Fractals/kallesfraktaler

From Wikibooks, open books for an open world
Jump to navigation Jump to search

Kalles Fractales

Images[edit | edit source]

See commons category: Created with Kalles Fraktaler

install[edit | edit source]

run[edit | edit source]

Launch

wine ./kf.x86_64.exe 



Set the image size the same as window size ( in View)


complex[edit | edit source]

Steps to make video

 mkdir ~/work
cd ~/work
wine32 ~/windows/fraktal_sft.exe
# render zoom out sequence with kalles fraktaler, saving to ~/work
for i in *.kfb ; do ~/code/maximus_kf-extras/pseudo-de < ${i} | pgmtoppm white > ${i%kfb}ppm done
# count number of kfb files, (ls *.kfb | tail -n 1) gives a hint, I had 311
ls *.kfb | ~/code/maximus_kf-extras/expmap 311 > expmap.pgm
ghc -e "100 / sqrt ( 565 * 19820 / (120 * 8000) )"
# or your favourite calculator program if you don't have ghc
# prints 29.27922435677391
# where 565 * 19820 is the size of the expmap
# 8000 is desired sample rate
# 120 is desired movie length in seconds
gimp expmap.pgm
# downscale by 29.27922435677391% (output from ghci)
# flip vertically
# make sure it's greyscale with no alpha
# save as expmap-downscaled.png
# gimp saves comments in its netpbm writers, my bad code doesn't handle it
pngtopnm < expmap-downscaled.png > expmap-downscaled.pgm
audacity
# import raw expmap-downscaled.pgm as raw unsigned 8bit PCM mono 8000Hz
# set project sample rate to 48000Hz
# select the track, mix and render
# select the track, apply filter DC Offset Removal (maybe needs a plugin)
# select the track, select amplify and apply to normalize the volume
# duplicate the track twice
# for each of the duplicates in turn, select it and apply a reverb (GVerb plugin)
# use slightly different reverb settings for each track (for stereo effect)
# normalize the duplicates by select track, select amplify, apply
# make one duplicate a left channel and the other a right channel
# set the levels of each track to -3dB
# select all tracks, mix and render
# normalize volume if needed
# select track, export as stereo wav 16bit PCM to expmap.wav
# note down the length (my test gave 1m56s)
ghc -e "1 * 60 + 56"
# to get the audio length in seconds (116)
# check the size of the kfb files (here I used 640 by 360)
# remember we have 311 kfb files
ls 00*.ppm | tac | xargs cat | ~/code/maximus_book/code/zoom 640 360 311 116 |
  avconv -f yuv4mpegpipe -i - -i expmap.wav -acodec vorbis -ab 192k -vb 2M out.ogv
# finally!
mplayer out.ogv

doc[edit | edit source]

videos[edit | edit source]

variables[edit | edit source]

  • T: the number type, double or long double or floatexp (used when more range is needed)
  • Zr, Zi: the final escaped Z value
  • Jxa, Jxb, Jya, Jyb: the running derivative (for complex analytic formulas Jxa = Jyb and Jxb = - Jya, aka Cauchy-Riemann conditions) Jxa = Jyb = Re(dz/dc), Jya = -Jxb = Im(dz/dc)
  • s: the pixel spacing
  • TK: the rotation and skew matrix (if you don't rotate or skew then this should be the identity matrix)

status bar[edit | edit source]

  • D%pixels done with current reference
  • G%pixels guessed by neighboring interior
  • R% reference iterations vs maxiters
  • A% series approximation skipped vs maxiters

Menu[edit | edit source]

menu depends on the version of KF

File[edit | edit source]

  • File->Open is for KFR
  • File->Open Map is for KFB

Fraktal[edit | edit source]

View[edit | edit source]

Navigation[edit | edit source]

Advanced[edit | edit source]

?[edit | edit source]

Parameters[edit | edit source]

  • seed value:
    • for the fractal type = Z0
  • Fractal type



Dialog box Iterations:

  • "Maximum number of iterations";
  • "Minimum number of iteration in current view";
  • "Maximum number of iteration in current view";
  • "Iterations skipped by Series Approximation";
  • "Bailout value for iterations";
  • "Power of Mandelbrot function";
  • "Maximum of extra references for glitch correction";
  • "Checked for low tolerance of Series Approximation\nComplex images may need this to be checked to be rendered correctly\nThe render time may be faster if this checkbox is not checked";
  • "Terms for Series approximation is adjusted\nbased on the number of pixels to be rendered.";
  • "List of type of Mandelbrot based Fractals\nSome of them have additional Power options";
  • "Terms for Series approximation.\nMore terms usually yield more skipped iterations and faster rendering,\nhowever is more time consuming to be processed";
  • "Display number of calculations performed";
  • "Include real part when checking bailout.\nUncheck for variation";
  • "Include imaginary part when checking bailout.\nUncheck for variation";
  • "Real seed value (0 is standard)";
  • "Imaginary seed value (0 is standard)";


bailout value and type[edit | edit source]

p-norm with weights:[1]

