Pseudorandom number generator image
Write a program that creates an image from a Pseudorandom Number Generator (PRNG) algorithm's output. The image can have the following dimensions:
- Task
- 250px by 250px : If the algorithm requires the use of prime numbers, use 8-15 bit primes.
- 500px by 500px : If the algorithm requires the use of prime numbers, use 8-15 bit primes.
- 1000px by 1000px : If the algorithm requires the use of prime numbers, use 8-32 bit primes.
- 1500px by 1500px : If the algorithm requires the use of prime numbers, use 16-64 bit primes.
- Possible Output
https://www.random.org/analysis/randbitmap-rdo.png
- See also
Go
The math/rand package uses a custom algorithm attributed to D.P.Mitchell and J.A.Reeds. It doesn't need to be seeded by a prime number. Typically (as here) the seed is generated from the current time.
The image is saved to a .png file which can then be viewed with a utility such as EOG. <lang go>package main
import (
"image" "image/color" "image/png" "log" "math/rand" "os" "time"
)
func main() {
rand.Seed(time.Now().UnixNano()) img := image.NewNRGBA(image.Rect(0, 0, 1000, 1000)) for x := 0; x < 1000; x++ { for y := 0; y < 1000; y++ { col := color.RGBA{uint8(rand.Intn(256)), uint8(rand.Intn(256)), uint8(rand.Intn(256)), 255} img.Set(x, y, col) } } fileName := "pseudorandom_number_generator.png" imgFile, err := os.Create(fileName) if err != nil { log.Fatal(err) } defer imgFile.Close()
if err := png.Encode(imgFile, img); err != nil { imgFile.Close() log.Fatal(err) }
}</lang>
Java
Following implementation generates images from java.util.Random(uses linear congruential generator [4].) and Blum Blum Shub Algorithm with least significant bit method and even bit parity method[5]. <lang Java> import javax.imageio.ImageIO; import java.awt.*; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.math.BigInteger; import java.security.SecureRandom; import java.util.Random; import java.util.Scanner; /*
- Numbers to try:
- p = 11 or BigInteger.probablePrime(BIT1_LENGTH, rand)
- q = 23 or BigInteger.probablePrime(BIT_LENGTH, rand)
- seed = 3 or BigInteger.probablePrime(BIT_LENGTH,rand)
- */
public class csprngBBS {
public static Scanner input = new Scanner(System.in); private static final String fileformat = "png"; private static String bitsStri = ""; private static String parityEven = ""; private static String leastSig = ""; private static String randomJavaUtil = ""; private static int width = 0; private static int BIT_LENGTH = 0; private static final Random rand = new SecureRandom(); private static BigInteger p = null; // 11 private static BigInteger q = null; // 23 private static BigInteger m = null; private static BigInteger seed = null; // 3 private static BigInteger seedFinal = null; private static final Random randMathUtil = new SecureRandom(); public static void main(String[] args) throws IOException { System.out.print("Width: "); width = input.nextInt(); System.out.print("Bit-Length: "); BIT_LENGTH = input.nextInt(); System.out.print("Generator format: "); String useGenerator = input.next(); p = BigInteger.probablePrime(BIT_LENGTH, rand); q = BigInteger.probablePrime(BIT_LENGTH, rand); m = p.multiply(q); seed = BigInteger.probablePrime(BIT_LENGTH,rand); seedFinal = seed.add(BigInteger.ZERO); if(useGenerator.contains("parity") && useGenerator.contains("significant")) { findLeastSignificant(); findBitParityEven(); createImage(parityEven, "parityEven"); createImage(leastSig, "significant"); }
if(useGenerator.contains("parity") && !useGenerator.contains("significant")){ findBitParityEven(); }
if(useGenerator.contains("significant") && !useGenerator.contains("parity")){ findLeastSignificant(); createImage(leastSig, "significant"); }
if(useGenerator.contains("util")){ findRandomJava(randMathUtil); createImage(randomJavaUtil, "randomUtilJava"); } } public static void findRandomJava(Random random){ for(int x = 1; x <= Math.pow(width, 2); x++){ randomJavaUtil += random.nextInt(2); } }
