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Aliased.png (128 × 128 pixels, file size: 781 bytes, MIME type: image/png)

Summary

Description
English: Aliased chessboard
Date 24 January 2003 (original upload date)
Source Created with a variant of this program, which I (Loisel 03:56 Jan 24, 2003 (UTC)) wrote myself.
Author Loisel at English Wikipedia

Licensing

Loisel at the English Wikipedia, the copyright holder of this work, hereby publishes it under the following license:
GNU head Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.
w:en:Creative Commons
attribution share alike
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
Attribution: Loisel at the English Wikipedia
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
This licensing tag was added to this file as part of the GFDL licensing update.


C src code

Original code:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <assert.h>
int color(double x, double y)
{
  double t,z;
  int i,j,k;

  x=x/128.0-0.5;
  y=y/2048.0;

  t=1.0/(y+0.001);
  z=t*x;
  i=floor(t);
  j=floor(z);
  k=i+j;
  /*  printf("%f %f -> %i %i %i\n",t,z,i,j,k%2); */
  return ((k%2)!=0);
}

double myrand()
{
  return rand()/((double)RAND_MAX);
}

int main()
{
  int i,j,k,l;
  double x,y;
  printf("P5\n128 128\n255\n");
  srand(time(0));
  for(i=0;i<128;i++)
    for(j=0;j<128;j++)
      {
 k=0;
 for(l=0;l<255;l++)
   {
     x=j+myrand();
     y=i+myrand();
     k+=color(x,y);
   }
 assert(k>=0 && k<=255);
 putchar(k);
      }
}

New code with only small changes :

To compile :

 gcc a.c -Wall -lm

to run :

./a.out >a.pgm

To convert using Image Magic :

convert 5000.pgm -resize 1000x1000 a.png


// https://commons.wikimedia.org/wiki/File:Aliased.png
// gcc a.c -Wall -lm
//  gcc a.c -Wall -lm
// ./a.out >a.pgm


#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <assert.h>



int iMax =5000;
int jMax ; 



int color(double x, double y)
{
  double t,z;
  int i,j,k;

  
  x=x/(1.0*iMax)-0.5;
  y=y/(jMax*6);
 
  t=1.0/(y+0.001);
  z=t*x;
  i=floor(t);
  j=floor(z);
  k=i+j;
  /*  printf("%f %f -> %i %i %i\n",t,z,i,j,k%2); */
  return ((k%2)!=0);
}
 
double myrand()
{
  return rand()/((double)RAND_MAX);
}
 
int main()
{
  int i,j,k,l;
  double x,y;
 
  jMax = iMax;


  printf("P5\n %d %d\n255\n", iMax, jMax);
  srand(time(0));
  

  for(i=0;i<iMax;i++)
    for(j=0;j<jMax;j++)
      {
        k=0;
        for(l=0;l<255;l++)
	  {
	    x=j+myrand();
	    y=i+myrand();
	    k+=color(x,y);
	  }
        assert(k>=0 && k<=255);
        putchar(k);
      }

  return 0;

}

Source code was formatted with Emacs using GNU style.

Original upload log

The original description page was here. All following user names refer to en.wikipedia.
  • 2007-09-15 05:17 Dicklyon 128×128×8 (892 bytes) Reverted to version as of 13:34, 30 September 2005
  • 2007-09-14 22:56 AzaToth 1600×1200×8 (42986 bytes) remade it in povray
  • 2005-09-30 13:34 Riumplus 128×128×8 (892 bytes) Losslessly recompressed the image, shrinking file size by 39%
  • 2003-01-24 20:28 Loisel 128×128×8 (1450 bytes) slightly bugfixed image

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

24 January 2003

image/png

bfbecdb8c35d141320686b9adfd6f560e87eaa30

781 byte

128 pixel

128 pixel

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current09:49, 17 May 2023Thumbnail for version as of 09:49, 17 May 2023128 × 128 (781 bytes)PhreneticcReduced file weight with FileOptimizer in lossless compression mode.
16:06, 27 July 2014Thumbnail for version as of 16:06, 27 July 2014128 × 128 (892 bytes)OgreBot(BOT): Reverting to most recent version before archival
16:06, 27 July 2014Thumbnail for version as of 16:06, 27 July 20141,600 × 1,200 (42 KB)OgreBot(BOT): Uploading old version of file from en.wikipedia; originally uploaded on 2007-09-14 22:56:12 by AzaToth
16:06, 27 July 2014Thumbnail for version as of 16:06, 27 July 2014128 × 128 (1 KB)OgreBot(BOT): Uploading old version of file from en.wikipedia; originally uploaded on 2003-01-24 20:28:17 by Loisel
06:19, 27 July 2014Thumbnail for version as of 06:19, 27 July 2014128 × 128 (892 bytes)LocalHreverted to previous version, was aliased for descriptive purposes
18:14, 27 June 2014Thumbnail for version as of 18:14, 27 June 20141,000 × 1,000 (154 KB)Soul windsurferbetter quality
19:43, 3 May 2007Thumbnail for version as of 19:43, 3 May 2007128 × 128 (892 bytes)MrHyde~commonswiki{{Information |Description= |Source= |Date= |Author= |Permission= |other_versions= }}

Global file usage

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