  

all of { a b p R } are configurable, with a special case for p = infinity (using max)

Seed values for the fractal type[edit | edit source]

To change open dialog window using:

  • Menu/Actions/Iterations
  • Keys: Ctrl+I

Fractal type = m_nFractalType[edit | edit source]

One can change it in the Iterations menu

  • Menu/Fractal/Iterations
  • Ctrl+I

Types:

  • 0 = Mandelbrot ( standard setting)
  • 1 = Burning Ship
  • 2 = Buffalo
  • 3 = Celtic
  • 4 = Mandelbar
  • 5 = Mandelbar Celtic
  • 6 = Perpendicular Mandelbrot
  • 7 = Perpendicular Burning Ship
  • 8 = Perpendicular Celtic
  • 9 = Perpendicular Buffalo
  • 10 = Cubic Quasi Burning Ship
  • 11 = Cubic Partial BS Real
  • 12 = Cubic Partial BS Imag
  • 13 = Cubic Flying Squirrel (Buffalo Imag)
  • 14 = Cubic Quasi Perpendicular
  • 15 = 4th Burning Ship Partial Imag
  • 16 = 4th Burning Ship Partial Real
  • 17 = 4th Burning Ship Partial Real Mbar
  • 18 = 4th Celtic Burning Ship Partial Imag
  • 19 = 4th Celtic Burning Ship Partial Real
  • 20 = 4th Celtic Burning Ship Partial Real Mbar
  • 21 = 4th Buffalo Partial Imag
  • 22 = 4th Celtic Mbar
  • 23 = 4th False Quasi Perpendicular
  • 24 = 4th False Quasi Heart
  • 25 = 4th Celtic False Quasi Perpendicular 25
  • 26 = 4th Celtic False Quasi Heart 26
  • 27 = 5th Burning Ship Partial 27
  • 28 = 5th Burning Ship Partial Mbar 28
  • 29 = 5th Celtic Mbar 29
  • 30 = 5th Quasi Burning Ship (BS/Buffalo Hybrid) 30
  • 313 = 5th Quasi Perpendicular 31
  • 32 = 5th Quasi Heart 32
  • 33 = SimonBrot 4th 33
  • 34 = 4th Imag Quasi Perpendicular / Heart 34
  • 35 = 4th Real Quasi Perpendicular 35
  • 36 = 4th Real Quasi Heart 36
  • 37 = 4th Celtic Imag Quasi Perpendicular / Heart 37
  • 38 = 4th Celtic Real Quasi Perpendicular 38
  • 39 = 4th Celtic Real Quasi Heart 39
  • 40 = SimonBrot 6th 40
  • 41 = HPDZ Buffalo : Z = |Z0|^2 - |Z| + C
  • 42 = TheRedshiftRider 1: a*z^2+z^3+c"); // 42
  • 43 = TheRedshiftRider 2: a*z^2-z^3+c"); // 43
  • 44 = TheRedshiftRider 3: 2*z^2-z^3+c"); // 44
  • 45 = TheRedshiftRider 4: a*z^2+z^4+c"); // 45
  • 46 = TheRedshiftRider 5: a*z^2-z^4+c"); // 46
  • 47 = TheRedshiftRider 6: a*z^2+z^5+c"); // 47
  • 48 = TheRedshiftRider 7: a*z^2-z^5+c"); // 48
  • 49 = TheRedshiftRider 8: a*z^2+z^6+c"); // 49
  • 50 = TheRedshiftRider 9: a*z^2-z^6+c"); // 50
  • 51 = SimonBrot2 4th // 51

files[edit | edit source]

  • KF can export raw iteration data in EXR (and obsolete KFB) formats, so you can colour it with other software

exr[edit | edit source]

EXR file channels:

  • raw iteration data = normalized iteration count[2]
    • N = integer iteration count ( uint32 )
    • NF = fractional iteration count, float in range [0.0 .. 1.0)
  • T = phase = the argument of the first Z value to escape, measured in turns
  • DE = directional Distance Estimation (when derivatives have been calculated)
  • RGB = colours (half float)
  • Metadata


The channel names are strings


normalized iteration count[edit | edit source]

uint32 N integer iteration count

0xFFFFFFFF is non-escaped before header metadata field int Iterations (or string Iterations, as it can exceed the range of int)

0x00000000 is uncalculated/glitch/no-data-available.

If actual iteration values can be zero or negative, add a bias constant to each count and store it in the header metadata field int IterationsBias (or string IterationsBias, it can exceed the range of int). The bias could be negative, this might allow you to store high iteration counts without necessarily needing two channels if the actual min/max range is small enough)

For images with biased iteration counts above 0xFFFFFFFE, split into two channels:

uint32 N0 least significant 32 bits

uint32 N1 most significant 32 bits

(0xFFFFFFFF, 0xFFFFFFFF) is interpreted as non-escaped

For future supercomputers, this can be extended with N2 etc…


The continuous iteration count (when escaped) is N+NF-IterationsBias. This is stored separately to avoid losing precision at high iteration counts

phase of first escaped Z value, measured in turns

float T in [0.0 .. 1.0)

It is desirable that this aligns with NF to give 2D exterior grid cell coordinates, KF versions before 2.15 align only with Linear smoothing.

