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1
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2answers
140 views

How does Yahoo's Smush.It work and why doesn't everyone use it?

I've recently come across an application by Yahoo called SmushIt. Apparently it does lossless compression on images. Sometimes the image size is reduced by as much as 90%. This of course has major ...
0
votes
3answers
161 views

How would you go about compressing a list of integers that are non unique and retain the original order?

Let's start out with an example [1,1,1,5,3,1,1,2,78,2,3,1,1,...,1] As you can tell by the example, 1 is repeated a lot, but there will be outliers (like 78, and really anything that isn't 1). The ...
1
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2answers
82 views

Is hash calculated before/after compression?

I had a question regarding compression and calculation of checksum/hash of data. I would like to know if checksum has to be calculated before or after the compression of data before transmission. ...
-1
votes
2answers
181 views

Estimation of space is required to store 275305224 of 5x5 MagicSquares? [closed]

Here are some examples of 5x5 Magic Squares found by some good solvers : Magic Square Generator by Marcel Roos this program state using 2.4GHz Intel takes about 95 hours to generate all solutions. ...
2
votes
1answer
250 views

JavaScript Compression and Caching of Assets

I'm working on an idea that i can't seem to find a good answer though hours and hours of searching, I'm planning a small Canvas/WebGL Application this application will be using WebSockets to talk to ...
-1
votes
1answer
148 views

If we could get a file's binary form, would this method of file compression work?

I'm not quite sure how easy it is to fetch the binary composition of a file, but suppose we have some file with this representation: 010011 We could make 2 arrays. One which stores the position of ...
0
votes
0answers
39 views

Efficiently storing and parsing client's browser details

Do there exist browser fingerprinting API's that instead of running browser information (e.g. the user agent, installed plugins, screen resolution, system fonts etc.) through a hash function, instead ...
1
vote
2answers
802 views

How do I find average bits per symbol using huffman code?

I'm trying to write a program in c for Huffman coding, but I am stuck. For input I have: Sample input: 4 // here I scan how many letters I have A 00 // and for everyone I scan how they are ...
2
votes
1answer
298 views

What is (or where can i find) the algorithm to decode FLAC to PCM?

I'm trying to program a very basic FLAC player using 100% C# completely from scratch. My understanding of this type of thing is very limited, so I'm using this project as a way to learn about ...
1
vote
1answer
301 views

How to choose parameter for Golomb coding?

I am trying to implement Golomb coding, but I don't understand how it's tuned to obtain optimal code. It is said that Golomb coding uses a tunable parameter M to divide an input value into two ...
2
votes
4answers
483 views

What data cannot be compressed by huffman codes?

What kind of data cannot be compressed by using the huffman codes and why? I tried looking for the answer, but I only came across loss-less and lossy compression. I don't really understand what ...
0
votes
1answer
126 views

Algorithm for compression of a dictionary (words and definitions)

The theoretical situation is this: Let's say that we have a digital dictionary (by which I mean a traditional list of words and definitions, not an associative array). For the sake of simplicity, ...
-1
votes
1answer
140 views

Take dynamic PHP array, package up as separate files inside a single zip file

I have this dynamic data in PHP, but for each array record, I want to allow a downloadable option to save a zip archive of all records (each as a separate file). These are actually DNS zone records ...
3
votes
4answers
4k views

Fast compression in C++ and decompression in C#

Overview I am working on a client-server application. The client is written in C++ (working on Windows, planning to support Linux) and the server is a .NET RESTful service. I need to HTTP POST some ...
3
votes
2answers
259 views

Arithmetic Coding vs. Machine Numeric Precision

When subdividing intervals for arithmetic coding, the worst case scenario is that the final interval will have size 2^(1-n), where n is the number of unique symbols you are encoding. This will reach ...
2
votes
2answers
362 views

Arithmetic Coding Questions

I have been reading up on arithmetic coding and, while I understand how it works, all the guides and instructions I've read start with something like: Set up your intervals based upon the ...
4
votes
1answer
287 views

What should developers know about Windows executable binary file compression?

I'd never heard of this before, so shame on me, but programs like UPX can compress my files by 80% which is totally sweet, but I have no idea what the the disadvantages are in doing this. Or even ...
1
vote
1answer
135 views

Is it possible to modify a video codec + distribute it?

this is my first question on this particular stackexchange node, not sure if it's the most appropriate place for this question (if not, guidance to the appropriate node would be appreciated). the ...
3
votes
2answers
183 views

Where can I find good example of techniques to compact data in-memory? [closed]

I'm writing a Java framework to manipulate a large amount of data in-memory, where many "cells" that are near each other will have the same value. I'm looking for algorithms and/or techniques ...
5
votes
4answers
1k views

How effective are CSS, Javascript and HTML compression tools and is it worth to compress files?

I looked into minified versions of jQuery and also various online CSS & HTML compression tools. I tried compressing few CSS files and gained only 20-30% compression. Are these compression tools ...
0
votes
3answers
109 views

Should I decompress zips before I archive?

I am writing a small personal archiving tool. I frequently work with a lot of client databases for short periods, what my tool will do is in overnight batch jobs it will detach the database and zip up ...
0
votes
1answer
375 views

What's the best way to deal with large compressed files over FTP?

In my application, I'm getting product information files from an FTP server. They are text files that have been ZIP-compressed. At first, I thought uncompressed the file on the server then reading ...
0
votes
4answers
500 views

What web oriented language would work best with binary data? [closed]

I want to create a service where people can upload files. However, since file storage costs money, I want to compress the files so they take less space. I would want to write my own compression ...
4
votes
4answers
412 views

Randomly Accessing Data Packets in a Compressed File

In my line of work I deal with very large files, hundreds of Gigabytes in size. The nature of the data in these files is such that compression would greatly reduce their size. The problem is, the ...