compression

I have a sequence of n integers in a small range [0,k) and all the integers have the same frequency f (so the size of the sequence is n=f∗k ). What I'm trying to do now is to compress this sequence while providing random access (what is the i-th integer). The time to achieve random access doesn't have to be O(1). I'm more interested in achieving high compression at the expense of higher random access times. I haven't tried with Huffman coding since it assigns codes based on frequencies (and all my frequencies are the same). Perhaps I'm missing some simple encoding for this particular case. Any

I've got a javascript application that sends a large amount of numerical data down the wire. This data is then stored in a database. I am having size issues (too much bandwidth, database getting too big). I am now ready to sacrifice some performance for compression. I was thinking of implementing a base 62 number.toString(62) and parseInt(compressed, 62). This would certainly reduce the size of the data but before I go ahead and do this I thought I would put it to the folks here as I know there must be some outside the box solution I have not considered. The basic specs are: - Compress large

Which compression method is better? I've heard lots of back and forth about GZip being more widely used, but Deflate being faster (in some instances). Is there an accepted standard on which one to use and why? eigenein UPDATE According to the latest updates to the linked question, one should use GZip. See http://www.vervestudios.co/projects/compression-tests/results Old Answer Deflate is better . yorah Answers: http://www.stardeveloper.com/articles/display.html?article=2008111201&page=1 http://blog.usweb.com/archives/mod_deflate-vs-mod_gzip-comparing-the-two/ Why use deflate instead of gzip

I try to create a zip file in memory with c#, but the result is a zip file with corrupted files inside it. All file to zip are in a database. I store the bytes. The files are PDF. my code is the following //[extract bytes and file name for every file] using (var zipArchiveMemoryStream = new MemoryStream()) { using (var zipArchive = new ZipArchive(zipArchiveMemoryStream, ZipArchiveMode.Create, true)) { foreach (var file in fileData) { var zipEntry = zipArchive.CreateEntry(file.FileName); using (var entryStream = zipEntry.Open()) { using (var tmpMemory = new MemoryStream(file.Bytes)) { tmpMemory

The current project in Systems Programming is to come up with an ASCII compressor that removes the top zero bit and writes the contents to the file. In order to facilitate decompression, the original file size is written to file, then the compressed char bytes. There are two files to run tests on- one that is 63 bytes long, and the other is 5344213 bytes. My code below works as expected for the first test file, as it writes 56 bytes of compressed text plus 4 bytes of file header. However, when I try it on the long test file, the compressed version is 3 bytes shorter than the original, when it

Does anyone of you know a lossless compression algorithm, which produces headerless outputs? For example do not store the huffman tree used to compress it? I do not speak about hard coded huffman trees, but I like to know if there is any algorithm that can compress and decompress input without storing some metadata in its output. Or is this even theoretically impossible? Adaptive Huffman coding does exactly that. More generally, the term adaptive coding is used to describe entropy codes with this property. Some dictionary codes have this property too, e.g. run-length encoding (RLE) and Lempel

How is it possible that in a 64kb compiled exe, these programs can generate such crazy visuals, complete with matching music? An example: Ars Nova By Phantom Lord ( YouTube video of the demo running ) This program's only 64kb in size! How did they do that? Are they using some sorts of pre-existing objects, shaders, etc. inside DirectX or something like that? What languages do they even use? Is there some sort of guide to this stuff? EDIT: Another mind-blowing demo. How? http://www.scene.org/file.php?file=/demos/groups/farb-rausch/fr08_final.zip&fileinfo EDIT: More demoscene stuff. I found some