DE[edit | edit source]

directional DE (when derivatives have been calculated)

float DEX, float DEY directional distance estimate in cartesian form, normalized such that distance to a neighbouring boundary pixel sqrt(DEX^2 + DEY^2) is approximately 1.0.

If some pixels have no directional DE the missing data can be written as (0.0, 0.0), but readers should also handle NaNs in this case. The vector points away from the fractal boundary.

jpg[edit | edit source]

JPEG is lossy

kfc[edit | edit source]

"KFC" is bNewFormat 1, vertical lines of float32 combined data (int32 iteration + float32 smooth)

kfb[edit | edit source]

Obsolete format , see exr


The map file (.kfb) contains:

  • the calculated fractal data:
    • iteration counts
      • N (max iterations , integer)
      • NF ( iteration , smooth part = double)
    • sometimes distance estimates if you enabled derivative calculations)
  • It also contains some colouring information (but this is not complete)

It does NOT contain the coordinates.

These files are created:

  • when saving the jpg files, there is also a kfb file created for each image
  • save a map

Description:

  • "KF can export raw iteration data in EXR (and obsolete KFB) formats, so you can colour it with other software"
  • "KFB files store raw uncompressed (ie huge but high quality) iteration data (the results of the fractal calculations before colouring is applied)." Claude at FF, for example raw float32 DE images (scaled to pixel spacing)
  • "the KFB files are images used as maps to store iteration data. No location, palette, etc" youhn


Claude on FF: [3]


They are strings found inside .kfb files (the first 3 bytes) to distinguish different versions of the data format stored in the file.

"KFB" is bNewFormat 0, vertical lines of int32 iteration plane followed by float32 smooth colouring plane.
"KFC" is bNewFormat 1, vertical lines of float32 combined data (int32 iteration + float32 smooth)
"KFD" is bNewFormat 2, horizontal lines of float32 combined data (int32 iteration + float32 smooth)

As far as I can tell, only "KFB" is actually saved by current versions of Kalles Fraktaler.

"KFB" is also the only format that preserves smooth colouring at high iteration counts, because single precision float32 can only represent integers after 2^24 = 16M, can only represent even integers after 2^25 = 33M, etc, with gradual degradation before that.




// from fractal_sftp.cpp  Kalles Fraktaler 2 © 2014-2015 Karl Runmo
void CFraktalSFT::SaveMapB(char *szFile)
{
	if (!m_nPixels)
		return;
	DWORD dw;
	HANDLE hFile = CreateFile(szFile, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, 0, NULL);
	int x;
	WriteFile(hFile, "KFB", 3, &dw, NULL);
	WriteFile(hFile, &m_nX, sizeof(m_nX), &dw, NULL);
	WriteFile(hFile, &m_nY, sizeof(m_nY), &dw, NULL);
	for (x = 0; x<m_nX; x++)
		WriteFile(hFile, m_nPixels[x], m_nY*sizeof(int), &dw, NULL);
	int div = m_nIterDiv;
	WriteFile(hFile, &div, sizeof(m_nParts), &dw, NULL);
	WriteFile(hFile, &m_nParts, sizeof(m_nParts), &dw, NULL);
	WriteFile(hFile, m_cKeys, sizeof(COLOR14)*m_nParts, &dw, NULL);
	WriteFile(hFile, &m_nMaxIter, sizeof(int), &dw, NULL);
	for (x = 0; x<m_nX; x++)
		WriteFile(hFile, m_nTrans[x], m_nY*sizeof(float), &dw, NULL);
	CloseHandle(hFile);
}

Here is the octave/matlab code by Gerrit:[4]

function [width,height,counts,trans,maxiter,parts,keys] = readKFB(fn)

% counts are iterations
% trans is the correction to smooth iteration count based on escape time
% (see wiki) 
% parts is number of colors, keys are the colors.
% to make a colormap(cmap):
% > cmap = reshape(keys,3,parts)'/255.;
% > cmap = flipud(fliplr(cmap));

