jpegbw

jpegbw

Converts JPEG(s) to B/W.

It actually supports JPEGs, PNGs, GIFs.

usage

Q=90 R=0.2125 G=0.7154 B=0.0721 LO=5 HI=5 GA=1.41 ./jpegbw in.jpg

expression parser

• You can use functions parser for example: F="x1*x2+x3^x4".
• Any math operations are allowed like +, -, /, *, ^ etc.
• Complex number are _ separated, for example: 3_1 means 3+i, _1 means 0+i, _0 means 0+0i, 1_ or 1 means just 1+0i. _ means 0+0i.
• You can group expreccions using ( ), for example F="(x1+x2)*x3".
• Functions can take 1, 2, 3 or 4 arguments.
• x1 will be replaced with greyscale value of current pixel, range is 0-1.
• x2 will be replaced with current pixel's x and y position x+yi , range is 0-1.
• x3 will be replaced with current pixel's red and green colors r+gi, range is 0-1.
• x4 will be replaced with current pixel's blue and alpha colors b+ai, range is 0-1.
• x5 will be replaced with number indicating processing file number (scaled), and previous pixel's value pn+prev*i range is 0-1.
• You can also call functions from external C libraries.

external functions

• To use external C function you must provide path to a dynamic library (.so on linux, .dylib on mac, .dll on windows etc).
• Library path example on mac: LIB="/usr/lib/libm.dylib". Usually the math lib is what you need, linux: LIB="/usr/lib/libm.so".
• Example usage: time LIB="/lib/aarch64-linux-gnu/libm-2.24.so" F="sin(x1*3.14159)^2" jpegbw in.jpg.
• You can use max up to 4-args functions, example: R=0.25 G=0.6 B=0.15 LO=3 HI=3 LIB="/usr/lib/libm.dylib" F="fma(x2,x3,x1)" ./jpegbw in.png.
• Other: time R=0.25 G=0.6 B=0.15 LO=6 HI=6 LIB="/usr/lib/libm.dylib" F="((fma(x2,x3,x1)+fma(1-x2,x3,x1)+fma(x2,1-x3,x1)+fma(1-x2,1-x3,x1))/4)^2" ./jpegbw in.png.
• Using local C library libjepgbw.so: LIB="./libjepgbw.so" F="func(x1)" ./jpegbw in.png.
• After make install just: LIB="libjepgbw.so" F="func(x1)" jpegbw in.png.
• Toon function: LIB="libjepgbw.so" F="toon(x1,5)" jpegbw in.png.
• Vingette function: LIB="libjepgbw.so" F="vingette(x1, x2, x3)" jpegbw in.png.
• Alpha function: LIB="libjepgbw.so" F="alpha(x1, x2, x3, 1.4)" jpegbw in.png.

multithreading

• Use N=4 to specify to run using 4 threads, if no N is defined it will use Go runtime to get number of cores available.

combine 3 grayscale images into RGB image

• See combine*.sh scripts.

other

• Use O=".jpg:.png" to overwite file name config. This will save JPG as PNG.

build

• go get github.com/andybons/gogif
• make && make install.
• If you don't have tools required for make check do sudo ./deps.sh.
• If you still have any issues with additional check, compile binaries directly: make jpegbw libjpegbw.so libbyname.so.
• You can build debug binaries by using conditional compilation (gengo + gen.sh tools).
• Those tools are specially written to allow no additional overhead on non-debug binaries.

install

• First build and then sudo make install.
• Package: go get github.com/lukaszgryglicki/jpegbw.

development

• Edit *.pgo files instead of *.go files.
• Once done run ./gen.sh.
• *.go files are generated from *.pgo files.

cmap

Program to generate complex functions contour charts:

• Run cmap to see help.
• Example: LIB="libjpegbw.so" X=1600 Y=1600 K=2 R0=-1 R1=4 I0=-4 I1=4 ./cmap complex_log.png "clog(x1)"

(1600 x 1600) Real: [-1.000000,4.000000] Imag: [-4.000000,4.000000] Threads: 8
Values range: (-5.960527040805936-3.1390910953307114i) - (1.7328679513998633+3.139091095330712i), modulo range: 0.002795 - 6.116321, lines range: -5.960527 - 1.732868
Processed in: 22.294005s, MPPS: 0.110, 0
Real values from minimum to max are: red --> cyan/teal
Imag values from minimum to max are: blue --> yellow
Modulo values from minimum to max are: green --> pink
Re = 0 red almost white
Im = 0 blue almost white
Mod = 0 green almost white
Complex plane Re = 0, Im = 0 and modulo unit circle: white
Time: 22.294628s

tetration

• There is a tetration library libtet.so.
• You can test it via: clear; LIB="./libtet.so" ./cmap out.jpg 'tettest(1,_1,0.5,_1)'
• You can use functions from the tetration library (see tet.c, tet.h):
  • tet(z) complex natural tetration of z (base e).
  • ate(z) complex natural abel-tetration (aka super logarithm) of z (base e).
  • hexp(z, h) - partial iterate of exp(z) function. For example h=1 --> exp(x), 2=2 --> exp(exp(x)), h=0 -> x, but h=0.5 half iterate exponential.
  • h in hexp(z, h) is complex, so you can make i-iterate of exp(z) via: hexp(z, _1).
• tettest function calls C exit internally, it is supposed to be called once with 4 args to call various combinations of all functions mentioned above.
• All those functions can be used to generate contour charts of tetration, super log, half iterate exp etc.

'f' program

• Can be used to compute up to 4 args complex function
• You must provide 2 to 5 args: function def and 1-4 arguments
• Example: LIB="./libtet.so" ./f 'csin(x1)*ccos(x2)*cpow(x3, x4)' 1 -2 _3 -_4
• Other example (simplest): ./f 'x1+x2' 3 _4 produces:

f(3+0i, 0+4i) = 3+4i
|'x1+x2'(3, _4)| = 5