles/Run_Length_Limited
(280 words)
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| | DDJ>MAY89: RUN LENGTH ENCODING REVISITED |
| | What brought this all to mind was the RLE presented in Robert Zigon's "Run Length Encoding" (DDJ, February 1989). | | | Every byte in the file is marked as either "compressed" or "uncompressed." The markers (or "compression bytes") are 1 byte in size. | | | A compression byte has the high bit set if it indicates a run of redundant bytes, and clear if it marks a set of unique bytes. |
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http://www.ddj.com/documents/s=1090/ddj8905f/8905f.htm
(848 words)
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| | Notes From The Comp.Compression FAQ |
| | The second patent covers limiting the run length to 16 bytes and thus the encoding of the length on 4 bits. | | | The first one covers run length encoding in its most primitive form: a length byte followed by the repeated byte. | | | Notenboom (from Microsoft US Patent 4955066) uses three levels of compression, starting with run length encoding. |
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http://www.ross.net/compression/patents_notes_from_ccfaq.html
(1001 words)
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| | RLE - Run Length Encoding |
| | Run Length Encoding is a lossless compression format primarily used with Windows files (BMP, PCX). | | | More information about the definition of RLE may appear below: | | | RLE is also known as Animation, and was created specifically for compression and decompression of animation clips. |
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http://www.auditmypc.com/acronym/RLE.asp
(236 words)
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| | Two Dimensional RRLE (Rectangle/Run Length Encoding) |
| | With this new flexibility, longer runs which change directions can be encoded more efficiently. | | | RRLE also encodes rectangles of equal values where they exist. | | | As the algorithm will show, however, the best compression can be achieved when the two work together. |
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http://www.cs.unc.edu/~hinson/comp249
(258 words)
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| | Lab 11: Loop invariants |
| | Thus, if a bitmap has a 1 as the first bit, then the first number stored in the run-length encoding file will be 0 (since there are no zeros initially). | | | For example, the bitmap image above of the < symbol begins with five 0's, then two 1's, then five 0's, then two 1's, etc. The entire file is represented in compressed form using run-length encoding by the following: | | | When run-length encoding is used, the number of consecutive 0's is counted, then the number of consecutive 1's, then 0's, and so on. |
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http://www.cs.duke.edu/courses/cps006/fall04/labs/lab11/lab.html
(427 words)
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| | Run-length Encoding |
| | This encoding method is frequently applied to images (or pixels in a scan line). | | | In the worst case (Random Noise) encoding is more heavy than original file: 2*integer rather 1* integer if data is represented as integers. | | | the length of the ith run of pixels (Not dissimilar to zero length supression above). |
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http://www.cs.cf.ac.uk/Dave/Multimedia/node205.html
(64 words)
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| | R: Run Length Encoding |
| | Compute the lengths and values of runs of equal values in a vector. | | | x <- rev(rep(6:10, 1:5)) rle(x) ## $lengths ## [1] 5 4 3 2 1 ## $values ## [1] 10 9 8 7 6 | | | a vector containing the length of each run. |
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http://www.nku.edu/~longa/Rweb/library/base/html/rle.html
(44 words)
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| | Run-Length Encoding |
| | In run-length encoding, repetitive source such as a string of numbers can be represented in a compressed form, for example, | | | In this case, RLE yields a compression ratio of 2:1. | | | Thus, giving a compression ratio of = 9/4 : 1 which is almost 2 : 1. |
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http://www.eee.bham.ac.uk/WoolleySI/All7/run_2.htm
(80 words)
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| | run-length encoding - Glossary - CNET.com |
| | Bitmapped graphics files are typically larger than they need to be. | | | Run-length encoding is a compression technique that reduces file sizes, especially for black-and-white or cartoon-style line art graphics. | | | The more runs there are, and the longer the run sequence, the greater the compression. |
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http://www.cnet.com/Resources/Info/Glossary/Terms/runlengthencoding.html