info = dir(fn);
fid = fopen(fn,'r');
d = fread(fid, [1, info.bytes], '*uint8');
fclose(fid);
%d(1:3) == 'KFB' test skipped
k = 4;
nBytes = 4;
width = typecast(uint8(d(k:k+nBytes-1)),'uint32');
width = double(width);
k = k + nBytes;
height = typecast(uint8(d(k:k+nBytes-1)),'uint32');
height = double(height);
k = k + nBytes;
nCounts = width*height; %32 bit ints
nBytes = 4 * nCounts;
counts = typecast(uint8(d(k:k+nBytes-1)),'uint32');
counts = reshape(counts,height,width);
counts = single(counts);
k = k + nBytes;
nBytes = 4;
iterdiv = typecast(uint8(d(k:k+nBytes-1)),'uint32');
k = k + nBytes;
parts = typecast(uint8(d(k:k+nBytes-1)),'uint32');
parts = double(parts);
k = k + nBytes;
nBytes = parts * 3;
% r,g,b,... parts triples
keys = typecast(uint8(d(k:k+nBytes-1)),'uint8');
keys = double(keys);
k = k + nBytes;
nBytes = 4;
maxiter = typecast(uint8(d(k:k+nBytes-1)),'uint32');
maxiter = double(maxiter);
k = k + nBytes;
nBytes = 4 * nCounts;
trans = typecast(uint8(d(k:k+nBytes-1)),'single');
trans = reshape(trans,height,width);



File header in hexadecimal editor :

KFB....h.

kfd[edit | edit source]

kfp[edit | edit source]

kfp = Kalles Fraktaler palette files

On the file naming convention used a file name such as
"p512bcgwmryk.kfp" is a 512 colour palette a 3bit colour cube sorted into Blue, Cyan, Green, White, Magenta, Red and yellow groups, then sub sorted within these groups to get a smooth changes in colour.
Most files will have a striping ending "p512bcgwmrykof8.kfp" shifts each 2nd colour 8 places.
"p512bcgwmrykpm4816"  is a more complex striping, the 2nd colour is shifted 4 paces, the 4th 8 places, the 6th 4 places and the 8th 16 places and so on.
"p512X2bcgwyrmkof32" duplicates the 512 colour palette into light and dark halves.
"p1024bmwmbcgyrk" the "bm" stands for bit mix a more satisfactory way of sampling the 8 bit colour cube into 1024 colours.
There are a few other oddball palettes, "LenaSoderburg.kfp" is a palette that is a 32x32 low resolution version of the famous "Lena" picture use in early image processing development.

Jeremy Thomson
ColorOffset: 0
Rotate: 0
Ratio: 363.025211
Colors: 0,0,255,0,4,255,0,8,255,0,12,255,0,16,255,0,20,255,0,24,255,0,28,255,0,32,255,0,36,255,0,40,255,0,45,255,0,49,255,0,53,255,0,57,255,0,61,255,0,65,255,0,69,255,0,73,255,0,77,255,0,81,255,0,85,255,0,89,255,0,93,255,0,97,255,0,101,255,0,105,255,0,109,255,0,113,255,0,117,255,0,121,255,0,125,255,0,130,255,0,134,255,0,138,255,0,142,255,0,146,255,0,150,255,0,154,255,0,158,255,0,162,255,0,166,255,0,170,255,0,174,255,0,178,255,0,182,255,0,186,255,0,190,255,0,194,255,0,198,255,0,202,255,0,206,255,0,210,255,0,215,255,0,219,255,0,223,255,0,227,255,0,231,255,0,235,255,0,239,255,0,243,255,0,247,255,0,251,255,0,255,255,
Smooth: 0
MultiColor: 0
BlendMC: 0
MultiColors: 
Power: 2
FractalType: 0
Slopes: 0
SlopePower: 50
SlopeRatio: 50
SlopeAngle: 45
image: 1
real: 1
SeedR: 0
SeedI: 0
FactorAR: 1
FactorAI: 0


 grep -nR "kfp"
fraktal_sft/cmdline.cpp:280:"    -c, --load-palette  [FILE.kfp]  load palette file\n"
fraktal_sft/main_color.cpp:481:			if(BrowseFile(hWnd,FALSE,"Save palette","Palette\0*.kfp\0\0",szFile))
fraktal_sft/main_color.cpp:696:			if(BrowseFile(hWnd,TRUE,"Open palette","Palette\0*.kfp\0\0",szFile)){


Using

 /path/to/kf.exe -s my.kfs -l my.kfr -c my.kfp -x my.exr
 
 

For (re-)colouring existing EXR files containing raw iteration data, try

 /path/to/kf.exe -s old.exr -l old.exr -o old.exr -c new-palette.kfp  -x new.exr

kfr[edit | edit source]

  • text file
  • contain parametrs

The parameter file (.kfr) before loading the map file to be able to navigate further. You can rename .kfr to .kfp and load it in the colour dialog.


