SUMMARY / RELATED TOPICS

Run-length encoding

Run-length encoding is a form of lossless data compression in which runs of data are stored as a single data value and count, rather than as the original run. This is most useful on data. Consider, for example, simple graphic images such as icons, line drawings, Conway’s Game of Life, animations, it is not useful with files that don't have many runs as it could increase the file size. RLE may be used to refer to an early graphics file format supported by CompuServe for compressing black and white images, but was supplanted by their Graphics Interchange Format. RLE refers to a little-used image format in Windows 3.x, with the extension rle, a Run Length Encoded Bitmap, used to compress the Windows 3.x startup screen. For example, consider a screen containing plain black text on a solid white background. There will be many long runs of white pixels in the blank space, many short runs of black pixels within the text. A hypothetical scan line, with B representing a black pixel and W representing white, might read as follows: WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW With a run-length encoding data compression algorithm applied to the above hypothetical scan line, it can be rendered as follows: 12W1B12W3B24W1B14W This can be interpreted as a sequence of twelve Ws, one B, twelve Ws, three Bs, etc.

The run-length code represents the original 67 characters in only 18. While the actual format used for the storage of images is binary rather than ASCII characters like this, the principle remains the same. Binary data files can be compressed with this method. However, newer compression methods such as DEFLATE use LZ77-based algorithms, a generalization of run-length encoding that can take advantage of runs of strings of characters. Run-length encoding can be expressed in multiple ways to accommodate data properties as well as additional compression algorithms. For instance, one popular method encodes run lengths for runs of two or more characters only, using an "escape" symbol to identify runs, or using the character itself as the escape, so that any time a character appears twice it denotes a run. On the previous example, this would give the following: WW12BWW12BB3WW24BWW14This would be interpreted as a run of twelve Ws, a B, a run of twelve Ws, a run of three Bs, etc. In data where runs are less frequent, this can improve the compression rate.

One other matter is the application of additional compression algorithms. With the runs extracted, the frequencies of different characters may be large, allowing for further compression. To overcome this, some run-length encoders separate the data and escape symbols from the run lengths, so that the two can be handled independently. For the example data, this would result in the string "WWBWWBBWWBWW" and the numbers. Run-length encoding schemes were employed in the transmission of analog television signals as far back as 1967. In 1983, run-length encoding was patented by Hitachi. RLE is well suited to palette-based bitmap images such as computer icons, was a popular image compression method on early online services such as CompuServe before the advent of more sophisticated formats such as GIF, it does not work well on continuous-tone images such as photographs, although JPEG uses it on the coefficients that remain after transforming and quantizing image blocks. Common formats for run-length encoded data include Truevision TGA, PackBits, PCX and ILBM.

The International Telecommunication Union describes a standard to encode run-length-colour for fax machines, known as T.45. The standard, combined with other techniques into Modified Huffman coding, is efficient because most faxed documents are white space, with occasional interruptions of black. Kolakoski sequence Look-and-say sequence Comparison of graphics file formats Golomb coding Burrows–Wheeler transform Recursive indexing Run-length limited Bitmap index Forsyth–Edwards Notation, which uses run-length-encoding for empty spaces in chess positions. DEFLATE Run-length encoding implemented in different programming languages

Karnak Café

Karnak Café is a novella written in 1974 by Egyptian writer Naguib Mahfouz, winner of the Nobel Prize in Literature in 1988. The novel was made into a film of the same name in 1975. Set against the discussions between the patrons of a café in Cairo, the Karnak Café, the book follows the stories of three individuals during the 1960s, including the Six-Day War and the War of Attrition, it therein explores some of the political currents vying for control over Egyptian politics in the 1960s as well as political persecution, the deep state, state violence. The narrator begins the story by describing how he discovered the Karnak Café in Cairo, attracted by the quiet charms of Qurunfula, a bellydancer of former fame and the café's owner. There, the narrator becomes part of the café's regular crowd of patrons, which represent a cross-section of Egyptian society during the early 1960s. Among many others, the crowd includes the following young people: Hilmi Hamada, an idealistic communist with whom Qurunfula has a discreet love affair.

Throughout the story, the youth are arrested and imprisoned for prolonged periods. After their third prison term, the café learns that Hilmi Hamada has died in prison, leaving Qurunfula distraught; as Isma'il and Zaynab open up to the narrator, he learns of the horrors Isma'il and Zaynab endured in prison – Isma'il is tortured while Zaynab is raped – and how the ruthless and brutal police officer Khalid Sawfan turned both Isma'il and Zaynab into informants for the secret police after their second term in prison. As Hilmi tries to convince Isma'il and Zaynab of the necessity of communism, he is betrayed by Zaynab, who tries to thereby keep Isma'il safe, is beaten to death in prison; the defeat of the Egyptian army during the Six-Day War sees Isma'il, imprisoned in spite of Zaynab's assistance, a reversal of fortunes: after being thrown into prison and having become disabled through torture, Sawfan joins the regular crowd of the Karnak Café, painting himself both as a criminal and a victim and gaining the patrons' appreciation through witty political commentary.

The novel ends on a hopeful note with Qurunfula setting her eyes upon Munir Ahmad, a new idealistic and innocent youth: for purity and innocence never disappear forever. Karnak Café on the website of the American University of Cairo Press

WOW Christmas: Red

WOW Christmas: Red is the first release in the WOW Christmas series. The double CD contains 31 Christmas songs performed by top Contemporary Christian Music artists, it peaked at 45 on the Billboard 200 and in first place on Billboard's Top Contemporary Christian album chart in the year 2002. The album was certified platinum in 2006 by the Recording Industry Association of America. Avalon - Winter Wonderland – 2:41 Michael W. Smith - Emmanuel – 5:26 Point of Grace - O Holy Night – 5:30 Steven Curtis Chapman - Christmas Is All In The Heart – 5:16 Yolanda Adams - Have Yourself A Merry Little Christmas – 3:35 Jaci Velasquez - Let It Snow, Let It Snow, Let It Snow – 2:36 CeCe Winans - Away In A Manger – 4:24 Soulful Celebration - Hallelujah! – 5:53 4Him - A Strange Way To Save The World – 4:32 Amy Grant - Breath Of Heaven – 5:30 Nicole C. Mullen - O Come, O Come Emmanuel – 4:17 Mark Schultz and Nichole Nordeman - Silent Night – 3:18 Kirk Franklin - The Night That Christ Was Born – 4:33 Kathy Mattea - Mary, Did You Know?

– 3:14 Donnie McClurkin - Hark! The Herald Angels Sing – 5:23 Rachael Lampa - Ave Maria – 4:54 Third Day - Do You Hear What I Hear? – 3:58 Jennifer Knapp - Sing Mary Sing – 4:05 ZOEgirl - Angels We Have Heard On High – 3:46 MercyMe - What Child Is This? – 3:49 tobyMac - This Christmas – 3:15 Sixpence None the Richer - Christmastime Is Here – 3:03 Jars of Clay - God Rest Ye Merry Gentlemen – 3:03 Caedmon's Call - It Came Upon A Midnight Clear – 2:48 Plus One - A Prayer For Every Year – 4:21 Rebecca St. James - Sweet Little Jesus Boy – 3:35 FFH - The First Noel – 4:48 Out of Eden - O Little Town Of Bethlehem – 3:34 Fred Hammond - Go Tell It On The Mountain – 3:52 Stacie Orrico - O Come All Ye Faithful – 3:58 Audio Adrenaline - Little Drummer Boy – 3:07 Review at Amazon.com. Retrieved 21 March 2007