(57 words)
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| | Re: remote protocol run length encoding |
| | "J.T. Conklin" wrote: > The problem is in the way the run length is encoded. | | | > The run length encoding used by Cisco's remote protocol varient is > safe, as it uses two hex digits to represent the length. | | | This is sounding like the existing rle method should be deprecated. |
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http://www.cygwin.com/ml/gdb/1999-q3/msg00287.html
(183 words)
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| | [No title] |
| | Text files use multiple spaces to separate, indent paragraphs, format tables & charts, e.t.c In generalized run-length encoding scheme pack bits are used If we restrict input to characters from 0-127. | | | It is common when file represents a signal. ¡ ó ¨ ¡ ( ¨ If the original signal is a not changing or is changing in a straight line then we can use run length encoding after the delta encoding. | | | first 7 bits are used to indicate character 8 bit is used to indicate if run-length encoding is in progress. |
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http://www.cps.cmich.edu/lee1ry/public_html/2004/610/Data_Compression.ppt
(467 words)
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| | Run-Length Encoding |
| | For binary files we can be even more concise: | | | Run-length encoding isn't much good for text files, as repeated sequences aren't that common. | | | Many standard image-file formats are essentially compressed versions of the simple bitmap representation - run-length encoding is one compression method used. |
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http://www.cee.hw.ac.uk/~alison/ds98/node97.html
(124 words)
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| | Xtreme Visual Basic Talk - Run Length Encoding (RLE) |
| | The hard bit for me at the mo would be the reading of the binary files into this format | | | I wanna write my own image compression algorithm. | | | Well I found a quick tutorial on the theory of RLE and it looks like quite a simple idea, I was just wondering on how I would implement it. |
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http://www.visualbasicforum.com/showthread.php?t=9432
(298 words)
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| | Definition: run-length encoding |
| | run-length encoding: A redundancy-reduction technique for facsimile in which a run of consecutive picture elements having the same state (gray scale or color) is encoded into a single code word. |
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http://www.atis.org/tg2k/_run-length_encoding.html
(47 words)
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| | Re: run length encoding - K Listbox Archive - Kx Systems |
| | instead of encoding singletons with negative octals: a:"aaabcddddd" rle:{ i:and~0=':x j:-':i,#x,//+("\\",/:$j;x i)} `0:rle a \3a\1b\1c\5d 2. | | | > > > the encoding is a list of repeating (length;value) > and non-repeating (-length;values) chunks. | | | Re: run length encoding - K Listbox Archive - Kx Systems |
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http://www.kx.com/listbox/k/msg02590.html
(214 words)
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| | High-Tech Dictionary Definition |
| | (RLE).A data compression technique that substitutes a single character and a number for a run of identical characters; for example 17* would represent a run of 17 asterisks. |
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http://www.computeruser.com/resources/dictionary/definition.html?lookup=4417
(28 words)
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| | Network Publishing - Run-length Encoding |
| | It can be compressed by a method called run-length encoding which records the sequences of 0's and 1's: | | | Consider the following bitmap "picture" of a letter K: This contains 20 x 15 = 300 pixels. |
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http://web.cs.wpi.edu/~kal/elecdoc/swati/MMrle.html
(52 words)
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| | Description of loadobj |
| | loadobj function - undoes run length encoding if appropriate | | | 0001 function o = loadobj(o) 0002 % loadobj function - undoes run length encoding if appropriate 0003 % 0004 % $Id: loadobj.m,v 1.1.1.1 2003/06/28 23:53:23 matthewbrett Exp $ 0005 0006 m = o.dat; 0007 if isfield(m, 'rlem') 0008 dat = my_rld(m.rlem); 0009 o.dat = reshape(dat, m.dim); 0010 end | | | loadobj function - undoes run length encoding if appropriate $Id: loadobj.m,v 1.1.1.1 2003/06/28 23:53:23 matthewbrett Exp $ |
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http://www.umich.edu/~fmri/course/files/spm2/toolbox/marsbar/doc/marsbar/@maroi_matrix/loadobj.html
(91 words)
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