Re: -1.252075014867735555974940801848588674907763636282052371316271536003707048655691466436892204807423486911208873753204122
Im: -0.008791858755657632997049331233776536713263464347924936644487037690633902732242296004830894920786698063372255536046170 
Zoom: 2.9333318059216862E91 
Iterations: 31394 
IterDiv: 0.010000 
SmoothMethod: 0 
ColorMethod: 7 
Differences: 3 
ColorOffset: 0 
Rotate: 0.000000 
Ratio: 383.431953 
Colors: 195,192,201,41,59,47,31,230,221,54,211,5,239,241,216,219,206,62,238,205,241,9,21,23, 
InteriorColor: 0,0,0, 
Smooth: 1 
MultiColor: 0 
BlendMC: 0 
MultiColors: 
Power: 2 
FractalType: 0 
Slopes: 1 
SlopePower: 50 
SlopeRatio: 20 
SlopeAngle: 45 
imag: 1 
real: 1 
SeedR: -0.5 
SeedI: 0 
FactorAR: 1 
FactorAI: 0 
Period: 0 
ZoomSize: 2 
MaxReferences: 10000 
GlitchLowTolerance: 0 
ApproxLowTolerance: 0 
AutoApproxTerms: 1 
ApproxTerms: 63 
WindowWidth: 640 
WindowHeight: 360 
WindowTop: 318 
WindowLeft: 630 
WindowBottom: 445 
WindowRight: 660 
ImageWidth: 8000 
ImageHeight: 4500 
ThreadsPerCore: 1 
AnimateZoom: 1 
ArbitrarySize: 1 
ReuseReference: 0 
AutoSolveGlitches: 1 
Guessing: 1 
SolveGlitchNear: 0 
NoApprox: 0 
Mirror: 0 
LongDoubleAlways: 0 
FloatExpAlways: 0 
AutoIterations: 1 
ShowGlitches: 1 
NoReuseCenter: 1 
IsolatedGlitchNeighbourhood: 4 
JitterSeed: 0 
JitterShape: 0 
JitterScale: 1 
Derivatives: 0 
ShowCrossHair: 0 
UseNanoMB1: 0 
UseNanoMB2: 0 
OrderM: 16 
OrderN: 16 
InteriorChecking: 0
RadiusScale: 0.100000000000000006

Examples:

kfs[edit | edit source]

This file type is for settings (.kfs), useful for configuring command line rendering or saving presets.

png[edit | edit source]

Program can open and sve pang with comments:


/*
Kalles Fraktaler 2
Copyright (C) 2013-2017 Karl Runmo
Copyright (C) 2017-2018 Claude Heiland-Allen

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

#include <stdio.h>
#include <string.h>
#include <time.h>
#include <string>
#include <png.h>
#include <zlib.h>

#include "png.h"

static void kf_png_error_handler(png_structp png, png_const_charp msg)
{
	// FIXME make this display in the GUI or something
	fprintf(stderr, "PNG ERROR: %s\n", msg);
	longjmp(*static_cast<jmp_buf *>(png_get_error_ptr(png)), 1);
}

static void kf_png_warning_handler(png_structp png, png_const_charp msg)
{
	(void) png;
	// FIXME make this display in the GUI or something
	fprintf(stderr, "PNG WARNING: %s\n", msg);
}

static bool skip_png_image(png_structp png, png_infop info);

extern int SavePNG(const std::string &szFileName, char *Data, int nHeight, int nWidth, int nColors, const std::string &comment)
{
	jmp_buf jmpbuf;
	if (nColors != 3)
		return 0;
	FILE *file = fopen(szFileName.c_str(), "wb");
	if (! file)
		return 0;
	png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, &jmpbuf, kf_png_error_handler, kf_png_warning_handler);
	if (! png)
		return 0;
	png_infop info = png_create_info_struct(png);
	if (! info)
	{
		png_destroy_write_struct(&png, 0);
		fclose(file);
		return 0;
	}
	if (setjmp(jmpbuf))
	{
		png_destroy_write_struct(&png, &info);
		fclose(file);
		return 0;
	}
	png_init_io(png, file);
	png_set_compression_level(png, Z_BEST_COMPRESSION);
	png_set_IHDR(png, info, nWidth, nHeight, 8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_ADAM7, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
	png_time mtime;
	png_convert_from_time_t(&mtime, time(0));
	png_set_tIME(png, info, &mtime);
	png_text text;
	text.compression = PNG_TEXT_COMPRESSION_NONE;
	const std::string &key = "Comment";
	text.key = const_cast<char *>(key.c_str());
	text.text = const_cast<char *>(comment.c_str());
	png_set_text(png, info, &text, 1);
	png_write_info(png, info);
	png_bytepp row = new png_bytep[nHeight];
	for (int y = 0; y < nHeight; ++y)
		row[y] = (png_bytep)(Data + nWidth * nColors * y);
	png_write_image(png, row);
	png_write_end(png, 0);
	delete [] row;
	fclose(file);
	return 1;
}