public static void findBitParityEven(){ for(int x = 1; x <= Math.pow(width, 2); x++) { seed = seed.pow(2).mod(m); bitsStri = convertBinary(seed); char[] bits = bitsStri.toCharArray(); int counter = 0; for (char bit : bits) { if (bit == '1') { counter++; } } if (counter % 2 != 0) { parityEven += "1"; } else { parityEven += "0"; } } }
public static void findLeastSignificant(){ seed = seedFinal; for(int x = 1; x <= Math.pow(width, 2); x++){ seed = seed.pow(2).mod(m); leastSig += bitsStri.substring(bitsStri.length() - 1); } }
public static String convertBinary(BigInteger value){ StringBuilder total = new StringBuilder(); BigInteger two = BigInteger.TWO; while(value.compareTo(BigInteger.ZERO) > 0){ total.append(value.mod(two)); value = value.divide(two); } return total.reverse().toString(); }
public static void createImage(String useThis, String fileName) throws IOException { int length = csprngBBS.width; // Constructs a BufferedImage of one of the predefined image types. BufferedImage bufferedImage = new BufferedImage(length, length, 1/*BufferedImage.TYPE_INT_RGB*/); // Create a graphics which can be used to draw into the buffered image Graphics2D g2d = bufferedImage.createGraphics(); for (int y = 1; y <= length; y++) { for (int x = 1; x <= length; x++) { if (useThis.startsWith("1")) { useThis = useThis.substring(1); g2d.setColor(Color.BLACK); g2d.fillRect(x, y, 1, 1); } else if (useThis.startsWith("0")) { useThis = useThis.substring(1); g2d.setColor(Color.WHITE); g2d.fillRect(x, y, 1, 1); } } System.out.print(y + "\t"); } // Disposes of this graphics context and releases any system resources that it is using. g2d.dispose(); // Save as file File file = new File("REPLACEFILEPATHHERE" + fileName + "." + fileformat); ImageIO.write(bufferedImage, fileformat, file); }
} </lang>
Julia
Julia uses the Mersenne Twister algorithm for its default rand() function. That algorithm uses over 600 32-bit ints to represent its internal state, rather than just a product of two or three primes. <lang julia>using FileIO, ImageIO
save("randombw.png", rand(Float16, 1000, 1000)) </lang>
Perl
<lang perl>use strict; use warnings; use GD;
my $img = new GD::Image(500, 500, 1);
for my $y(0..500) {
for my $x(0..500) { my $color = $img->colorAllocate(rand 256, rand 256, rand 256); $img->setPixel($x, $y, $color); }
}
open F, "image500.png"; print F $img->png;</lang> image500.png (sample image, offsite)
Raku
MoarVM uses Mersenne Twister as its PRNG but a prime seeder is not mandatory. <lang perl6># 20200818 Raku programming solution
use Image::PNG::Portable;
srand 2⁶³ - 25; # greatest prime smaller than 2⁶³ and the max my system can take
my @data = < 250 500 1000 1500 >;
@data.map: {
my $o = Image::PNG::Portable.new: :width($_), :height($_); for ^$_ X ^$_ -> @pixel { # about 40% slower if split to ($x,$y) or (\x,\y) $o.set: @pixel[0], @pixel[1], 256.rand.Int, 256.rand.Int, 256.rand.Int } $o.write: "image$_.png" or die;
}</lang>
- Output:
file image*.png image1000.png: PNG image data, 1000 x 1000, 8-bit/color RGBA, non-interlaced image1500.png: PNG image data, 1500 x 1500, 8-bit/color RGBA, non-interlaced image250.png: PNG image data, 250 x 250, 8-bit/color RGBA, non-interlaced image500.png: PNG image data, 500 x 500, 8-bit/color RGBA, non-interlaced
image500.png (sample image, offsite)
Wren
Wren's 'random' module uses the 'Well equidistributed long-period linear' (WELL512a) PRNG which doesn't need to be seeded with a prime number. It is in fact seeded from a sequence of 16 numbers but, if less are provided, the others are generated automatically. Typically (as here) the seed is generated from the current time. <lang ecmascript>import "dome" for Window import "graphics" for Canvas, Color import "random" for Random
class Game {
static init() { Window.title = "Pseudorandom Number Generator Image" Window.resize(1000, 1000) Canvas.resize(1000, 1000) var r = Random.new() // generates seed from current time for (x in 0...1000) { for (y in 0...1000) { var c = Color.rgb(r.int(256), r.int(256), r.int(256)) Canvas.pset(x, y, c) } } }
static update() {}
static draw(dt) {}
}</lang>