Compression of large arrays of primes

Compression of large arrays of primes
 
The properties of prime numbers rarely allow them to work differently than in the form of a pre-computed array - and preferably as large as possible. The natural format of storage in the form of integers of this or that digitization suffers with some disadvantages, which become significant with the growth of the data volume.
 
Thus, the format of 16-bit unsigned integers with the size of such a table of about 13 kilobytes contains only 6542 prime numbers: after the number of 65531 there are values ​​of higher bit depth. Such a table is suitable only as a toy.
 
The most common 32-bit integer format in programming ...
+ 0 -

Codec 2 + neural network = a whole podcast on one floppy disk

In the previous article we talked about the Opus codec, which works at very low bitrates. But another codec is trying to achieve even lower bitrates - it's Codec 2 .
 
 
Codec 2 is intended for encoding only speech. And although the bitrate is impressive, the sound is not as good as in the case of Opus, which can be heard in audio examples . However, in combination with the neural network ( WaveNet ), The codec demonstrates impressive results .
 
 
Codec 2 + neural network = a whole podcast on one floppy disk ...
+ 0 -

As we added the entrances to the map and reduced the size of the bases by 10%

As we added the entrances to the map and reduced the size of the bases by 10%  
 
At the end of last month 2GIS began to display entrances. Entrances to the organization we show already as early as 201? and entrances - it seems like the same entrances. So why just now? All internal products and processes are ready, just something you need to refine a little more and correct the mapping in the UI.
 
 
In addition to the standard answer "There were other priorities," there is not quite a standard one: "It's not so simple." This article is about what were the difficulties and how we solved them.
 
...
+ 0 -

Walk between pixels

Walk between pixelsThis post refers to my article on the calculation of points on Bezier curves using linear interpolation of textures. The extended method extends to Bezier surfaces and (multidimensional) polynomials.
 
 
The initial observation was that if you sampled the 2 × 2 texture diagonally, then the output points are points on the quadratic Bezier curve, and the reference points of the curve are the pixel values, as in the image below. When I say that you are getting a quadratic curve Bezier, then I express myself literally and accurately. This can be represented as follows: the interpolation of the ...
+ 0 -

Literary archiver

Literary archiverFirst of all, I congratulate all Orthodox and their sympathizers with Easter and the end of the great post, all the rest - with the onset of spring. In the sandbox, just a month ago, at last, my debut about programming in Cyrillic was drowned. I do not know what attracted the attention of readers to greenery, but commented on the sheets, like a real article. In his bed sheet TrllServ I suggested using the idea for archiving. I adore people who know how to find practical applications for ideas. Having unfolded the notepad, I tried to outline the algorithm based on the property of my encoding...
+ 0 -

Strong data encryption in PNG

 
Good morning, Habr. I read yesterday article about hash-steganography through social networks, and I came up with the idea to do something more optimal in terms of the amount of output. It turned out something more or less workable and even optimized (as opposed to 3r3r3? proof-of-concept
? romabibi
), Therefore, like promised , writing an article.
 
 
Well, I'll say hello to you again: Strong data encryption in PNG , and welcome to the cat.
 
 
I decided to implement the idea as much as possible in a stupid way simply...
+ 0 -

Batch processing of images in Windows with ImageMagick. Part I

ImageMagick - A free and cross-platform editor for working with graphics.
 
It consists of several console utilities. His capabilities can not be counted as stars in the sky.
 
There are a lot of in the network. examples , how to use it. But most of them are for Linux or PHP. For Windows, their cat cried. It's time to fill the gap.
 
Q16 .
 
 
During installation, check the checkboxes:
 
 
Batch processing of images in Windows with ImageMagick. Part I
 
 
Thus, we get the whole set of utilities and add them to the system variable path.
 
 
[h2] Batch compression ...[/h]
+ 0 -