extern std::string ReadPNGComment(const std::string &filename)
{
	jmp_buf jmpbuf;
	FILE *file = fopen(filename.c_str(), "rb");
	if (! file)
		return "";
	png_structp png = png_create_read_struct(PNG_LIBPNG_VER_STRING, &jmpbuf, kf_png_error_handler, kf_png_warning_handler);
	if (! png)
	{
		fclose(file);
		return "";
	}
	png_infop info = png_create_info_struct(png);
	if (! info)
	{
		png_destroy_read_struct(&png, 0, 0);
		fclose(file);
		return "";
	}
	png_infop enfo = png_create_info_struct(png);
	if (! enfo)
	{
		png_destroy_read_struct(&png, &info, 0);
		fclose(file);
		return "";
	}
	if (setjmp(jmpbuf))
	{
		png_destroy_read_struct(&png, &info, 0);
		fclose(file);
		return "";
	}
	png_init_io(png, file);
	png_read_info(png, info);
	png_textp text;
	int count = 0;
	std::string comment = "";
	if (png_get_text(png, info, &text, &count) > 0)
		for (int t = 0; t < count; t++)
			// we save as capitalized, but processing with ImageMagick downcases
			if (0 == stricmp("Comment", text[t].key))
				comment = text[t].text; // copy
	if (comment == "")
	{
		if (skip_png_image(png, info))
		{
			png_read_end(png, enfo);
			png_textp etext;
			int ecount = 0;
			if (png_get_text(png, enfo, &etext, &ecount) > 0)
				for (int t = 0; t < ecount; t++)
					// we save as capitalized, but processing with ImageMagick downcases
					if (0 == stricmp("Comment", etext[t].key))
						comment = etext[t].text; // copy
		}
	}
	png_destroy_read_struct(&png, &info, &enfo);
	fclose(file);
	return comment;
}

sampling[edit | edit source]

sampling code : https://code.mathr.co.uk/kalles-fraktaler-2/blob/d685883599f7ae795bd7667834b0d2a47c00c7ef:/fraktal_sft/fraktal_sft.cpp#l3314 lines 3314 through 3379 KF does it:

  • generates a hash of (i,j,seed) for each of dx,dy offset (seed is different for x and y)
  • uses that to jitter.

coloring methods[edit | edit source]

KF can export raw iteration data in EXR (and obsolete KFB) formats, so you can colour it with other software, but learning GLSL and writing colouring shaders in KF may be as easy as writing other software. The colouring shaders in Zoomasm 4 (unreleased WIP) are more powerful than KF, because you can add additional uniform variables in the code and control them from the GUI, which makes tweaking things easier. Still only numeric entry fields, which is a bit awkward, and really designed for animation with exponential map sequences.

Pauldelbrot uses a complicated "multiwave" colouring algorithm, different from (and better than) the palette waves in default KFP colouring algorithm. Check the forums for the source code that he posted in a LISP variant (maybe Clojure?). Maybe it's also in the UF formula database somewhere? The key is to have multiple waves of RGB or HSV at different rates, possibly linked to the structure of the fractal (periods etc) that influence each other in complex ways (this is definitely not just separate waves of R G B or H S V, but waves of 3D colours). Also this is done in a different colour space, because blending sRGB values (as used in image files) is wrong (they must be converted to linear first for blending to make any sense).

Claude implemented something possibly similar (but probably not as good) in Rodney, Claude's fractal explorer bot.



One can change it :

  • Main Menu / Actions/ Set Colors
  • keys: Ctrl+C


Available color methods are ( in main.cpp file line 256, variable m_nColorMethod ) :

  • 0 = Standard = Distance (Linear): Standard iteration band coloring
  • 1 = Square root: Iterations are squared before colors are appplied
  • 2 = Cubic root: Cube root is applied before colors
  • 3 = Logarithm: Logarithm is applied before colors = ColorMethod_Logarithm [5]: "ColorMethod_Logarithm is not DEM at all, it's escape time with non-linear transfer function."
  • 4 = Stretched: The palette is stretched over min-max iteration values
  • 5 = Distance: Distance Estimation : "ColorMethod_Distance* have some image processing (looking up iteration values of neighbouring pixels) to generate a pseudo-de colouring. It's not true DEM but looks pretty close sometimes."
  • 6 = DE+Standard




Numbers describing methods ( variable m_nColorMethod) are changing between versions[6]


Code:

  • file fraktal_sft.cpp
  • variable m_nColorMethod
  • functions:
    • CFraktalSFT::SetColorMethod
    • void CFraktalSFT::SetColor
    • CFraktalSFT::OpenFile
    • CFraktalSFT::SaveFile


// fraktal_sft.h
enum ColorMethod
{
	ColorMethod_Standard = 0,
	ColorMethod_SquareRoot = 1,
	ColorMethod_CubicRoot = 2,
	ColorMethod_Logarithm = 3,
	ColorMethod_Stretched = 4,
	ColorMethod_DistanceLinear = 5,
	ColorMethod_DEPlusStandard = 6,
	ColorMethod_DistanceLog = 7,
	ColorMethod_DistanceSqrt = 8,
	ColorMethod_LogLog = 9,
	ColorMethod_ATan = 10,
	ColorMethod_FourthRoot = 11
};

enum Differences
{
	Differences_Traditional = 0,
	Differences_Forward3x3 = 1,
	Differences_Central3x3 = 2,
	Differences_Diagonal2x2 = 3,
	Differences_LeastSquares2x2 = 4,
	Differences_LeastSquares3x3 = 5,
	Differences_Laplacian3x3 = 6,
	Differences_Analytic = 7
};




//fraktal_sft.cpp
void CFraktalSFT::SetColor(int nIndex, int nIter, double offs, int x, int y)
{
	if (nIter<0 || (!g_bShowGlitches && offs==2))
		return;
	if (nIter == m_nMaxIter)
		m_lpBits[nIndex] = m_lpBits[nIndex + 1] = m_lpBits[nIndex + 2] = 0;
	{
		double iter = (double)nIter + (double)1 - offs; // m_nColorMethod = 0;

		if (m_nColorMethod == 1){
			iter = sqrt(iter);
		}
		else if (m_nColorMethod == 2){
			iter = pow(iter, (double)1 / (double)3);
		}
		else if (m_nColorMethod == 3){
			iter = log(iter);
		}
		else if (m_nColorMethod == 4){
			int nMin, nMax;
			GetIterations(nMin, nMax,NULL,NULL,TRUE);
			iter = (double)1024 * ((double)iter - (double)nMin) / ((double)nMax - (double)nMin);
		}
		else if (m_nColorMethod == 5 || m_nColorMethod == 6){
			double p1, p2, p3, p4;
			iter=0;
			if (x){
				p1 = (double)m_nPixels[x - 1][y] + (double)1 - m_nTrans[x - 1][y];
				p2 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
			}
			else if (x<m_nX - 1){
				p1 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
				p2 = (double)m_nPixels[x + 1][y] + (double)1 - m_nTrans[x + 1][y];
			}
			else
				p1 = p2 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
			double _abs_val;
			iter += _abs(p1 - p2)*1.414;

			if (x && y){
				p1 = (double)m_nPixels[x - 1][y - 1] + (double)1 - m_nTrans[x - 1][y - 1];
				p2 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
			}
			else if (x<m_nX - 1 && y<m_nY - 1){
				p1 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
				p2 = (double)m_nPixels[x + 1][y + 1] + (double)1 - m_nTrans[x + 1][y + 1];
			}
			else
				p1 = p2 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
			iter += _abs(p1 - p2);

			if (y){
				p1 = (double)m_nPixels[x][y - 1] + (double)1 - m_nTrans[x][y - 1];
				p2 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
			}
			else if (y<m_nY - 1){
				p1 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
				p2 = (double)m_nPixels[x][y + 1] + (double)1 - m_nTrans[x][y + 1];
			}
			else
				p1 = p2 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
			iter += _abs(p1 - p2)*1.414;

			if (y && x<m_nX-1){
				p1 = (double)m_nPixels[x + 1][y - 1] + (double)1 - m_nTrans[x + 1][y - 1];
				p2 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
			}
			else if (x && y<m_nY - 1){
				p1 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
				p2 = (double)m_nPixels[x - 1][y + 1] + (double)1 - m_nTrans[x - 1][y + 1];
			}
			else
				p1 = p2 = (double)m_nPixels[x][y] + (double)1 - m_nTrans[x][y];
			iter += _abs(p1 - p2);
//			iter/=4;
//			iter*=iter;
			iter*=(double)m_nX / (double)640;
			iter=sqrt(iter);
			/*iter=log(iter);
			if(iter<0)
				iter=0;*/
			if(iter>1024)
				iter=1024;
			if(m_nColorMethod == 6 && iter>m_nIterDiv)
				iter = (double)nIter + (double)1 - offs;
		}
		if (m_nIterDiv != 1){
			iter /= m_nIterDiv;
		}
		if (m_nColorOffset)
			iter += m_nColorOffset;// = (nIter+m_nColorOffset)%1024;
		nIter = (int)iter;
		offs = 1 - (iter - (double)nIter);
		if (m_bITrans)
			offs = 1 - offs;
		if (m_bMW){
			double nH = 0, nS = 0, nB = 0;
			int nDR = 0, nDG = 0, nDB = 0;
			int i;
			for (i = 0; i<m_nMW; i++){
				double nPeriod;
				nPeriod = m_MW[i].nPeriod;
				double g;
				if (m_bTrans)
					g = sin((pi*iter) / nPeriod) / 2 + .5;
				else
					g = sin((pi*((int)iter)) / nPeriod) / 2 + .5;
				if (nPeriod<0)
					g = -(double)nPeriod / (double)100;
				if (m_MW[i].nType == 0){
					nH += g;
					nDR++;
				}
				if (m_MW[i].nType == 1){
					nS += g;
					nDG++;
				}
				if (m_MW[i].nType == 2){
					nB += g;
					nDB++;
				}
			}
			if (nDR)
				nH /= nDR;
			if (nDG)
				nS /= nDG;
			if (nDB)
				nB /= nDB;
			COLOR14 cPos;
			HSVToRGB(nH, nS, nB, cPos);

			m_lpBits[nIndex] = cPos.r;
			m_lpBits[nIndex + 1] = cPos.g;
			m_lpBits[nIndex + 2] = cPos.b;

			if (m_bBlend){
				int nR, nG, nB;
				if (m_bTrans && offs){
					double g1 = (1 - offs);
					int col = nIter % 1024;
					int ncol = (col + 1) % 1024;
					nR = m_cPos[col].r*offs + m_cPos[ncol].r*g1;
					nG = m_cPos[col].g*offs + m_cPos[ncol].g*g1;
					nB = m_cPos[col].b*offs + m_cPos[ncol].b*g1;
				}
				else{
					int col = nIter % 1024;
					nR = m_cPos[col].r;//+n;
					nG = m_cPos[col].g;//+n;
					nB = m_cPos[col].b;//+n;
				}
				m_lpBits[nIndex] = (m_lpBits[nIndex] + nR) / 2;
				m_lpBits[nIndex + 1] = (m_lpBits[nIndex + 1] + nG) / 2;
				m_lpBits[nIndex + 2] = (m_lpBits[nIndex + 2] + nB) / 2;
			}
		}
		else{
			if (m_bTrans && offs){
				double g1 = (1 - offs);
				int col = nIter % 1024;
				int ncol = (col + 1) % 1024;
				m_lpBits[nIndex] = m_cPos[col].r*offs + m_cPos[ncol].r*g1;
				m_lpBits[nIndex + 1] = m_cPos[col].g*offs + m_cPos[ncol].g*g1;
				m_lpBits[nIndex + 2] = m_cPos[col].b*offs + m_cPos[ncol].b*g1;
			}
			else{
				int col = nIter % 1024;
				m_lpBits[nIndex] = m_cPos[col].r;//+n;
				m_lpBits[nIndex + 1] = m_cPos[col].g;//+n;
				m_lpBits[nIndex + 2] = m_cPos[col].b;//+n;
			}
		}
	}

post-processing effects[edit | edit source]

slope[edit | edit source]

  "Slopes rendering is originally a screen-space post-processing effect, using differences between neighbouring pixels' smooth iteration counts.  
   More recently it can use directional distance estimate (normalized by pixel spacing) instead, which I think gerrit proved is equivalent in the   limit of infinitely fine pixel grid. 
   Relevant part of the source code: https://code.mathr.co.uk/kalles-fraktaler- 2/blob/c78c224a4a3ae7f10ed03aa3948f0cd6b740adcb:/fraktal_sft/fraktal_sft.cpp#l933 lines 933 to 998 " Claude


Variables:

  • m_bSlopes = FALSE; is boolean variable
  • m_nSlopePower = 50; is Slope shadow depth, integer
  • m_nSlopeRatio = 50; is Slope shadow strength, integer
  • m_nSlopeAngle = 45; is Slope shadow angle (0-360), integer


Show slopes

  • Enable slope encoding for 3D effect.
  • First value is the magnification of the slopes. The start value of 100 is suitable for the unzoomed view. Deep views requires a couple of magnitudes higher value.
  • The second value is the percentage with which the slope encoding is applied on the coloring. 100 is max, however flat areas will still have the palette color visible.


Algorithm:


 grep -nR "Slope"

tools[edit | edit source]

./kfb-expmap n < x.txt > x.pgm    # exponential map (log polar) with pseudo-de colour ; x.txt lists kfb files one per line, in order ; n is number of kfb files listed in x.txt
./kfb-histogram d < a.kfb > a.pgm # histogram equalize (sort and search, O(N log N)) ; d is density >= 1.0, affects the brightness curve
./kfb-to-mmit < a.kfb > a.mmit  # convert to Mandel Machine iteration data format
./kfb-pseudo-de < a.kfb > a_pde.pgm   # pseudo distance estimate colouring
./kfb-rainbow < a.kfb > a.ppm   # rainbow based on slope direction, plus pseudo-de
./kfb-resize w h < x.kfb > x.kfb  # resize to new (w,h) using bi-cubic interpolation
./kfb-stretch < a.kfb > as.pgm    # simple iteration count stretching

Scripts included ('bash' shell and common linux utilities required):

kfbtoogv.sh s work tmp      # automatic movie maker with sound generation
                              s is desired movie length in seconds
                              work is absolute path to dir containing *.kfb
                              tmp is absolute path to dir for output
                              it checks for the less-common programs it needs


KFMovieMaker[edit | edit source]

Videos:

Effects:


Blending

 grep -nR "Blend"

help[edit | edit source]

references[edit | edit source]

  1. fractalforums.org : additionnal-bailout-variations-on-kalles-fraktaler
  2. towards a common file format for 2D escape time iteration data
  3. fractalforums org: KF file-types
  4. fractalforums org : matlaboctave-code-for-kfb-reading
  5. fractalforums : distance-logarithm-test
  6. fractalforums : kalles-fraktaler/backwards-compatibility